ALBERT

Description: Groundwater is an important part of the hydrological cycle, accounting for more than 25% of human needs on the global scale. As a result of aquifer overexploitation associated with climate change, even in the most conservative future climate scenarios, mean water-table levels can experience drastic drops. Although there are efforts to include groundwater dynamics in global climate models (GCMs), its influence is still not taken into full account in GCM water budgets, although it is as important as the other water sources considered. To assess the role of percolation in the water balance, we compared the water budget from climate forcing scenarios using 10 GCMs with the water budget from experimental data of a basin in São Paulo state, Brazil. We used the delta factor approach to correct the bias of the model's temperature and precipitation for a control period from 1970 to 1999, and calculated evapotranspiration using the Thornthwaite method. Experimental data for runoff and interception were derived for the basin’s representative crops (sugar cane and pasture) for both water budgets. As the GCMs ignore subsurface flow and the only input considered is precipitation and snow melt, the excess surface water is assumed to be redistributed among the other water budget components. The experimental data shows that there is enough available water for infiltration, indicating that recharge cannot be ignored in the water balance. This leads to the possibility of the models’ overestimating the other components to compensate for the ignored recharge.

Description: In most of the northeast region of Brazil rainfall is relatively low, presenting significant inter-annual fluctuations, especially when compared to rainfall in other areas of Brazil. Moreover, evaporative rates (like the ones found in the northeast semi-arid region) are too high, sometimes reaching over 2800 mm annually. Owing to such a climate character, very large areas in northeast Brazil are subjected to recurrent droughts. This paper presents a methodology for the prediction of seasonal rainfall in semi-arid lands of northeast Brazil. A total of 72 raingauge stations of Paraiba State, and 84 in Ceará State were employed, all of them distributed in three and seven homogeneous areas, respectively. A rainy season with different subdivisions was established for each homogeneous area. The zi proportions – the ratio between the cumulative rainfall of the first rainy season period and the rain that falls during the whole rainy season were made to fit the Beta probabilistic model used for calculating the second and eighth deciles and the probability of rainfall above the average rainfall for the second period of the rainy season. The performance of the prognostic model for individual stations of Paraíba State in the period 1996–2000 was evaluated. In the period 1996 to 2000, with rainfall above average, the error was less than 20 %. The methodology adopted proved very accurate for forecasting droughts in northeast Brazil.

Description: This paper aims to evaluate the characteristics of rainfall events of three experimental basins located in northeast Brazil. The study areas are located, one in Ceará State and two in Paraíba State. Thus, the definition of rainfall events was based on two characteristics: minimum inter-event time and minimum event depth. Then, they were classified according to the shape of the hyetograph: to the left rectangular, triangular, and triangular with peak, and to the right, bimodal and unshaped. Evaluation of the percentages of each type of hyetograph and the main characteristics of rainfall events (peak, duration and intensity) was carried out. The results shows that the two experimental basins located in the semi-arid region have similar characteristics, and shapeless events have significant accumulated rainfall.

Description: The Wei River is the largest tributary of the Yellow River in China and it is suffering from water scarcity and water pollution. In order to quantify the amount of water resources in the study area, a hydrological modelling approach was applied by using SWAT (Soil and Water Assessment Tool), calibrated and validated with SUFI-2 (Sequential Uncertainty Fitting program) based on river discharge in the Wei River basin (WRB). Sensitivity and uncertainty analyses were also performed to improve the model performance. Water resources components of blue water flow, green water flow and green water storage were estimated at the HRU (Hydrological Response Unit) scales. Water resources in HRUs were also aggregated to sub-basins, river catchments, and then city/region scales for further analysis. The results showed that most parts of the WRB experienced a decrease in blue water resources between the 1960s and 2000s, with a minimum value in the 1990s. The decrease is particularly significant in the most southern part of the WRB (Guanzhong Plain), one of the most important grain production basements in China. Variations of green water flow and green water storage were relatively small on the spatial and temporal dimensions. This study provides strategic information for optimal utilization of water resources and planning of cultivating seasons in the Wei River basin.

Description: Finding an effective way to deal with the water crisis and the relationship between water and development is a major issue for all levels of government and different economic sectors across the world. Scientific understanding of water risk is the basis for achieving a scientific relationship between water and development, and water risk assessment is currently an important research focus. To effectively deal with the global water crisis, the World Wide Fund for Nature and German Investment and Development Company Limited proposed the concept of water risk and released an online Water Risk Filter in March 2012, which has been applied to at least 85 countries. To comprehensively and accurately reflect the situation of water risk in China, this study adjusts the water risk assessment indicators in the Water Risk Filter, taking the actual situation in China and the difficulty of obtaining the information about the indicators into account, and proposes an index system for water risk evaluation for China which consists of physical risk, regulatory risk and reputational risk. The improved Water Risk Filter is further used to assess the sources and causes of the water risks in 10 first-class and seven second-class water resource areas (WRAs). The results indicate that the water risk for the whole country is generally medium and low, while those for different regions in the country vary greatly, and those for southern regions are generally lower than those for northern regions. Government regulatory and policy implementation as well as media supervision in northern regions should be strengthened to reduce the water risk. The research results may provide decision support and references for both governments and industrial enterprises in identifying water risks, formulating prevention and control policies, and improving water resources management in China.

Description: Water jurisdictions in Australia are required to prepare and implement water resource plans. In developing these plans the common goal is realising the best possible use of the water resources – maximising outcomes while minimising negative impacts. This requires managing the risks associated with assessing and balancing cultural, industrial, agricultural, social and environmental demands for water within a competitive and resource-limited environment. Recognising this, conformance to international risk management principles (ISO 31000:2009) have been embedded within the Murray-Darling Basin Plan. Yet, to date, there has been little strategic investment by water jurisdictions in bridging the gap between principle and practice. The ISO 31000 principles and the risk management framework that embodies them align well with an adaptive management paradigm within which to conduct water resource planning. They also provide an integrative framework for the development of workflows that link risk analysis with risk evaluation and mitigation (adaptation) scenarios, providing a transparent, repeatable and robust platform. This study, through a demonstration use case and a series of workflows, demonstrates to policy makers how these principles can be used to support the development of the next generation of water sharing plans in 2019. The workflows consider the uncertainty associated with climate and flow inputs, and model parameters on irrigation and hydropower production, meeting environmental flow objectives and recreational use of the water resource. The results provide insights to the risks associated with meeting a range of different objectives.

Description: A stochastic downscaling methodology known as the Advanced Weather Generator, AWE-GEN, has been tested at four stations in Peninsular Malaysia using observations available from 1975 to 2005. The methodology involves a stochastic downscaling procedure based on a Bayesian approach. Climate statistics from a multi-model ensemble of General Circulation Model (GCM) outputs were calculated and factors of change were derived to produce the probability distribution functions (PDF). New parameters were obtained to project future climate time series. A multi-model ensemble was used in this study. The projections of extreme precipitation were based on the RCP 6.0 scenario (2081–2100). The model was able to simulate both hourly and 24-h extreme precipitation, as well as wet spell durations quite well for almost all regions. However, the performance of GCM models varies significantly in all regions showing high variability of monthly precipitation for both observed and future periods. The extreme precipitation for both hourly and 24-h seems to increase in future, while extreme of wet spells remain unchanged, up to the return periods of 10–40 years.

Description: Due to the introduction of man-made sediment barriers along a river, the amount of sediment load entering the downstream river reach is different to that leaving the reach, and erosion processes occur downstream of the barrier itself. Designers are often required to take into account the scouring process and to include adequate protective measures against the local scour. This paper addresses the performance of bio-engineering protective measures against the erosion process. In particular, a green carpet, realized with real flexible vegetation, has been used as the protective measure against erosion processes downstream of a rigid bed. Analyses are based on experimental work carried out in a straight channel constructed at the laboratory of the Dipartimento di Ingegneria Civile, Ambientale, Aereospaziale, dei Materiali, Palermo University (Italy).

Description: Balancing the temporal variability of hydrological conditions in the long- and short-term is often essential for steady socio-economic conditions. However, this equilibrium is very fragile in many cases. Hydrological changes or socio-economic changes may destroy it in a short time. If we extend the bearing capacity of socio-hydrological systems we increase, in many cases, the harmful consequences of failures. Here, two case studies are discussed to illustrate these problems. The limited success at adapting water resources to increasing human requirements without consideration of the natural capacities will be discussed with the example of water use for irrigation in northeastern China. The demand for a new planning approach, which is based on a combination of monitoring, model-based impact assessments and spatial distributed planning, is demonstrated. The problems of water surplus, which becomes evident during floods, are discussed in a second case study. It is shown that flood protection depends strongly on expectations of flood characteristics. The gap between the social requirement for complete flood prevention and the remaining risk of flood damage becomes obvious. An increase of risk-awareness would be more sustainable than promises of flood protection, which are the basis for technical measures to affect floods and (or) to prevent flood damages.

Description: Stakeholder participation is increasingly discussed as essential for sustainable water resource management. Yet detailed understanding of the factors driving its use, the processes by which it is employed, and the outcomes or achievements it can realise remains highly limited, and often contested. This understanding is essential to enable water policy to be shaped for efficient and effective water management. This research proposes and applies a dynamic framework that can explore in which circumstances environmental stress events, such as floods, droughts or pollution, drive changes in water governance towards a more participatory approach, and how this shapes the processes by which participation or stakeholder engagement takes place, and the subsequent water management outcomes that emerge. The framework is able to assess the extent to which environmental events in combination with favourable contextual factors (e.g. institutional support for participatory activities) lead to good participatory processes (e.g. well facilitated and representative) that then lead to good outcomes (e.g. improved ecological conditions). Through applying the framework to case studies from the literature it becomes clear that environmental stress events can stimulate participatory governance changes, when existing institutional conditions promote participatory approaches. The work also suggests that intermediary outcomes, which may be tangible (such as reaching an agreement) or non-tangible (such as developing shared knowledge and understanding among participants, or creating trust), may provide a crucial link between processes and resource management outcomes. If this relationship can be more strongly confirmed, the presence or absence of intermediary outcomes may even be used as a valuable proxy to predict future resource management outcomes.