ALBERT

Description: 〈b〉Validating improved-MODIS products from spectral mixture-Landsat snow cover maps in a mountain region in southern Spain〈/b〉〈br〉 Rafael Pimentel, Carlo Marín, Ludovica De Gregorio, Mattia Callegari, María J. Pérez-Palazón, Claudia Notarnicola, and María J. Polo〈br〉 Proc. IAHS, 380, 67-72, https://doi.org/10.5194/piahs-380-67-2018, 2018〈br〉 In Mediterranean regions, the spatiotemporal evolution of the snow cover can experiment quick changes and high frequency sensors are required to adequately monitor such shifts. This work presents a methodological approach to validate the improved MODIS daily snow cover maps, in a Sierra Nevada (southern Spain), from a reference data set obtained by Landsat TM data. The results show a significantly high correlation between the two snow map products at differents spatial scale.

Description: 〈b〉Joint editorial: Invigorating hydrological research through journal publications〈/b〉〈br〉 Nevil Quinn, Günter Blöschl, András Bárdossy, Attilio Castellarin, Martyn Clark, Christophe Cudennec, Demetris Koutsoyiannis, Upmanu Lall, Lubomir Lichner, Juraj Parajka, Christa D. Peters-Lidard, Graham Sander, Hubert Savenije, Keith Smettem, Harry Vereecken, Alberto Viglione, Patrick Willems, Andy Wood, Ross Woods, Chong-Yu Xu, and Erwin Zehe〈br〉 Proc. IAHS, 380, 3-8, https://doi.org/10.5194/piahs-380-3-2018, 2018〈br〉 〈p〉Editors of several journals in the field of hydrology met during the General Assembly of the European Geosciences Union (EGU) in Vienna in April 2017. This event was a follow-up of similar meetings held in 2013 and 2015. These meetings enable the group of editors to review the current status of the journals and the publication process, and to share thoughts on future strategies. Journals were represented at the 2017 meeting by their editors, as shown in the list of authors. The main points on invigorating hydrological research through journal publications are communicated in this joint editorial published in the above journals.〈/p〉

Description: 〈b〉Image acquisition effects on Unmanned Air Vehicle snow depth retrievals〈/b〉〈br〉 Ahmet Emre Tekeli and Senayi Dönmez〈br〉 Proc. IAHS, 380, 81-85, https://doi.org/10.5194/piahs-380-81-2018, 2018〈br〉 Current study is unique in that the SD retrievals were derived using two different image acquisition modes. In the first, images were taken as UAV was continuously flying and in the second UAV kept its position in air fixed as the photos were taken. Root mean square error of derived SDs is found as 2.43 and 1.79 cm in continuous and fixed acquisitions. The results support the hypothesis, that fixed-position image acquisitions using multi-rotor platforms should enable more accurate SD estimates.

Description: 〈b〉Preface: Earth Observation for Integrated Water and Basin Management: Challenges for adaptation to a changing environment〈/b〉〈br〉 María J. Polo, Maria P. González-Dugo, and Christopher Neale〈br〉 Proc. IAHS, 380, 1-2, https://doi.org/10.5194/piahs-380-1-2018, 2018〈br〉

Description: 〈b〉Remote sensing vegetation index methods to evaluate changes in greenness and evapotranspiration in riparian vegetation in response to the Minute 319 environmental pulse flow to Mexico〈/b〉〈br〉 Pamela L. Nagler, Christopher J. Jarchow, and Edward P. Glenn〈br〉 Proc. IAHS, 380, 45-54, https://doi.org/10.5194/piahs-380-45-2018, 2018〈br〉 Our study examined the effects of water transfer, or ecological environmental flows, from one country to another. We studied the impact of a historic, binational, water release, Minute 319 of the 1944 Water Treaty, on vegetative response along the riparian corridor on the lower Colorado River to Mexico. During the spring of 2014, 130 million cubic meters of water were released from the United States to Mexico, allowing water to reach the Gulf of California for the first time in 13 years.

Description: 〈b〉Effect of the water stress on gross primary production modeling of a Mediterranean oak savanna ecosystem〈/b〉〈br〉 Pedro J. Gómez-Giráldez, Elisabet Carpintero, Mario Ramos, Cristina Aguilar, and María P. González-Dugo〈br〉 Proc. IAHS, 380, 37-43, https://doi.org/10.5194/piahs-380-37-2018, 2018〈br〉 This work investigates the effect of different parameterizations to account for water stress on GPP estimates and their agreement with observations. GPP is estimated with a LUE-model in the footprint of the EC tower using several approaches. The preliminary results obtained during two hydrological years (2015/2016 and 2016/2017) are compared, focusing on specific wet and dry periods.

Description: 〈b〉Use of Sentinel 2 – MSI for water quality monitoring at Alqueva reservoir, Portugal〈/b〉〈br〉 Miguel Potes, Gonçalo Rodrigues, Alexandra Marchã Penha, Maria Helena Novais, Maria João Costa, Rui Salgado, and Maria Manuela Morais〈br〉 Proc. IAHS, 380, 73-79, https://doi.org/10.5194/piahs-380-73-2018, 2018〈br〉 The Alqueva reservoir is located in the southeast of Portugal. This region is facing an increase in droughts and a degradation in water quality mainly due to more frequent and lasting phytoplancton blooms. With satellite remote sensing is possible to monitoring such reservoirs. In this study, Sentinel-2 presents very good estimation for chlorophyll a, cyanobacteria and water turbidity during a micro algae bloom that vanished due to the approximation of hurricane Ophelia to Iberian Peninsula.

Description: 〈b〉Evapotranspiration and evaporation/transpiration partitioning with dual source energy balance models in agricultural lands〈/b〉〈br〉 Gilles Boulet, Emilie Delogu, Sameh Saadi, Wafa Chebbi, Albert Olioso, Bernard Mougenot, Pascal Fanise, Zohra Lili-Chabaane, and Jean-Pierre Lagouarde〈br〉 Proc. IAHS, 380, 17-22, https://doi.org/10.5194/piahs-380-17-2018, 2018〈br〉 Mapping of transpiration T and evaporation E is crucial for assessing plant water use and plant water status at landscape scale. Dual-source energy balance models forced by thermal infrared observations provide separate estimates of E and T but rely on specific assumptions to get both terms from the sole surface temperature. We show here with a synthetic experiment that additional information is thus required, e.g. surface water content that can be derived from radar.

Description: 〈b〉Assessment of SMADI and SWDI agricultural drought indices using remotely sensed root zone soil moisture〈/b〉〈br〉 Miriam Pablos, Ángel González-Zamora, Nilda Sánchez, and José Martínez-Fernández〈br〉 Proc. IAHS, 380, 55-66, https://doi.org/10.5194/piahs-380-55-2018, 2018〈br〉 〈p〉The increasing frequency of drought events has expanded the research interest in drought monitoring. In this regard, remote sensing is a useful tool to globally mapping the agricultural drought. While this type of drought is directly linked to the availability of root zone soil moisture (RZSM) for plants growth, current satellite soil moisture observations only characterize the water content of the surface soil layer (0–5 〈span〉cm〈/span〉). In this study, two soil moisture-based agricultural drought indices were obtained at a weekly rate from June 2010 to December 2016, using RZSM estimations at 1 〈span〉km〈/span〉 from the Soil Moisture and Ocean Salinity (SMOS) satellite, instead of surface soil moisture (SSM). The RZSM was estimated by applying the Soil Water Index (SWI) model to the SMOS SSM. The Soil Moisture Agricultural Drought Index (SMADI) and the Soil Water Deficit Index (SWDI) were assessed over the Castilla y León region (Spain) at 1 〈span〉km〈/span〉 spatial resolution. They were compared with the Atmospheric Water Deficit (AWD) and the Crop Moisture Index (CMI), both computed at different weather stations distributed over the study area. The level of agreement was analyzed through statistical correlation. Results showed that the use of RZSM does not influence the characterization of drought, both for SMADI and SWDI.〈/p〉

Description: 〈b〉Use of canopy coefficients obtained from satellite data to estimate evapotranspiration over high mountain Mediterranean watersheds〈/b〉〈br〉 Elisabet Carpintero, María P. González-Dugo, Jorge Jódar, and Sergio Martos-Rosillo〈br〉 Proc. IAHS, 380, 23-28, https://doi.org/10.5194/piahs-380-23-2018, 2018〈br〉 This work monitors the water consumed by the vegetation in two watersheds of Southern Spain for two years. An approach based on the reference evapotranspiration (ETo) and vegetation indices (VIs)-derived canopy coefficients is used (VI-ETo approach). A spatial analysis of ET of the main vegetation types was performed. The annual runoff, estimated with a simple water balance and using the ET, was similar to that obtained by the HBV model, which reproduces the river discharge at the outlet.

Description: 〈b〉Monitoring environmental supporting conditions of a raised bog using remote sensing techniques〈/b〉〈br〉 Saheba Bhatnagar, Bidisha Ghosh, Shane Regan, Owen Naughton, Paul Johnston, and Laurence Gill〈br〉 Proc. IAHS, 380, 9-15, https://doi.org/10.5194/piahs-380-9-2018, 2018〈br〉 〈p〉Conventional methods of monitoring wetlands and detecting changes over time can be time-consuming and costly. Inaccessibility and remoteness of many wetlands is also a limiting factor. Hence, there is a growing recognition of remote sensing techniques as a viable and cost-effective alternative to field-based ecosystem monitoring. Wetlands encompass a diverse array of habitats, for example, fens, bogs, marshes, and swamps. In this study, we concentrate on a natural wetland – Clara Bog, Co. Offaly, a raised bog situated in the Irish midlands. The aim of the study is to identify and monitor the environmental conditions of the bog using remote sensing techniques. Environmental conditions in this study refer to the vegetation composition of the bog and whether it is in an intact (peat-forming) or degraded state. It can be described using vegetation, the presence of water (soil moisture) and topography. Vegetation indices (VIs) derived from satellite data have been widely used to assess variations in properties of vegetation. This study uses mid-resolution data from Sentinel-2 MSI, Landsat 8 OLI for VI analysis. An initial study to delineate the boundary of the bog using the combination of edge detection and segmentation techniques namely, entropy filtering, canny edge detection, and graph-cut segmentation is performed. Once the bog boundary is defined, spectra of the delineated area are studied. VIs like NDVI, ARVI, SAVI, NDWI, derived using Sentinel-2 MSI and Landsat 8 OLI are analysed. A digital elevation model (DEM) was also used for better classification. All of these characteristics (features) serve as a basis for classifying the bog into broad vegetation communities (termed 〈q〉ecotopes〈/q〉) that indicate the quality of raised bog habitat. This analysis is validated using field derived ecotopes. The results show that, by using spectral information and vegetation index clustering, an additional linkage can be established between spectral RS signatures and wetland ecotopes. Hence, the benefit of the study is in understanding ecosystem (bog) environmental conditions and in defining appropriate metrics by which changes in the conditions can be monitored.〈/p〉

Description: 〈b〉Remote sensing-based soil water balance for irrigation water accounting at the Spanish Iberian Peninsula〈/b〉〈br〉 Jesús Garrido-Rubio, Alfonso Calera Belmonte, Lorena Fraile Enguita, Irene Arellano Alcázar, Mario Belmonte Mancebo, Isidro Campos Rodríguez, and Raquel Bravo Rubio〈br〉 Proc. IAHS, 380, 29-35, https://doi.org/10.5194/piahs-380-29-2018, 2018〈br〉 The temporal series of thematically cartography about irrigated areas and corresponding irrigation water requirements based on remote sensing, is a recognized tool to water governance at different scales. Main products generated for the Spanish mainland, 2014–2017, using a multisensor constellation of Landsat 8 and Sentinel-2 satellites are: annual maps of irrigated crops and; monthly and annual maps of remote sensing-based irrigation water accounting by a remote sensing-based soil water balance

Description: 〈b〉Centralized versus distributed reservoirs: an investigation of their implications on environmental flows and sustainable water resources management〈/b〉〈br〉 Nishadi Eriyagama, Vladimir Smakhtin, and Lakshika Udamulla〈br〉 Proc. IAHS, 379, 43-47, https://doi.org/10.5194/piahs-379-43-2018, 2018〈br〉 Creation of surface storage often endanger the functions of natural ecosystems and ecosystem services. The issues of optimal size, placement and the number of reservoirs in a river basin, which maximizes sustainable benefits, while minimizing negative impacts on ecosystems remain subjects for debate. This study examines the above issues through the analysis of a range of reservoir configurations and environmental flow release scenarios in the Malwatu Oya river basin in Sri Lanka.

Description: 〈b〉Application of remote sensing data for measuring freshwater ecosystems changes below the Zeya dam in the Russian Far East〈/b〉〈br〉 Oxana I. Nikitina, Kirill Y. Bazarov, and Evgeny G. Egidarev〈br〉 Proc. IAHS, 379, 49-53, https://doi.org/10.5194/piahs-379-49-2018, 2018〈br〉 Large dams cause extensive environmental impacts. The Zeya hydropower dam is located on the left-bank tributary of the Amur-Heilong, one of the ten largest rivers on Earth. The territory affected by the Zeya dam comprises biodiverse areas. An estimation of the transformation of the freshwater ecosystems is required to develop measures necessary either to maintain or restore disrupted ecosystems. Application of remote sensing methods allows measuring characteristics of the ecosystem's components.

Description: 〈b〉Village-level supply reliability of surface water irrigation in rural China: effects of climate change〈/b〉〈br〉 Yanrong Li and Jinxia Wang〈br〉 Proc. IAHS, 379, 89-104, https://doi.org/10.5194/piahs-379-89-2018, 2018〈br〉 Econometric results revealed that temperature is negatively related with the supply reliability of surface water irrigation; but precipitation positively influences the supply reliability of surface water irrigation. For instance, increasing temperature by 0.5 °C will reduce the supply reliability of surface water irrigation by 1.1 %. When precipitation increases by 10 %, the supply reliability can be increased by 4.6 %. Besides, climate influence differs by seasons.

Description: 〈b〉An assessment of temporal effect on extreme rainfall estimates〈/b〉〈br〉 Samiran Das, Dehua Zhu, and Cheng Chi-Han〈br〉 Proc. IAHS, 379, 145-150, https://doi.org/10.5194/piahs-379-145-2018, 2018〈br〉 This study assesses the temporal behaviour in terms of inter-decadal variability of extreme daily rainfall of stated return period relevant for hydrologic risk analysis using a novel regional parametric approach. The assessment is carried out based on annual maximum daily rainfall series of 180 meteorological stations of Yangtze River Basin over a 50-year period (1961–2010). The outcomes of the analysis reveal that while there were effects present indicating higher quantile values when estimated from data of the 1990s, it is found not to be noteworthy to exclude the data of any decade from the extreme rainfall estimation process for hydrologic risk analysis.

Description: 〈b〉Analysis of vegetation condition and its relationship with meteorological variables in the Yarlung Zangbo River Basin of China〈/b〉〈br〉 Xianming Han, Depeng Zuo, Zongxue Xu, Siyang Cai, and Xiaoxi Gao〈br〉 Proc. IAHS, 379, 105-112, https://doi.org/10.5194/piahs-379-105-2018, 2018〈br〉 To further protect the ecology of the study area, remote sensing image technology is used to analyze the temporal and spatial distribution characteristics of vegetation in the Yarlung Zangbo River Basin by splicing the remote sensing image of a time series (from February 2000 to December 2016). It can be found that vegetation coverage is better in low elevation areas,vegetation change shows a weak sustainability and the vegetation growth is more affected by the temperature than the precipitation.

Description: 〈b〉Impact of urbanization on flood of Shigu creek in Dongguan city〈/b〉〈br〉 Luying Pan, Yangbo Chen, and Tao Zhang〈br〉 Proc. IAHS, 379, 55-60, https://doi.org/10.5194/piahs-379-55-2018, 2018〈br〉 Due to rapid urbanization, quick flood response has been observed in Shigu creek, which posted great threat to the flood security. In this paper, the Land cover/use changes of Shigu creek from 1987–2015 induced by urbanization was extracted and the Liuxihe Model was employed to simulate the flood processes impacted by urbanization. Precipitation of 3 storms was used for flood processes simulation. The results show that the runoff coefficient and peak flow have increased sharply.

Description: 〈b〉Spatiotemporal variability and assessment of drought in the Wei River basin of China〈/b〉〈br〉 Siyang Cai, Depeng Zuo, Zongxue Xu, Xianming Han, and Xiaoxi Gao〈br〉 Proc. IAHS, 379, 73-82, https://doi.org/10.5194/piahs-379-73-2018, 2018〈br〉 Drought is a natural and recurring feature of climate; occurring in virtually all climatic regimes. Wei River is of great importance in social and economic in China. The temporal and spatial variations of drought in the Wei River basin were investigated by calculating the drought indexes. Through analysis of the historical precipitation and temperature data, it was found that precipitation had a greater contribution to creating agricultural drought conditions than temperature.

Description: 〈b〉Assessment of freshwater ecosystem services in the Beas River Basin, Himalayas region, India〈/b〉〈br〉 Sikhululekile Ncube, Lindsay Beevers, Adebayo J. Adeloye, and Annie Visser〈br〉 Proc. IAHS, 379, 67-72, https://doi.org/10.5194/piahs-379-67-2018, 2018〈br〉 The aim of this study is to understand the impact of flow regulation on supporting ecosystem services in the Beas Basin in India, using macroinvertebrates as an indicator. Findings show that both river flows and macroinvertebrate abundance have decreased overtime in the Beas Basin. Consequently, this could have a detrimental impact on instream supporting ecosystem services delivery. Such an understanding is important in future water resources management in the Beas River Basin.

Description: 〈b〉Hydrological regionalisation based on available hydrological information for runoff prediction at catchment scale〈/b〉〈br〉 Qiaoling Li, Zhijia Li, Yuelong Zhu, Yuanqian Deng, Ke Zhang, and Cheng Yao〈br〉 Proc. IAHS, 379, 13-19, https://doi.org/10.5194/piahs-379-13-2018, 2018〈br〉 Regionalisation provides a way of transferring hydrological information from gauged to ungauged catchments. The past few decades has seen several kinds of regionalisation approaches for catchment classification and runoff predictions. The underlying assumption is that catchments having similar catchment properties are hydrological similar. This requires the appropriate selection of catchment properties, particularly the inclusion of observed hydrological information, to explain the similarity of hydrological behaviour. We selected observable catchments properties and flow duration curves to reflect the hydrological behaviour, and to regionalize rainfall-runoff response for runoff prediction. As a case study, we investigated 15 catchments located in the Yangtze and Yellow River under multiple hydro-climatic conditions. A clustering scheme was developed to separate the catchments into 4 homogeneous regions by employing catchment properties including hydro-climatic attributes, topographic attributes and land cover etc. We utilized daily flow duration curves as the indicator of hydrological response and interpreted hydrological similarity by root mean square errors. The combined analysis of similarity in catchment properties and hydrological response suggested that catchments in the same homogenous region were hydrological similar. A further validation was conducted by establishing a rainfall-runoff coaxial correlation diagram for each catchment. A common coaxial correlation diagram was generated for each homogenous region. The performances of most coaxial correlation diagrams met the national standard. The coaxial correlation diagram can be transferred within the homogeneous region for runoff prediction in ungauged catchments at an hourly time scale.

Description: 〈b〉Development of an integrated model for the Campaspe catchment: a tool to help improve understanding of the interaction between society, policy, farming decision, ecology, hydrology and climate〈/b〉〈br〉 Takuya Iwanaga, Fateme Zare, Barry Croke, Baihua Fu, Wendy Merritt, Daniel Partington, Jenifer Ticehurst, and Anthony Jakeman〈br〉 Proc. IAHS, 379, 1-12, https://doi.org/10.5194/piahs-379-1-2018, 2018〈br〉 Improving management of water resources requires understanding of the natural and human components and drivers that influence the resources, and how these interact. Development of an integrated modelling process can be useful for gaining and sharing understanding of the impact of the interactions. Here we have developed such a modelling process for the Campaspe basin in northern Victoria, Australia. The model has been used to explore the impact of various scenarios on the water resources.

Description: 〈b〉Reservoirs operation and water resources utilization coordination in Hongshuihe basin〈/b〉〈br〉 Chonghao Li, Kaige Chi, Bo Pang, and Hongbin Tang〈br〉 Proc. IAHS, 379, 125-129, https://doi.org/10.5194/piahs-379-125-2018, 2018〈br〉 The reservoirs of cascade hydropower stations in Hongshuihe basin are facing more and more integrated water resources utilization problem. This paper introduces the integrated water demand of cascade reservoirs in Hongshuihe and analyses the impact of various types of integrated water demand on power generation. It provides a technical and management guide and demonstration for cascade reservoirs operation and basin integrated water management.

Description: 〈b〉Climate change impact on streamflow in large-scale river basins: projections and their uncertainties sourced from GCMs and RCP scenarios〈/b〉〈br〉 Olga N. Nasonova, Yeugeniy M. Gusev, Evgeny E. Kovalev, and Georgy V. Ayzel〈br〉 Proc. IAHS, 379, 139-144, https://doi.org/10.5194/piahs-379-139-2018, 2018〈br〉 Projections of climate induced changes in streamflow of 11 large-scale rivers located in five continents were modeled up to 2100 using meteorological projections simulated by five global circulation models (GCMs) for four climatic scenarios. Contribution of different sources of uncertainties into a total uncertainty of river runoff projections was analyzed. It was found that contribution of GCMs into the total uncertainty is, on the average, nearly twice larger than that of climatic scenarios.

Description: 〈b〉Sources and behavior of perchlorate ions (ClO〈sub〉4〈/sub〉〈sup〉−〈/sup〉) in chalk aquifer of Champagne-Ardenne, France: preliminary results〈/b〉〈br〉 Feifei Cao, Jessy Jaunat, Patrick Ollivier, Benjamin Cancès, Xavier Morvan, Daniel Hubé, Alain Devos, Nicolas Devau, Vincent Barbin, and Pierre Pannet〈br〉 Proc. IAHS, 379, 113-117, https://doi.org/10.5194/piahs-379-113-2018, 2018〈br〉 Perchlorate can be a health concern due to its its ability to disrupt the thyroid gland's use of iodine. High perchlorate concentrations have been reported in chalk groundwater of Champagne-Ardennes (France). Water samples at 35 sampling points were analysed in order to determine the sources and behaviors of perchlorate. The preliminary results shows that most of the water samples showing high perchlorate levels were collected near a military camp, representing a potential source of perchlorate.

Description: 〈b〉Understanding the potential sources and environmental impacts of dissolved and suspended organic carbon in the diversified Ramganga River, Ganges Basin, India〈/b〉〈br〉 Mohd Yawar Ali Khan and Fuqiang Tian〈br〉 Proc. IAHS, 379, 61-66, https://doi.org/10.5194/piahs-379-61-2018, 2018〈br〉 This study has been conducted on Ramganga River, a major tributary of Ganges River, India, to observe the spatial variation of DOC, dissolved inorganic carbon (DIC), SOC and suspended inorganic carbon (SIC) in river water. The significant conclusions of this investigation revealed that the river and its tributaries show abundance amount of TSC (SOC and SIC) and TDC (DOC and DIC) both in the upstream and downstream. TDC accounts more in river concentration as compared to TSC.

Description: 〈b〉Effect of reservoir zones and hedging factor dynamism on reservoir adaptive capacity for climate change impacts〈/b〉〈br〉 Adebayo J. Adeloye and Bankaru-Swamy Soundharajan〈br〉 Proc. IAHS, 379, 21-29, https://doi.org/10.5194/piahs-379-21-2018, 2018〈br〉 We assessed the effects of different modes of operating reservoir on its ability to moderate water shortage impacts caused by climate change. The operating rule approach was enhanced by hedging using multiple zones and monthly rationing ratios for curtailment of water release. The results showed that basic hedging with single zone and constant rationing ratio caused significant reduction in water shortage during severe droughts. More complex operation modes produced only modest improvement.

Description: 〈b〉Study on reservoir time-varying design flood of inflow based on Poisson process with time-dependent parameters〈/b〉〈br〉 Jiqing Li, Jing Huang, and Jianchang Li〈br〉 Proc. IAHS, 379, 119-123, https://doi.org/10.5194/piahs-379-119-2018, 2018〈br〉 The time-varying design flood is a dynamic design flood, which considers the shortage of water resources and followed the law of flood evolution in reservoir operation. Compared with the traditional design flood, time-varying design flood can make full use of the measured data, reflect the actual situation of the reservoir and so on. Using time-varying design flood to develop a reservoir operation plan not only ensures reservoir safety but also effectively improves water resource utilization.

Description: 〈b〉Framework for quantifying flow and sediment yield to diagnose and solve the aggradation problem of an ungauged catchment〈/b〉〈br〉 Sagar Kumar Tamang, Wenjun Song, Xing Fang, Jose Vasconcelos, and J. Brian Anderson〈br〉 Proc. IAHS, 379, 131-138, https://doi.org/10.5194/piahs-379-131-2018, 2018〈br〉 The opening of the bridge changed from several feet to a few inches due to sediment deposition. The hydrologic model was used to simulate discharges and then sediment generation from the watershed. The study watershed is ungauged and does not have data for model calibration, therefore, a parameter transfer method is used. Basically, a hydrologic model was developed and calibrated for a nearby watershed with streamflow data, and then model parameters are transferred to the ungauged watershed.

Description: 〈b〉Methodology to explore emergent behaviours of the interactions between water resources and ecosystem under a pluralistic approach〈/b〉〈br〉 Glenda García-Santos, Mariana Madruga de Brito, Britta Höllermann, Linda Taft, Adrian Almoradie, and Mariele Evers〈br〉 Proc. IAHS, 379, 83-87, https://doi.org/10.5194/piahs-379-83-2018, 2018〈br〉 Our study presents the utility of a system dynamics modelling approach for water management and decision-making for the case of a forest ecosystem under risk of wildfires. We use the pluralistic water research concept to explore different scenarios and simulate the emergent behaviour of water interception and net precipitation after a wildfire in a forest ecosystem. Through a case study, we illustrate the applicability of this new methodology.

Description: 〈b〉Understanding the Impacts of Climate Change in the Tana River Basin, Kenya〈/b〉〈br〉 Lal Muthuwatta, Aditya Sood, Matthew McCartney, Nishchitha Sandeepana Silva, and Alfred Opere〈br〉 Proc. IAHS, 379, 37-42, https://doi.org/10.5194/piahs-379-37-2018, 2018〈br〉 In the Tana River Basin in Kenya, six Regional Circulation Models (RCMs) simulating two Representative Concentration Pathways (RCPs) (i.e., 4.5 and 8.5) were used as input to the Soil and Water Assessment Tool (SWAT) model to determine the possible implications for the hydrology and water resources of the basin. Four hydrological characteristics – water yield, groundwater recharge, base flow and flow regulation – were determined and mapped throughout the basin for three 30-year time periods: 2020–2049, 2040–2069 and 2070–2099. Results were compared with a baseline period, 1983–2011. All four hydrological characteristics show steady increases under both RCPs for the entire basin but with considerable spatial heterogeneity and greater increases under RCP 8.5 than RCP 4.5. The results have important implications for the way water resources in the basin are managed. It is imperative that water managers and policy makers take into account the additional challenges imposed by climate change in operating built infrastructure.

Description: 〈b〉Stability and tilting of regional water cycle over Tarim Basin〈/b〉〈br〉 Hongquan Zhang and Zhuguo Ma〈br〉 Proc. IAHS, 379, 31-36, https://doi.org/10.5194/piahs-379-31-2018, 2018〈br〉 The water consumption imbalance in Tarim Basin is caused by human activities and tilts the humidity profile over the basin. As a result, more water vapour spills from the western part of the basin and causes precipitation to increase in adjacent areas. At the same time, the Westerlies carry the low humidity air mass out of the eastern part of the basin to make the downwind Gobi Desert and surrounding areas drier.

Description: 〈b〉Estimating lake-water evaporation from data of large-aperture scintillometer in the Badain Jaran Desert, China, with two comparable methods〈/b〉〈br〉 Peng-Fei Han, Xu-Sheng Wang, Xiaomei Jin, and Bill X. Hu〈br〉 Proc. IAHS, 379, 433-442, https://doi.org/10.5194/piahs-379-433-2018, 2018〈br〉 〈p〉Accurate quantification of evaporation (〈span〉〈i〉E〈/i〉〈sub〉0〈/sub〉〈/span〉) from open water is vital in arid regions for water resource management and planning, especially for lakes in the desert. The scintillometers are increasingly recognized by researchers for their ability to determine sensible (〈span〉〈i〉H〈/i〉〈/span〉) and latent heat fluxes (LE) accurately over distances of hundreds of meters to several kilometers, though scintillometers are mainly used to monitor the land surface processes. In this paper, it is installed on both sides of the shore over a lake. Compared to the data of evaporationpan, the scintillometer was successfully applied to Sumu Barun Jaran in Badain Jaran Desert using the classical method and the proposed linearized 〈span〉〈i〉β〈/i〉〈/span〉 method. Due to the difficulty in measuring water surface temperature and the easiness to monitor the water temperature at different depths, it is worth thinking that if is feasible to utilize the shallow water temperature instead of the water surface temperature and how much errors it will cause. Water temperature at 10 and 20 cm depths were used to replace the lakewater surface temperature in the two methods to analyze the changes of sensible and latent heat fluxes in hot and cold seasons at halfhour time scales. Based on the classical method, the values of 〈span〉〈i〉H〈/i〉〈/span〉 were almost barely affected, and the average value of LE using water temperature at 20 cm depth is 0.8–9.5 % smaller than that at 10 cm depth in cold seasons. In hot seasons, compared to the results at 10 cm depth, the average value of 〈span〉〈i〉H〈/i〉〈/span〉 increased by 20–30 %, and LE decreased by about 20 % at 20 cm depth. In the proposed linearized 〈span〉〈i〉β〈/i〉〈/span〉 method of scintillometer, only the slope of the saturation pressure curve (〈span〉Δ〈/span〉) is related to the water surface temperature, which was estimated using available equations of saturated vapor pressure versus temperature of the air. Compared to the values of estimated by the air temperature, while the water surface temperature are replaced by water temperature at 10 and 20 cm depths, in different seasons, the errors of 2–25 % in 〈span〉Δ〈/span〉 were caused. Thus was calculated by the original equation in the proposed linearized 〈span〉〈i〉β〈/i〉〈/span〉 method of scintillometer. Interestingly, the water temperature at 10 and 20 cm depths had little effect on 〈span〉〈i〉H〈/i〉〈/span〉, LE (〈span〉〈i〉E〈/i〉〈sub〉0〈/sub〉〈/span〉) in different seasons. The reason is that the drying power of the air (〈span〉〈i〉E〈/i〉〈sub〉A〈/sub〉〈/span〉) accounted for about 85 % of the evaporation (i.e. the changes of 〈span〉Δ〈/span〉 have only about 3 % impact on evaporation), which indicated that the driving force from unsaturated to saturated vapor pressure at 2 m height (i.e. the aerodynamic portion) has the main role on evaporation. Therefore, the proposed linearized 〈span〉〈i〉β〈/i〉〈/span〉 method of scintillometer is recommended to quantify the 〈span〉〈i〉H〈/i〉〈/span〉, LE (〈span〉〈i〉E〈/i〉〈sub〉0〈/sub〉〈/span〉) over open water, especially when the water surface temperature cannot be accurately measured.〈/p〉

Description: 〈b〉Connections between meteorological and hydrological droughts in a semi-arid basin of the middle Yellow River〈/b〉〈br〉 Binquan Li, Changchang Zhu, Zhongmin Liang, Guoqing Wang, and Yu Zhang〈br〉 Proc. IAHS, 379, 403-407, https://doi.org/10.5194/piahs-379-403-2018, 2018〈br〉 Differences between meteorological and hydrological droughts could reflect the regional water consumption by both natural elements and human water-use. The connections between these two drought types were analyzed using the Standardized Precipitation Evapotranspiration Index (SPEI) and Standardized Streamflow Index (SSI), respectively, in a typical semi-arid basin of the middle Yellow River.

Description: 〈b〉Study on the water resources optimal operation based on riverbed wind erosion control in West Liaohe River plain〈/b〉〈br〉 Sun Wanguang, Li Chengzhen, and Fan Baoshan〈br〉 Proc. IAHS, 379, 443-453, https://doi.org/10.5194/piahs-379-443-2018, 2018〈br〉 Rivers are drying up most frequently in West Liaohe River plain and the bare river beds present fine sand belts on land. These sand belts, which yield a dust heavily in windy days, stress the local environment deeply. In this paper we establish the optimal operation model for water resources based on river desertification control. The research results show in this paper can provide technical support for the prevention and control of riverbed wind erosion in the West Liaohe River plain.

Description: 〈b〉Impact of the operation of cascade reservoirs in upper Yangtze River on hydrological variability of the mainstream〈/b〉〈br〉 Xu Changjiang and Zhang Dongdong〈br〉 Proc. IAHS, 379, 421-432, https://doi.org/10.5194/piahs-379-421-2018, 2018〈br〉 A model was established to simulate the impounding and operation of upstream cascade reservoirs so as to obtain the runoff of downstream hydrological control stations after the regulation by upstream reservoirs in different level years. The results indicated that Yichang belonged to high alteration. Xiangjiaba, Gaochang and Wulong belonged to high alteration; and Beibei belonged to medium alteration in 2010 level year, and high alteration in 2015 level year and the forward level year.

Description: 〈b〉Socio-hydrological implications of water management in the dry zone of Sri Lanka〈/b〉〈br〉 Isurun Upeksha Gamage and Hetti Arachchige Hemachandra Jayasena〈br〉 Proc. IAHS, 379, 415-420, https://doi.org/10.5194/piahs-379-415-2018, 2018〈br〉 Our research examined the sustainability of rural societies based on water usage perspectives which are different from modern societies with pipe borne water. The average daily usage for drinking, cooking, washing, toiletries, and bathing are 3, 5, 10, 7, and 85 liters per person, respectively. Majority of the families use dug wells and pipe-borne water as the primary source. Correlation coefficients suggest that higher household income or level of education leads to increased water consumption.

Description: 〈b〉Guidelines for rainwater harvesting system design and assessment for the city of Johannesburg, South Africa〈/b〉〈br〉 John Ndiritu, Adesola Ilemobade, and Paulo Kagoda〈br〉 Proc. IAHS, 379, 409-414, https://doi.org/10.5194/piahs-379-409-2018, 2018〈br〉 The research developed guidelines for determining the required tank size for rainwater harvesting (RWH) systems in the City of Johannesburg, South Africa. This research also informs how many days the system of the specified tank size would provide and how reliable this supply would be. The developed guidelines can help to assess the feasibility of RWH systems and if feasible, determine appropriate size of the storage. This way innapropriate investment decisions on RWH systems can be prevented.

Description: 〈b〉Country-level assessment of future risk of water scarcity in Europe〈/b〉〈br〉 Luis Garrote, Ana Iglesias, and Alfredo Granados〈br〉 Proc. IAHS, 379, 455-462, https://doi.org/10.5194/piahs-379-455-2018, 2018〈br〉 We present a methodology for regional assessment of current and future water availability in Europe. The methodology is based on a proposed indicator of risk of water scarcity based on the projections of runoff and water availability for European countries. The water scarcity risk index is a global value that accounts for the results obtained with the ensemble of model results and emission scenarios.

Description: 〈b〉Preface: Innovative Water Resources Management in a Changing Environment – Understanding and Balancing Interactions between Humankind and Nature〈/b〉〈br〉 Zongxue Xu, Dingzhi Peng, Wenchao Sun, Bo Pang, Depeng Zuo, Andreas Schumann, and Yangbo Chen〈br〉 Proc. IAHS, 379, 463-464, https://doi.org/10.5194/piahs-379-463-2018, 2018〈br〉

Description: Editorial: Special Issue on Water security and the food-water-energy nexus: drivers, responses and feedbacks at local to global scales Barry Croke and Graham Jewitt Proc. IAHS, 376, 1-1, https://doi.org/10.5194/piahs-376-1-2018, 2018

Description: Modelling the water energy nexus: should variability in water supply impact on decision making for future energy supply options? James D. S. Cullis, Nicholas J. Walker, Fadiel Ahjum, and Diego Juan Rodriguez Proc. IAHS, 376, 3-8, https://doi.org/10.5194/piahs-376-3-2018, 2018 This study describes a model for incorporating regional variability in water supply costs into an energy planning model and the impacts of this on the most sustainable future energy mix for a country as well as the potential impact that energy related policies can have on the future of water supply availability in different regions. Modeling of the water-energy nexus is particularly relevant as water supply becomes more variable due to climate change and a potential constraint on development.

Description: The water–food–energy nexus in Pakistan: a biophysical and socio-economic challenge Nicola Grigg, Tira Foran, Toni Darbas, Mac Kirby, Matthew J. Colloff, Mobin-ud-Din Ahmad, and Geoff Podger Proc. IAHS, 376, 9-13, https://doi.org/10.5194/piahs-376-9-2018, 2018 We draw on previous work examining likely future water use and food availability in Pakistan and extend the analysis to consider hydropower generation and energy demand in food production. The biophysical limits of the water-energy-food nexus are just one piece of the picture. We also draw on critical social science and resilience or adaptation-oriented perspectives to consider options usually deemed out of scope for biophysical scientists or water, energy and agricultural authorities.

Description: Water impacts and water-climate goal conflicts of local energy choices – notes from a Swedish perspective Rebecka Ericsdotter Engström, Mark Howells, and Georgia Destouni Proc. IAHS, 376, 25-33, https://doi.org/10.5194/piahs-376-25-2018, 2018 To meet the global goals (SDGs) on energy and climate, local communities must move towards sustainable energy systems. Our study explores the indirect water uses linked to the supply of energy in 21 counties of Sweden – the country considered to be most advanced towards meeting the SDGs. Results show that the quantity and geography of energy-related water use vary greatly between counties. Further, local inventories of CO 2 -emissions or direct water use poorly correlate with these variation.

Description: Water, energy and agricultural landuse trends at Shiroro hydropower station and environs Olubunmi Adegun, Olalekan Ajayi, Gbolahan Badru, and Shakirudeen Odunuga Proc. IAHS, 376, 35-43, https://doi.org/10.5194/piahs-376-35-2018, 2018 The study used a combination of methods to investigate the feedback mechanisms of the food-water-energy nexus of the Shiroro hydropower station and its environs. The study shows that while there is a general decline in rainfall, coupled with low level of reservoir reliability, the area of agricultural landsue around the dam has increased significantly. In view of these realities, the study recommends that a roadmap to improve the operational coordination and management of the dam be put in place.

Description: An integrated approach to improving rural livelihoods: examples from India and Bangladesh Barry Croke, Wendy Merritt, Peter Cornish, Geoffrey J. Syme, and Christian H. Roth Proc. IAHS, 376, 45-50, https://doi.org/10.5194/piahs-376-45-2018, 2018 Water and food security are vital for improving livelihoods in disadvantaged rural areas. Understanding the water cycle is central to the design of watershed development works intended to improve water security. Better farming practices can help improve food security. It is also vital for social constraints and equity to be considered. Finally, a participatory learning approach is useful for ensuring that watershed development work is effective in producing long-term improvement in livelihoods.

Description: Supporting better decisions across the nexus of water, energy and food through earth observation data: case of the Zambezi basin Fortune Faith Gomo, Christopher Macleod, John Rowan, Jagadeesh Yeluripati, and Kairsty Topp Proc. IAHS, 376, 15-23, https://doi.org/10.5194/piahs-376-15-2018, 2018 The water–energy–food (WEF) nexus has been promoted in recent years as an intersectional concept designed to improve planning and regulatory decision-making across the three sectors. The production and consumption of water, energy and food resources are inextricably linked across multiple spatial scales (from the global to the local), but a common feature is competition for land which through different land management practices mediates provisioning ecosystem services. The nexus perspective seeks to understand the interlinkages and use systems-based thinking to frame management options for the present and the future. It aims to highlight advantage and minimise damaging and unsustainable outcomes through informed decisions regarding trade-offs inclusive of economic, ecological and equity considerations. Operationalizing the WEF approach is difficult because of the lack of complete data, knowledge and observability – and the nature of the challenge also depends on the scale of the investigation. Transboundary river basins are particularly challenging because whilst the basin unit defines the hydrological system this is not necessarily coincident with flows of food and energy. There are multiple national jurisdictions and geopolitical relations to consider. Land use changes have a profound influence on hydrological, agricultural, energy provisioning and regulating ecosystem services. Future policy decisions in the water, energy and food sectors could have profound effects, with different demands for land and water resources, intensifying competition for these resources in the future. In this study, we used Google Earth Engine (GEE) to analyse the land cover changes in the Zambezi river basin (1.4 million km 2 ) from 1992 to 2015 using the European Space Agency annual global land cover dataset. Early results indicate transformative processes are underway with significant shifts from tree cover to cropland, with a 4.6 % loss in tree cover and a 16 % gain in cropland during the study period. The changes were found to be occurring mainly in the eastern (Malawi and Mozambique) and southern (Zimbabwe and southern Zambia) parts of the basin. The area under urban land uses was found to have more than doubled during the study period gearing urban centres increasingly as the foci for resource consumption. These preliminary findings are the first step in understanding the spatial and temporal interlinkages of water, energy and food by providing reliable and consistent evidence spanning the local, regional, national and whole transboundary basin scale.

Description: A half-baked solution: drivers of water crises in Mexico Jonatan Godinez Madrigal, Pieter van der Zaag, and Nora van Cauwenbergh Proc. IAHS, 376, 57-62, https://doi.org/10.5194/piahs-376-57-2018, 2018 A part of the population of Mexico is undergoing severe water crises vis-a-vis with the quantity and quality of water. The water authority's strategy dwells solely in infrastructure development to tackle the symptoms, not the causes. The paper summarizes how the causes of crises lie not in the lack of infrastructure but in a deficient management and governance. I did the research because I'd to influence on policy, and I did it through fieldwork and critical literature review.

Description: Forecasting domestic water demand in the Haihe river basin under changing environment Xiao-Jun Wang, Jian-Yun Zhang, Shamsuddin Shahid, Yu-Xuan Xie, and Xu Zhang Proc. IAHS, 376, 51-55, https://doi.org/10.5194/piahs-376-51-2018, 2018 A statistical model has been developed for forecasting domestic water demand in Haihe river basin of China due to population growth, technological advances and climate change. Historical records of domestic water use, climate, population and urbanization are used for the development of model. An ensemble of seven general circulation models (GCMs) namely, BCC-CSM1-1, BNU-ESM, CNRM-CM5, GISS-E2-R, MIROC-ESM, PI-ESM-LR, MRI-CGCM3 were used for the projection of climate and the changes in water demand.

Description: Land susceptibility to soil erosion in Orashi Catchment, Nnewi South, Anambra State, Nigeria Shakirudeen Odunuga, Abiodun Ajijola, Nkechi Igwetu, and Olubunmi Adegun Proc. IAHS, 376, 87-95, https://doi.org/10.5194/piahs-376-87-2018, 2018 Soil erosion susceptibility analysis was based on rainfall, Land use, slope and soil erodibility factor. GIS was used to produce the basin susceptibility to soil erosion using weight index of each factors. The results revealed that 106.66 km 2 (25.70 %) and 164.80 km 2 (39.7 %) of the basin have high and very high susceptibility to soil erosion. The over 50 % high susceptibility of catchment area has negative implications on ecosystem services of the s stream.

Description: Potential impact of climate change to the future streamflow of Yellow River Basin based on CMIP5 data Xiaoli Yang, Weifei Zheng, Liliang Ren, Mengru Zhang, Yuqian Wang, Yi Liu, Fei Yuan, and Shanhu Jiang Proc. IAHS, 376, 97-104, https://doi.org/10.5194/piahs-376-97-2018, 2018 The Yellow River Basin (YRB) is the largest river basin in northern China, which has suffering water scarcity and drought hazard for many years. Therefore, assessments the potential impacts of climate change on the future streamflow in this basin is very important for local policy and planning on food security. In this study, based on the observations of 101 meteorological stations in YRB, equidistant CDF matching (EDCDFm) statistical downscaling approach was applied to eight climate models under two emissions scenarios (RCP4.5 and RCP8.5) from phase five of the Coupled Model Intercomparison Project (CMIP5). Variable infiltration capacity (VIC) model with 0.25°  ×  0.25° spatial resolution was developed based on downscaled fields for simulating streamflow in the future period over YRB. The results show that with the global warming trend, the annual streamflow will reduced about 10 % during the period of 2021–2050, compared to the base period of 1961–1990 in YRB. There should be suitable water resources planning to meet the demands of growing populations and future climate changing in this region.

Description: Conceptual framework to ensure water security in Ukraine Yaroslav Gadzalo, Mykhailo Romashchenko, and Mykhailo Yatsiuk Proc. IAHS, 376, 63-68, https://doi.org/10.5194/piahs-376-63-2018, 2018 As a result of global climate change nowadays Ukraine is facing the problem of environmental degradation of river basins. Thus, achieving an acceptable level of water security in Ukraine should be defined as the strategic objective of national water policy. The basic principles of a new water policy are supposed to be represented in Water Strategy of Ukraine. Integrated water management by the basin principle should serve as a main tool for achieving the objectives of country's water security.

Description: Performance assessment of the Gash Delta Spate Irrigation System, Sudan Araya Z. Ghebreamlak, Haruya Tanakamaru, Akio Tada, Bashir M. Ahmed Adam, and Khalid A. E. Elamin Proc. IAHS, 376, 69-75, https://doi.org/10.5194/piahs-376-69-2018, 2018 The Gash Delta Spate Irrigation System (GDSIS), located in eastern Sudan with a net command area of 100 000 ha (an area currently equipped with irrigation structures), was established in 1924. The land is irrigated every 3 years (3-year rotation) or every 2 years (2-year rotation) so that about 33 000 or 50 000 ha respectively can be cultivated annually. This study deals with assessing the performance of the 3- and 2-year rotation systems using the Monte Carlo simulation. Reliability, which is a measure of how frequently the irrigation water supply satisfies the demand, and vulnerability, which is a measure of the magnitude of failure, were selected as the performance criteria. Combinations of five levels of intake ratio and five levels of irrigation efficiency for the irrigation water supply of each rotation system were analysed. Historical annual flow data of the Gash River for 107 years were fit to several frequency distributions. The Weibull distribution was the best on the basis of the Akaike information criteria and was used for simulating the ensembles of annual river flow. The reliabilities and vulnerabilities of both rotation systems were evaluated at typical values of intake ratio and irrigation efficiency. The results show that (i) the 3-year rotation is more reliable in water supply than the 2-year rotation, (ii) the vulnerability of the 3-year rotation is lower than that of the 2-year rotation and (iii) therefore the 3-year rotation is preferable in the GDSIS. The sensitivities of reliability and vulnerability to changes in intake ratio and irrigation efficiency were also examined.

Description: Socio-Hydrological Approach to the Evaluation of Global Fertilizer Substitution by Sustainable Struvite Precipitants from Wastewater Dirk-Jan Daniel Kok, Saket Pande, Angela Renata Cordeiro Ortigara, Hubert Savenije, and Stefan Uhlenbrook Proc. IAHS, 376, 83-86, https://doi.org/10.5194/piahs-376-83-2018, 2018 Phosphorus is necessary for the development of crops and is therefore essential in safeguarding our food security. Several studies predict that our rock phosphate reserves, used to create synthetic, phosphatic fertilizers, may become depleted within this century. This study roughly approximates for which areas in Africa we can instead recover phosphorus from wastewater in order to reduce our dependancy on unsustainable rock phosphate.

Description: Modelling the impact of mulching the soil with plant remains on water regime formation, crop yield and energy costs in agricultural ecosystems Yeugeniy M. Gusev, Larisa Y. Dzhogan, and Olga N. Nasonova Proc. IAHS, 376, 77-82, https://doi.org/10.5194/piahs-376-77-2018, 2018 It is shown that in agriculture technologies soil mulching with plant remains leads to increase in the ratio of actual transpiration to potential one and to increase in the yield of crops. Soil mulching with plant remains in combination with subsurface cultivation is the most efficient agricultural mode for the regions of the steppe and forest-steppe zones of the East-European (Russian) plain. This technology is most promising for development of agriculture in these regions.

Description: Recent sedimentary and morphological changes at the new mouth of Medjerda-River (Gulf of Tunis) are investigated using a multiproxy approach of sediment cores complited by 210Pbex and 137Cs method dating. The subject of the study is to focus on surveying the sedimentary evolution of Medjerda-Raoued Delta caused by the human intervention in the management of the main tributaries of the Medjerda-River (artificial channel of Henchir Tobias). Sediment cores (CEM-1 and CEM-3) were subjected to both multiproxy approaches (Grain size, geochemical analysis and dating radiometric 210Pbex and 137Cs). The sedimentological analysis of the new deltaic deposits shows a progradation sequence with the silt and clay deposits on the historic sandy substratum. The mean grain size evolution on the old beach profile shows a decreasing trend from backshore (CEM-3) to nearshore (CEM-1). The geochemical results show varying concentrations of chemical elements such as Fe, K, Rb, Nb, Cr, Ti, Ba, Ca, Sr, Zr, V, and potentially toxic metal trace elements such as Pb, Zn and the As. The Principal component Analysis (PCA) applied in the geochemical elements evolution confirms the marine origin of the sand deposits in the basic layers of the two cores. The chronological method (210Pbex and 137Cs) affirms that the first fluvial deposits were set up only after 1950. The sedimentological and geochemical result confirm the actual unless of coarser fluvial supplies under the human activities leading the negative coastal sediment balance and the shoreline retreat as well.

Description: Soil erosion has detrimental impacts on socio economic life, thus increasing poverty. This situation is aggravated by poor planning and lack of infrastructure especially in developing countries. In these countries, efforts to planning are challenged by lack of data. Alternative approaches that use remote sensing and geographical information systems are therefore needed to provide decision makers with the so much needed information for planning purposes. This helps to curb the detrimental impacts of soil erosion, mostly emanating from varied land use conditions. This study was carried out in the city of Kinshasa, the Democratic Republic of Congo with the aim of using alternative sources of data, based on earth observation resources, to determine the spatial distribution of soil loss and erosion hazard in the city of Kinshasa. A combined approach based on remote sensing skills and rational equation of soil erosion estimation was used. Soil erosion factors, including rainfall-runoff erosivity R), soil erodibility (K), slope steepness and length (SL), crop/vegetation and management (C) were calculated for the city of Kinshasa. Results show that soil loss in Kinshasa ranges from 0 to 20 t ha−1 yr−1. Most of the south part of the urban area were prone to erosion. From the total area of Kinshasa (996 500 ha), 25 013 ha (2.3 %) is of very high ( 〉  15 t ha−1 yr−1) risk of soil erosion. Urban areas consist of 4.3 % of the area with very high ( 〉  15 t ha−1 yr−1) risk of soil erosion compared to a very high risk of 2.3 % ( 〉  15 t ha−1 yr−1) in the rural area. The study shows that the soil loss in the study area is mostly driven by slope, elevation, and informal settlements.

Description: We analyzed changes in water quantity and quality at different spatial scales within the Tapajós River basin (Amazon) based on experimental fieldwork, hydrological modelling, and statistical time-trend analysis. At a small scale, we compared the river discharge (Q) and suspended-sediment concentrations (SSC) of two adjacent micro-catchments (

Description: The estimation of soil loss and sediment transport is important for effective management of catchments. A model for semi-arid catchments in southern Africa has been developed; however, simplification of the model parameters and further testing are required. Soil loss is calculated through the Modified Universal Soil Loss Equation (MUSLE). The aims of the current study were to: (1) regionalise the MUSLE erodibility factors and; (2) perform a sensitivity analysis and validate the soil loss outputs against independently-estimated measures. The regionalisation was developed using Geographic Information Systems (GIS) coverages. The model was applied to a high erosion semi-arid region in the Eastern Cape, South Africa. Sensitivity analysis indicated model outputs to be more sensitive to the vegetation cover factor. The simulated soil loss estimates of 40 t ha−1 yr−1 were within the range of estimates by previous studies. The outcome of the present research is a framework for parameter estimation for the MUSLE through regionalisation. This is part of the ongoing development of a model which can estimate soil loss and sediment delivery at broad spatial and temporal scales.

Description: Zimbabwe's water resources are under pressure from both point and non-point sources of pollution hence the need for regular and synoptic assessment. In-situ and laboratory based methods of water quality monitoring are point based and do not provide a synoptic coverage of the lakes. This paper presents novel methods for retrieving water quality parameters in Chivero and Manyame lakes, Zimbabwe, from remotely sensed imagery. Remotely sensed derived water quality parameters are further validated using in-situ data. It also presents an application for automated retrieval of those parameters developed in VB6, as well as a web portal for disseminating the water quality information to relevant stakeholders. The web portal is developed, using Geoserver, open layers and HTML. Results show the spatial variation of water quality and an automated remote sensing and GIS system with a web front end to disseminate water quality information.

Description: Lakes play important roles in the economic-social sustainable development. However, due to unreasonable development and urbanization in recent years, lake water pollution and ecological degradation have occurred in China. The improvement of the lake inflow water quality is very important. A filtration system includes Gravel filtering system, Aquatic plant area and Ecological bag area was established. The test river is one of the typical lake inflow river and located in the river network in the Chang Dang lake, China. Water quality, zooplankton and phytoplankton in the inflow river were observed form July to mid-August in order to analyze the general process. The average removal rate of NH3-N (ammonia nitrogen) TN (total nitrogen) and TP (total phosphorus) is 28.33, 25.76 and 24.43 %, respectively. The Pantle-Buck method was used to evaluate the water quality and the B∕T index was used to evaluate the nutrition situation. The B∕T values were reduced by 20 % and the SI pollution index was reduced by 11.8 %. Therefore, a positive effect on the water's ecological restoration was achieved by the filtration system.

Description: Land use changes alter the hydrological characteristics of the land surface, and have significant impacts on hydrological cycle and water balance, the analysis of complex effects on natural systems has become one of the main concerns. In this study, we generated the land use conversion matrixes using ArcGIS and selected several landscape indexes (contagion index, CONTAG, Shannon's diversity index, SHDI, etc.) to evaluate the impact of land use/cover changes on hydrological process in the upper reaches of Minjiang River. We also used a statistical regression model which was established based on hydrology and precipitation data during the period of 1959–2008 to simulate the impacts of different land use conditions on rainfall and runoff in different periods. Our results showed that the simulated annual mean flow from 1985 to 1995 and 1995 to 2008 are 9.19 and 1.04 m3 s−1 lower than the measured values, respectively, which implied that the ecological protection measures should be strengthened in the study area. Our study could provide a scientific basis for water resource management and proper land use planning of upper reaches of Minjiang River.

Description: With the aggravation of the global climate change, the shortage of water resources in China is becoming more and more serious. Using reasonable methods to study changes in precipitation is very important for planning and management of water resources. Based on the time series of precipitation in Beijing from 1951 to 2015, the multi-scale features of precipitation are analyzed by the Extreme-point Symmetric Mode Decomposition (ESMD) method to forecast the precipitation shift. The results show that the precipitation series have periodic changes of 2.6, 4.3, 14 and 21.7 years, and the variance contribution rate of each modal component shows that the inter-annual variation dominates the precipitation in Beijing. It is predicted that precipitation in Beijing will continue to decrease in the near future.

Description: Socio-hydrological modelling studies that have been published so far show that dynamic coupled human-flood models are a promising tool to represent the phenomena and the feedbacks in human-flood systems. So far these models are mostly generic and have not been developed and calibrated to represent specific case studies. We believe that applying and calibrating these type of models to real world case studies can help us to further develop our understanding about the phenomena that occur in these systems. In this paper we propose a method to estimate the parameter values of a socio-hydrological model and we test it by applying it to an artificial case study. We postulate a model that describes the feedbacks between floods, awareness and preparedness. After simulating hypothetical time series with a given combination of parameters, we sample few data points for our variables and try to estimate the parameters given these data points using Bayesian Inference. The results show that, if we are able to collect data for our case study, we would, in theory, be able to estimate the parameter values for our socio-hydrological flood model.

Description: Hydrological models are important and effective tools for detecting complex hydrological processes. Different models have different strengths when capturing the various aspects of hydrological processes. Relying on a single model usually leads to simulation uncertainties. Ensemble approaches, based on multi-model hydrological simulations, can improve application performance over single models. In this study, the upper Yalongjiang River Basin was selected for a case study. Three commonly used hydrological models (SWAT, VIC, and BTOPMC) were selected and used for independent simulations with the same input and initial values. Then, the BP neural network method was employed to combine the results from the three models. The results show that the accuracy of BP ensemble simulation is better than that of the single models.

Description: The water-food-energy-GHG nexus under climate change has been gaining increasing attention from both the research and policy communities, especially over the past several years. However, most existing nexus studies are qualitative and explorative in nature. So far, very few studies provide integrated analysis of this nexus across all the four sectors. The purpose of this paper is to examine this nexus by assessing the effects of climate change on agricultural production through the change in water availability, evaluating the adjustment responses and resulting energy consumption and GHG emission, with the Northeast China as a case study. Based on our simulation results, by 2030, climate change is projected to increase water supply and demand gap for irrigation in Northeast China. Due to the increase in water scarcity, irrigated areas will decrease, and the cropping pattern will be adjusted by increasing maize sown areas and decreasing rice sown areas. As a result, the total output of crops and profits will clearly be reduced. Finally, energy consumption and GHG emission from irrigation will be reduced. This study suggests that climate change impact assessment fully consider the nexus among water, food, energy and GHG; however, more studies need to be conducted in the future.

Description: The temporal and spatial variations of drought in the Wei River basin (WRB) were investigated by calculating the meteorological drought Index (Standardized Precipitation Index, SPI) and the agricultural drought index (Vegetation Health Index, VHI). Monthly precipitation and air temperature were from 22 meteorological stations over the region from 1960 to 2015. Monthly Normalized Difference Vegetation Index (NDVI) and 8-days Land Surface Temperature (LST) were provided from the National Aeronautics and Space Administration (NASA) for the period 2000–2015 were also adopted. The results showed that the drought initially increased and then decreased, reaching at the maximum value in 1990s. The spatial pattern of meteorological drought showed that the drought in northern WRB was heavier than that in southern WRB before 1990s, after that, the situation had the opposite. By comparing the agricultural drought index (VHI) with crop yield, it was proved that VHI was applicable in the WRB and could well reflect the fluctuation of agricultural drought. The WRB suffered from serious agricultural drought in 2000, 2001, 2007 and 2008. Through analysis of the historical precipitation and temperature data, it was found that precipitation had a greater contribution to creating agricultural drought conditions than temperature in the Wei River basin.

Description: Perchlorate (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects and widespread occurrence in surface water and groundwater. Analyses carried out in France have highlighted the presence of ClO4- in drinking water of Champagne-Ardenne (NW of France), with two potential sources suspected: a military source related to the First World War and an agricultural source related to the past use of Chilean nitrates. To determine the sources of ClO4- in groundwater, major and trace elements, 2H and 18O, ClO3- and ClO4- ions and a list of 39 explosives were analyzed from 35 surface water and groundwater sampling points in the east of the city of Reims. ClO4- ions were found in almost all sampling points (32 out of 35) with a max value of 33 µg L−1. ClO4- concentrations were highest in groundwater ranging from 0.7 to 33 µg L−1 (average value of about 6.2 µg L−1) against from  4 µg L−1) were collected near a military camp, where huge quantities of ammunitions have been used, stored and destroyed during and after the First World War.

Description: The time-varying design flood can make full use of the measured data, which can provide the reservoir with the basis of both flood control and operation scheduling. This paper adopts peak over threshold method for flood sampling in unit periods and Poisson process with time-dependent parameters model for simulation of reservoirs time-varying design flood. Considering the relationship between the model parameters and hypothesis, this paper presents the over-threshold intensity, the fitting degree of Poisson distribution and the design flood parameters are the time-varying design flood unit period and threshold discriminant basis, deduced Longyangxia reservoir time-varying design flood process at 9 kinds of design frequencies. The time-varying design flood of inflow is closer to the reservoir actual inflow conditions, which can be used to adjust the operating water level in flood season and make plans for resource utilization of flood in the basin.

Description: Recently, the water disaster in cities especially in Chinese mountainous cities is more serious, due to the coupling influences of waterlogging and regional floods. It is necessary to study the surface runoff process of mountainous cities and examine the regional drainage pipeline network. In this study, the runoff processes of Lincheng county (located in Hebei province, China) in different scenarios were simulated through Mike Urban model. The results show that all of the runoff process of the old town and the new residential area with larger slope, is significant and full flow of these above zones exists in the part of the drainage pipeline network; and the overflow exists in part of the drainage pipeline network when the return period is ten years or twenty years, which illuminates that the waterlogging risk in this zone of Lincheng is higher. Therefore, remodeling drainage pipeline network in the old town of Lincheng and adding water storage ponds in the new residential areas were suggested. This research provides both technical support and decision-making reference to local storm flood management, also give the experiences for the study on the runoff process of similar cities.

Description: The control of sedimentation in a reservoir provides a global evaluation of the process of erosion and transportation of sediment. Knowledge of sedimentation is useful for reservoir management. Bathymetric surveys can be used to assess the silting volume of dams. The results of two surveys of the Ghézala dam reservoir in northern Tunisia are available. The measurements provide initial information about the quantity and variability of silting and the mechanism of sediment deposition. According to the results of measurements, the average annual specific sediment yield of the Ghézala dam watershed is estimated at 1851 tkm-2yr-1. The annual average sediment volume trapped varies from 23 000 m3 in 1993 to 66 692 m3 in 2011. The sedimentation rates increases from 0.20 to 0.57 % overtime. The results indicate interdependence between the specific erosion rates and the occurrence of soils on steep slopes. The pressure exerted on the soil by plowing as well as overgrazing to meet the needs of the population of this area has exposed the soil to continued deterioration manifested by increased erosion endangering the only source of revenue for the area.

Description: The continuous decline in water quality in many regions is forcing a shift from quantity-based water resources management to a greater emphasis on water quality management. Water quality models can act as invaluable tools as they facilitate a conceptual understanding of processes affecting water quality and can be used to investigate the water quality consequences of management scenarios. In South Africa, the Water Quality Systems Assessment Model (WQSAM) was developed as a management-focussed water quality model that is relatively simple to be able to utilise the small amount of available observed data. Importantly, WQSAM explicitly links to systems (yield) models routinely used in water resources management in South Africa by using their flow output to drive water quality simulations. Although WQSAM has been shown to be able to represent the variability of water quality in South African rivers, its focus on management from a South African perspective limits its use to within southern African regions for which specific systems model setups exist. Facilitating the use of WQSAM within catchments outside of southern Africa and within catchments for which these systems model setups to not exist would require WQSAM to be able to link to a simple-to-use and internationally-applied systems model. One such systems model is the Water Evaluation and Planning (WEAP) model, which incorporates a rainfall-runoff component (natural hydrology), and reservoir storage, return flows and abstractions (systems modelling), but within which water quality modelling facilities are rudimentary. The aims of the current study were therefore to: (1) adapt the WQSAM model to be able to use as input the flow outputs of the WEAP model and; (2) provide an initial assessment of how successful this linkage was by application of the WEAP and WQSAM models to the Buffalo River for historical conditions; a small, semi-arid and impacted catchment in the Eastern Cape of South Africa. The simulations of the two models were compared to the available observed data, with the initial focus within WQSAM on a simulation of instream total dissolved solids (TDS) and nutrient concentrations. The WEAP model was able to adequately simulate flow in the Buffalo River catchment, with consideration of human inputs and outputs. WQSAM was adapted to successfully take as input the flow output of the WEAP model, and the simulations of nutrients by WQSAM provided a good representation of the variability of observed nutrient concentrations in the catchment. This study showed that the WQSAM model is able to accept flow inputs from the WEAP model, and that this approach is able to provide satisfactory estimates of both flow and water quality for a small, semi-arid and impacted catchment. It is hoped that this research will encourage the application of WQSAM to an increased number of catchments within southern Africa and beyond.

Description: Sediment delivery into water sources and bodies results in the reduction of water quantity and quality, increasing costs of water purification whilst reducing the available water for various other uses. The paper gives an analysis of sedimentation in one of Zimbabwe's seven rivers, the Mazowe Catchment, and its impact on water quality. The Revised Universal Soil Loss Equation (RUSLE) model was used to compute soil lost from the catchment as a result of soil erosion. The model was used in conjunction with GIS remotely sensed data and limited ground observations. The estimated annual soil loss in the catchment indicates soil loss ranging from 0 to 65 t ha yr−1. Bathymetric survey at Chimhanda Dam showed that the capacity of the dam had reduced by 39 % as a result of sedimentation and the annual sediment deposition into Chimhanda Dam was estimated to be 330 t with a specific yield of 226 t km−2 yr−1. Relationship between selected water quality parameters, TSS, DO, NO3, pH, TDS, turbidity and sediment yield for selected water sampling points and Chimhanda Dam was analyzed. It was established that there is a strong positive relationship between the sediment yield and the water quality parameters. Sediment yield showed high positive correlation with turbidity (0.63) and TDS (0.64). Water quality data from Chimhanda treatment plant water works revealed that the quality of water is deteriorating as a result of increase in sediment accumulation in the dam. The study concluded that sedimentation can affect the water quality of water sources.

Description: The sedimentary contributions of the Medjerda to the coastal zone are poorly measured, and there is no chronicle of observations. In this context, the sediment monitoring appears indispensable for the quantification of sediment transport at the outlet. This study focuses on the largest watershed in Tunisia, the Wadi Medjerda (23 600 km2). The main objective of this work is to assess the reduction of sediment transport following anthropogenic intensification on the basin, especially since the construction of many large dams. In order to collect information on actual deposits over several years, the paleo-hydrological approach was applied through the study of sediment cores sampled in the low valley meanders on alluvial terraces, after the last dam (Sidi Salem, the largest water storage capacity over the basin), but before the estuary to avoid marine influence and near a hydrological station (Jdaida). The sedimentary deposits of the river provide key information on the past sedimentary inputs. A visible succession of sedimentary layers corresponding to the deposits of successive floods on the study site has been determined and the history of the sedimentary contributions of the Medjerda is reconstructed by this approach. The thickest layers of sedimentary deposits are related to exceptional events. They are mainly concentrated on the lower part of the core and are mainly composed of sands. The first 1.2 m of the core from the bottom upward relates to 10 years of river discharges, as can be determined from the 137Cs datation. The next upward 1.05 m of core relates to the following 20 years of discharges, up to 1981, date of the construction of the Sidi Salem dam, and is composed of a mix of sand, silts and clays. The last 75 cm of core near the surface is only composed of clays with thin silt bands, and relates to a period of 32 years. We thus observe that there is no more sand deposits in the river bed since the construction of the Sidi Salem dam. The deficit of sediment supply to the sea is viewed as a major factor to be taken into account for better understanding of the dynamics of coastal areas in the context of global climate change.

Description: We investigate the impacts of land cover changes on the river flows of the Middle Zambezi tributary catchments in Zimbabwe. Trend analysis on rainfall and streamflow was carried out using the Mann-Kendall test at monthly and annual time steps. Rainfall analysis indicated an increasing trend which was not statistically significant (p

Description: Water availability is one of the major societal issues facing the world. The ability to understand and quantify the impact of key hydrological processes, on the availability of water resources, is therefore integral to ensuring equitable and sustainable resource management. Channel transmission losses are an “under-researched” hydrological process that affects resource availability in many semi-arid regions such as the Limpopo River Basin in southern Africa, where the loss processes amount to approximately 30 % of the water balance. To improve the understanding of these loss processes and test the capability of modelling routines, three approaches using the Pitman model are applied to selected alluvial aquifer environments. The three approaches are an explicit transmission loss function, the use of a wetland function to represent channel-floodplain storage exchanges and the use of a “dummy” reservoir to represent floodplain storage and evapotranspiration losses. Results indicate that all three approaches are able to simulate channel transmission losses with differing impacts on the regional flows. A determination of which method best represents the channel transmission losses process requires further testing in a study area that has reliable observed historical records.

Description: Flash floods are experienced almost annually in the ungauged Mbire District of the Middle Zambezi Basin. Studies related to hydrological modelling (rainfall-runoff) and flood forecasting require major inputs such as precipitation which, due to shortage of observed data, are increasingly using indirect methods for estimating precipitation. This study therefore evaluated performance of CMORPH and TRMM satellite rainfall estimates (SREs) for 30 min, 1 h, 3 h and daily intensities through hydrologic and flash flood modelling in the Lower Middle Zambezi Basin for the period 2013–2016. On a daily timestep, uncorrected CMORPH and TRMM show Probability of Detection (POD) of 61 and 59 %, respectively, when compared to rain gauge observations. The best performance using Correlation Coefficient (CC) was 70 and 60 % on daily timesteps for CMORPH and TRMM, respectively. The best RMSE for CMORPH was 0.81 % for 30 min timestep and for TRMM was 2, 11 % on 3 h timestep. For the year 2014 to 2015, the HEC-HMS (Hydrological Engineering Centre-Hydrological Modelling System) daily model calibration Nash Sutcliffe efficiency (NSE) for Musengezi sub catchment was 59 % whilst for Angwa it was 55 %. Angwa sub-catchment daily NSE results for the period 2015–2016 was 61 %. HEC-RAS flash flood modeling at 100, 50 and 25 year return periods for Angwa sub catchment, inundated 811 and 867 ha for TRMM rainfall simulated discharge at 3 h and daily timesteps, respectively. For CMORPH generated rainfall, the inundation was 818, 876, 890 and 891 ha at daily, 3 h, 1 h and 30 min timesteps. The 30 min time step for CMORPH effectively captures flash floods with the measure of agreement between simulated flood extent and ground control points of 69 %. For TRMM, the 3 h timestep effectively captures flash floods with coefficient of 67 %. The study therefore concludes that satellite products are most effective in capturing localized hydrological processes such as flash floods for sub-daily rainfall, because of improved spatial and temporal resolution.

Description: The management and allocation of water from multi-reservoir systems is complex and thus requires dynamic modelling systems to achieve optimality. A multi-reservoir system in the Southern Lowveld of Zimbabwe is used for irrigation of sugarcane estates that produce sugar for both local and export consumption. The system is burdened with water allocation problems, made worse by decommissioning of dams. Thus the aim of this research was to develop an operating policy model for the Lowveld multi-reservoir system.The Mann Kendall Trend and Wilcoxon Signed-Rank tests were used to assess the variability of historic monthly rainfall and dam inflows for the period 1899–2015. The WEAP model was set up to evaluate the water allocation system of the catchment and come-up with a reference scenario for the 2015/2016 hydrologic year. Stochastic Dynamic Programming approach was used for optimisation of the multi-reservoirs releases.Results showed no significant trend in the rainfall but a significantly decreasing trend in inflows (p 

Description: Though extensive researches were conducted in the source region of the Yellow River (SRYR) to analyse climate change influence on streamflow, however, few researches concentrate on streamflow of the sub-basin above the Huangheyan station in the SRYR (HSRYR) where a water retaining dam was built in the outlet in 1999. To improve the reservoir regulation strategies, this study analysed streamflow change of the HSRYR in a mesoscale. A tank model (TM) was proposed and calibrated with monthly observation streamflow from 1991 to 1998. In the validation period, though there is a simulation deviation during the water storage and power generation period, simulated streamflow agrees favourably with observation data from 2008 to 2013. The model was further validated by two inside lakes area obtained from Landsat 5, 7, 8 datasets from 2000 to 2014, and significant correlations were found between the simulated lake outlet runoff and respective lake area. Then 21 Global Climate Models (GCM) ensembled data of three emission scenarios (SRA2, SRA1B and SRB1) were downscaled and used as input to the TM to simulate the runoff change of three benchmark periods 2011–2030 (2020s), 2046–2065 (2050s), 2080–2099 (2090s), respectively. Though temperature increase dramatically, these projected results similarly indicated that streamflow shows an increase trend in the long term. Runoff increase is mainly caused by increasing precipitation and decreasing evaporation. Water resources distribution is projected to change from summer-autumn dominant to autumn winter dominant. Annual lowest runoff will occur in May caused by earlier snow melting and increasing evaporation in March. According to the obtained results, winter runoff should be artificially stored by reservoir regulation in the future to prevent zero-flow occurrent in May. This research is helpful for water resources management and provides a better understand of streamflow change caused by climate change in the future.

Description: Management of water resources requires understanding of the hydrology and hydrogeology, as well as the policy and human drivers and their impacts. This understanding requires relevant inputs from a wide range of disciplines, which will vary depending on the specific case study. One approach to gain understanding of the impact of climate and society on water resources is through the use of an integrated modelling process that engages stakeholders and experts in specifics of problem framing, co-design of the underpinning conceptual model, and discussion of the ensuing results. In this study, we have developed such an integrated modelling process for the Campaspe basin in northern Victoria, Australia. The numerical model built has a number of components: Node/link based surface water hydrology module based on the IHACRES rainfall-streamflow model Distributed groundwater model for the lower catchment (MODFLOW) Farm decision optimisation module (to determine irrigation requirements) Policy module (setting conditions on availability of water based on existing rules) Ecology module (determining the impacts of available streamflow on platypus, fish and river red gum trees) The integrated model is component based and has been developed in Python, with the MODFLOW and surface water hydrology model run in external programs, controlled by the master program (in Python). The integrated model has been calibrated using historical data, with the intention of exploring the impact of various scenarios (future climate scenarios, different policy options, water management options) on the water resources. The scenarios were selected based on workshops with, and a social survey of, stakeholders in the basin regarding what would be socially acceptable and physically plausible options for changes in management. An example of such a change is the introduction of a managed aquifer recharge system to capture dam overflows, and store at least a portion of this in the aquifer, thereby increasing the groundwater resource as well as reducing the impact of existing pumping levels.

Description: The demand for water resources is rapidly growing, placing more strain on access to water and its management. In order to appropriately manage water resources, there is a need to accurately quantify available water resources. Unfortunately, the data required for such assessment are frequently far from sufficient in terms of availability and quality, especially in southern Africa. In this study, the uncertainty related to the estimation of water resources of two sub-basins of the Limpopo River Basin – the Mogalakwena in South Africa and the Shashe shared between Botswana and Zimbabwe – is assessed. Input data (and model parameters) are significant sources of uncertainty that should be quantified. In southern Africa water use data are among the most unreliable sources of model input data because available databases generally consist of only licensed information and actual use is generally unknown. The study assesses how these uncertainties impact the estimation of surface water resources of the sub-basins. Data on farm reservoirs and irrigated areas from various sources were collected and used to run the model. Many farm dams and large irrigation areas are located in the upper parts of the Mogalakwena sub-basin. Results indicate that water use uncertainty is small. Nevertheless, the medium to low flows are clearly impacted. The simulated mean monthly flows at the outlet of the Mogalakwena sub-basin were between 22.62 and 24.68 Mm3 per month when incorporating only the uncertainty related to the main physical runoff generating parameters. The range of total predictive uncertainty of the model increased to between 22.15 and 24.99 Mm3 when water use data such as small farm and large reservoirs and irrigation were included. For the Shashe sub-basin incorporating only uncertainty related to the main runoff parameters resulted in mean monthly flows between 11.66 and 14.54 Mm3. The range of predictive uncertainty changed to between 11.66 and 17.72 Mm3 after the uncertainty in water use information was added.

Description: Sediment and runoff changes of seven hydrological stations along the Lower Yellow River (LYR) (Huayuankou Station, Jiahetan Station, Gaocun Station, Sunkou Station, Ai Shan Station, Qikou Station and Lijin Station) from 1980 to 2003 were alanyzed at multiple time scale. The maximum value of monthly, daily and hourly sediment load and runoff conservations were also analyzed with the annually mean value. Mann–Kendall non-parametric mathematics correlation test and Hurst coefficient method were adopted in the study. Research results indicate that (1) the runoff of seven hydrological stations was significantly reduced in the study period at different time scales. However, the trends of sediment load in these stations were not obvious. The sediment load of Huayuankou, Jiahetan and Aishan stations even slightly increased with the runoff decrease. (2) The trends of the sediment load with different time scale showed differences at Luokou and Lijin stations. Although the annually and monthly sediment load were broadly flat, the maximum hourly sediment load showed decrease trend. (3) According to the Hurst coefficients, the trend of sediment and runoff will be continue without taking measures, which proved the necessary of runoff-sediment regulation scheme.

Description: Dams construction and operations have many benefits, nevertheless, they have also led to lots of negative social, health and human impacts. It is based on this that this study assesses the potential and socio-economics dynamics of Oyan dam between 1980 and 2016. The data used for this study include water level and discharge records of the dam between 2007 and 2016, Landsat imageries of 1984 and 2016 and socio-economic datasets for the period. Analysis of the dam potentials (water supply, agriculture and hydropower) and socio-economic impacts of the dam were carried out using basic statistical tools, land use change anaysis and field survey using questionnaire, structured interview with major stakeholders and personal observation. The results revealed that the water level and storage of the Oyan dam had a relative reduction of about 2 % as well as non-stationarity pattern of water abstraction and production for the period. The landuse classes show all classes decreased in extent except the cultivated landuse that acrued an increased of 19.9 % between 1984 and 2016. Furthermore, commercial water supply varied significantly between 2010 and 2016 while irrigation scheme is grossly under-utilized from the inception in 1983 to 2016. Finally, the result of socio-economic impacts revealed that majority of the selected communities' members are actually not benefiting from the dam and their livelihoods are not from the dam.

Description: River systems provide a diverse range of ecosystem services, examples include: flood regulation (regulating), fish (provisioning), nutrient cycling (supporting) and recreation (cultural). Developing water resources through the construction of dams (hydropower or irrigation) can enhance the delivery of provisioning ecosystem services. However, these hydrologic alterations result in reductions in less tangible regulating, cultural and supporting ecosystem services. This study seeks to understand how multiple impoundments, abstractions and transfers within the upper Beas River Basin, Western Himalayas, India, are affecting the delivery of supporting ecosystem services. Whilst approaches for assessing supporting ecosystem services are under development, the immediate aim of this paper is to set out a framework for their quantification, using the macroinvertebrate index Lotic-Invertebrate Index for Flow Evaluation (LIFE). LIFE is a weighted measure of the flow velocity preferences of the macroinvertebrate community. Flow records from multiple gauging stations within the basin were used to investigate flow variability at seasonal, inter-annual and decadal time scales. The findings show that both mean monthly and seasonal cumulative flows have decreased over time in the Beas River Basin. A positive hydroecological relationship between LIFE and flow was also identified, indicative of macroinvertebrate response to seasonal changes in the flow regime. For example, high LIFE scores (7.7–9.3) in the winter and summer seasons indicate an abundance of macroinvertebrates with a preference for high flows; this represents a high potential for instream supporting ecosystem services delivery. However, further analysis is required to understand these hydroecological interactions in the study basin and the impact on instream supporting ecosystem services delivery.

Description: Surface water, as the largest part of water resources, plays an important role on China's agricultural production and food security. And surface water is vulnerable to climate change. This paper aims to examine the status of the supply reliability of surface water irrigation, and discusses how it is affected by climate change in rural China. The field data we used in this study was collected from a nine-province field survey during 2012 and 2013. Climate data are offered by China's National Meteorological Information Center which contains temperature and precipitation in the past 30 years. A Tobit model (or censored regression model) was used to estimate the influence of climate change on supply reliability of surface water irrigation. Descriptive results showed that, surface water supply reliability was 74 % in the past 3 years. Econometric results revealed that climate variables significantly influenced the supply reliability of surface water irrigation. Specifically, temperature is negatively related with the supply reliability of surface water irrigation; but precipitation positively influences the supply reliability of surface water irrigation. Besides, climate influence differs by seasons. In a word, this paper improves our understanding of the impact of climate change on agriculture irrigation and water supply reliability in the micro scale, and provides a scientific basis for relevant policy making.

Description: The Aral Sea desiccation and related changes in hydroclimatic conditions on a regional level is a hot topic for past decades. The key problem of scientific research projects devoted to an investigation of modern Aral Sea basin hydrological regime is its discontinuous nature – the only limited amount of papers takes into account the complex runoff formation system entirely. Addressing this challenge we have developed a continuous prediction system for assessing freshwater inflow into the Small Aral Sea based on coupling stack of hydrological and data-driven models. Results show a good prediction skill and approve the possibility to develop a valuable water assessment tool which utilizes the power of classical physically based and modern machine learning models both for territories with complex water management system and strong water-related data scarcity. The source code and data of the proposed system is available on a Github page (https://github.com/SMASHIproject/IWRM2018).

Description: Among the various parameters monitored in river monitoring networks, bioindicators provide very informative data. Analysing time variations in bioindicator data is tricky for water managers because the data sets are often short, irregular, and non-normally distributed. It is then a challenging methodological issue for scientists, as it is in Saône basin (30 000 km2, France) where, between 1998 and 2010, among 812 IBGN (French macroinvertebrate bioindicator) monitoring stations, only 71 time series have got more than 10 data values and were studied here. Combining various analytical tools (three parametric and non-parametric statistical tests plus a graphical analysis), 45 IBGN time series were classified as stationary and 26 as non-stationary (only one of which showing a degradation). Series from sampling stations located within the same hydroecoregion showed similar trends, while river size classes seemed to be non-significant to explain temporal trends. So, from a methodological point of view, combining statistical tests and graphical analysis is a relevant option when striving to improve trend detection. Moreover, it was possible to propose a way to summarise series in order to analyse links between ecological river quality indicators and land use stressors.

Description: As the impacts by climate changes and human activities are intensified, variability may occur in river's annual runoff as well as flood and low water characteristics. In order to understand the characteristics of variability in hydrological series, diagnosis and identification must be conducted specific to the variability of hydrological series, i.e., whether there was variability and where the variability began to occur. In this paper, the mainstream of Yangtze River was taken as the object of study. A model was established to simulate the impounding and operation of upstream cascade reservoirs so as to obtain the runoff of downstream hydrological control stations after the regulation by upstream reservoirs in different level years. The Range of Variability Approach was utilized to analyze the impact of the operation of upstream reservoirs on the variability of downstream. The results indicated that the overall hydrologic alterations of Yichang hydrological station in 2010 level year, 2015 level year and the forward level year were 68.4, 72.5 and 74.3 % respectively, belonging to high alteration in all three level years. The runoff series of mainstream hydrological stations presented variability in different degrees, where the runoff series of the four hydrological stations including Xiangjiaba, Gaochang and Wulong belonged to high alteration in the three level years; and the runoff series of Beibei hydrological station in 2010 level year belonged to medium alteration, and high alteration in 2015 level year and the forward level year. The study on the impact of the operation of cascade reservoirs in Upper Yangtze River on hydrological variability of the mainstream had important practical significance on the sustainable utilization of water resources, disaster prevention and mitigation, safe and efficient operation and management of water conservancy projects and stable development of the economic society.

Description: Many countries, like South Africa, Australia, India, China and the United States, are highly dependent on coal fired power stations for energy generation. These power stations require significant amounts of water, particularly when fitted with technology to reduce pollution and climate change impacts. As water resources come under stress it is important that spatial variability in water availability is taken into consideration for future energy planning particularly with regards to motivating for a switch from coal fired power stations to renewable technologies. This is particularly true in developing countries where there is a need for increased power production and associated increasing water demands for energy. Typically future energy supply options are modelled using a least cost optimization model such as TIMES that considers water supply as an input cost, but is generally constant for all technologies. Different energy technologies are located in different regions of the country with different levels of water availability and associated infrastructure development and supply costs. In this study we develop marginal cost curves for future water supply options in different regions of a country where different energy technologies are planned for development. These water supply cost curves are then used in an expanded version of the South Africa TIMES model called SATIM-W that explicitly models the water-energy nexus by taking into account the regional nature of water supply availability associated with different energy supply technologies. The results show a significant difference in the optimal future energy mix and in particular an increase in renewables and a demand for dry-cooling technologies that would not have been the case if the regional variability of water availability had not been taken into account. Choices in energy policy, such as the introduction of a carbon tax, will also significantly impact on future water resources, placing additional water demands in some regions and making water available for other users in other regions with a declining future energy demand. This study presents a methodology for modelling the water-energy nexus that could be used to inform the sustainable development planning process in the water and energy sectors for both developed and developing countries.

Description: The Gash Delta Spate Irrigation System (GDSIS), located in eastern Sudan with a net command area of 100 000 ha (an area currently equipped with irrigation structures), was established in 1924. The land is irrigated every 3 years (3-year rotation) or every 2 years (2-year rotation) so that about 33 000 or 50 000 ha respectively can be cultivated annually. This study deals with assessing the performance of the 3- and 2-year rotation systems using the Monte Carlo simulation. Reliability, which is a measure of how frequently the irrigation water supply satisfies the demand, and vulnerability, which is a measure of the magnitude of failure, were selected as the performance criteria. Combinations of five levels of intake ratio and five levels of irrigation efficiency for the irrigation water supply of each rotation system were analysed. Historical annual flow data of the Gash River for 107 years were fit to several frequency distributions. The Weibull distribution was the best on the basis of the Akaike information criteria and was used for simulating the ensembles of annual river flow. The reliabilities and vulnerabilities of both rotation systems were evaluated at typical values of intake ratio and irrigation efficiency. The results show that (i) the 3-year rotation is more reliable in water supply than the 2-year rotation, (ii) the vulnerability of the 3-year rotation is lower than that of the 2-year rotation and (iii) therefore the 3-year rotation is preferable in the GDSIS. The sensitivities of reliability and vulnerability to changes in intake ratio and irrigation efficiency were also examined.

Description: A statistical model has been developed for forecasting domestic water demand in Haihe river basin of China due to population growth, technological advances and climate change. Historical records of domestic water use, climate, population and urbanization are used for the development of model. An ensemble of seven general circulation models (GCMs) namely, BCC-CSM1-1, BNU-ESM, CNRM-CM5, GISS-E2-R, MIROC-ESM, PI-ESM-LR, MRI-CGCM3 were used for the projection of climate and the changes in water demand in the Haihe River basin under Representative Concentration Pathways (RCPs) 4.5. The results showed that domestic water demand in different sub-basins of the Haihe river basin will gradually increase due to continuous increase of population and rise in temperature. It is projected to increase maximum 136.22 × 108 m3 by GCM BNU-ESM and the minimum 107.25 × 108 m3 by CNRM-CM5 in 2030. In spite of uncertainty in projection, it can be remarked that climate change and population growth would cause increase in water demand and consequently, reduce the gap between water supply and demand, which eventually aggravate the condition of existing water stress in the basin. Water demand management should be emphasized for adaptation to ever increasing water demand and mitigation of the impacts of environmental changes.

Description: The study examines the interplay among water resources, hydropower generation and agricultural landuse at the Shiroro hydropower station and its environs, in north-central Nigeria. Non-parametric trend analysis, hydropower footprint estimation, reservoir performance analysis, change detection analysis, and inferential statistics were combined to study the water-energy and food security nexus. Results of Mann–Kendall test and Sen's slope estimator for the period 1960 to 2013 showed a declining rainfall trend at Jos, around River Kaduna headwaters at −2.6 mm yr−1, while rainfall at Kaduna and Minna upstream and downstream of the reservoir respectively showed no trend. Estimates of hydropower footprint varied between 130.4 and 704.1 m3 GJ−1 between 1995 and 2013. Power generation reliability and resilience of the reservoir was 31.6 and 38.5 % respectively with year 2011 being the most vulnerable and least satisfactory. In addition to poor reliability and resilience indices, other challenges militating against good performance of hydropower generation includes population growth and climate change issues as exemplified in the downward trend observed at the headwaters. Water inflow and power generation shows a weak positive relationship with correlation coefficient (r) of 0.48, indicating less than optimal power generation. Total area of land cultivated increased from 884.59 km2 in 1986 prior to the commissioning of the hydropower station to 1730.83 km2 in 2016 which signifies an increased contribution of the dam to ensuring food security. The reality of reducing upstream rainfall amount coupled with high water footprint of electricity from the reservoir, therefore requires that a long term roadmap to improve operational coordination and management have to be put in place.

Description: The aim of this study consists in testing the effectiveness of satellite data in order to monitoring shoreline and sedimentary features changes, especially the rapidly changing of Gulf of Tunis coast. The study area is located in the Gulf of Tunis western bay (Southern Mediterranean Sea) which is characterized by sandy beaches of Ghar Melah and Raoued (Medjerda Delta area). The aerial photographs and satellite imageries were used for mapping the evolution of shoreline. Diachronic data (satellite imagery, aerial photography and topographic maps) were used to monitor and to quantify, the evolution of the coastal areas. These thematic data were digitally overlaid and vectorised for highlighting the shoreline changes between 1936 and 2016, in order to map the rate of erosion and accretion along the shoreline. Results show that the accretion and degradation are related to the Medjerda: change of outlet in 1973 and impoundment of the Sidi Salem dam in 1982. We found that the general trend of the coastal geomorphic processes can be monitored with satellite imageries (such as Sentinel A2, Spots 4 and 5), due to its repetitive coverage along the time and their high quality concerning the spectral contrast between land and sea areas. Improved satellite imageries with high resolution should be a valuable tool for complementing traditional methods for mapping and assessing the sedimentary structures (such as shoreline, delta, marine bars), and monitoring especially the lowlands coastal areas (slightly eroded).

Description: The Orinoco River has the third largest discharge in the world, with an annual mean flow of 37 600 m3 s−1 at its outlet to the Atlantic Ocean. Due to the presence of the Guiana Shield on the right bank, the lower reach of the Orinoco has a plan form characterized by contraction and expansion zones. Typical 1–1.5 km wide narrow reaches are followed by 7–8 km wide reaches. A complex pattern of bed aggradation and degradation processes takes place during the annual hydrological regime. A series of Acoustic Doppler Current Profiler (ADCP) transects were collected on an expansion channel in the Orinoco River, specifically over a fluvial island, representative of the lower Orinoco. In this study, temporal series of bathymetric cartography obtained by ADCP profiles combined with Differential Global Position System (DGPS) measurements (with dual-frequency), were used to recover the local displacement of bed forms in this island. The principal aims of this analysis were: (1) to understand the dynamics and evolution of sand waves and bars at this section and (2) to quantify the volume (erosion vs. accretion) of a mid-channel bar with dunes by applying DEM of Difference (DoD) maps on time series of bathymetric data. This required sampling with ADCP transects during the months of: May 2016; November 2016 and April 2017. Each bathymetric transect was measured twice, 1 day apart and on the same trajectory obtained by a GPS receptor. The spatial analysis of these ADCP transects is presented as a novel tool in the acquisition of time series of bathymetry for a relatively deep section (∼20 m) and under variable flow conditions.

Description: Mexico is considered a regional economic and political powerhouse because of the size of its economy, and a large population in constant growth. However, this same growth accompanied by management and governance failures are causing several water crises across the country. The paper aims at identifying and analyzing the drivers of water crises. Water authorities seem to focus solely on large infrastructural schemes to counter the looming water crises, but fail to structure a set of policies for the improvement of management and governance institutions. The paper concludes with the implications of a business-as-usual policy based on infrastructure for solving water problems, which include a non-compliance to the human right to water and sanitation, ecosystem collapses and water conflicts.

Description: Tropical moist ecosystems, such as Ahémé lake, south-west Benin, are increasingly marked by water degradation, linked with the activities of increasing riparian populations. The objective of this study is to analyze sedimentary dynamics and its influence on the changing ecosystem of Ahémé lake from 1961–2010. Data used to carry out the study are records of precipitation, flows, turbidity, suspended sediment, mineral elements and bathymetry. Grain size data from the sieving of sediment samples were used to interpret suspended solids distribution in the lake. Linear correlation coefficients were used to assess the degree of dependence between rainfall and runoff inputs to the lake. Lake depth measurements in some areas of the lake serve to determine the rate of infilling. The sorting index was used to highlight the distribution and origin of sediments in the lake. The results show a degradation of the lake Ahémé ecosystem characterized by infilling of its bed, a high correlation (r=0.90) between rainfall and runoff, seasonal change in physicochemical parameters (total suspended sediment decrease by −91 %) and decrease in fish production by 135.8 t yr−1. The highest mean suspended sediment concentrations in lake inputs occur during high water periods (123 mg L−1) compared to low water periods (11.2 mg L−1).

Description: In this paper, changes of sediment yield and sediment transport were assessed using the Revised Universal Soil Loss Equation (RUSLE) and Geographical Information Systems (GIS). This model was based on the integrated use of precipitation data, Landsat images in 2000, 2005 and 2010, terrain parameters (slope gradient and slope length) and soil composition in Zhifanggou watershed, Gansu Province, Northwestern China. The obtained results were basically consistent with the measured values. The results showed that the mean modulus of soil erosion is 1224, 1118 and 875 t km−2 yr−1 and annual soil loss is 23 130, 21 130 and 16 536 in 2000, 2005 and 2010 respectively. The measured mean erosion modulus were 1581 and 1377 t km−2 yr−1, and the measured annual soil loss were 29 872 and 26 022 t in 2000 and 2005. From 2000 to 2010, the amount of soil erosion was reduced yearly. Very low erosion and low erosion dominated the soil loss status in the three periods, and moderate erosion followed. The zones classified as very low erosion were increasing, whereas the zones with low or moderate erosion were decreasing. In 2010, no zones were classified as high or very high soil erosion.

Description: Apple orchards have previously been bearing 60–80 t ha−1 at most. However in recent years yield has increased to more than 100 t ha−1. There is need to understand the water requirements of the high yielding orchards, given that high crop loads are associated with high water use rates. The aim of this study was to quantify the water requirements of young and mature unstressed apple orchards. We also assess the impact of climate variables on transpiration rates. Data was collected in 4 orchards in the Western Cape Province. The orchards comprised young non-bearing (