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  • Cohesive sediment
  • Humans
  • Remote sensing
  • MDPI AG  (5)
  • Springer Berlin Heidelberg  (4)
  • 1
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    Monitoring crater-wall collapse at active volcanoes: a study of the 12 January 2013 event at Stromboli (2016)
    Springer Berlin Heidelberg
    Details
    Publication Date: 2021-06-22
    Description: Crater-wall collapses are fairly frequent at active volcanoes and they are normally studied through the analysis of their deposits. In this paper, we present an analysis of the 12 January 2013 crater-wall collapse occurring at Stromboli vol- cano, investigated by means of a monitoring network com- prising visible and infrared webcams and a Ground-Based Interferometric Synthetic Aperture Radar. The network re- vealed the triggering mechanisms of the collapse, which are comparable to the events that heralded the previous effusive eruptions in 1985, 2002, 2007 and 2014. The collapse oc- curred during a period of inflation of the summit cone and was preceded by increasing explosive activity and the enlarge- ment of the crater. Weakness of the crater wall, increasing magmastatic pressure within the upper conduit induced by ascending magma and mechanical erosion caused by vent opening at the base of the crater wall and by lava fingering, are considered responsible for triggering the collapse on 12 January 2013 at Stromboli. We suggest that the combination of these factors might be a general mechanism to generate crater-wall collapse at active volcanoes.
    Description: Published
    Description: 39
    Description: 3V. Dinamiche e scenari eruttivi
    Description: JCR Journal
    Description: restricted
    Keywords: Stromboli volcano ; Remote sensing ; Visible and infrared webcam monitoring ; Ground-based radar interferometry ; Crater-wall collapse ; Volcano instability ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 2
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    Remotely sensing the morphometrics and dynamics of a cold region dune field using historical aerial photography and airborne LIDAR data (2018)
    MDPI AG
    Details
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remote Sensing 10 (2018): 792, doi:10.3390/rs10050792.
    Description: This study uses an airborne Light Detection and Ranging (LiDAR) survey, historical aerial photography and historical climate data to describe the character and dynamics of the Nogahabara Sand Dunes, a sub-Arctic dune field in interior Alaska’s discontinuous permafrost zone. The Nogahabara Sand Dunes consist of a 43-km2 area of active transverse and barchanoid dunes within a 3200-km2 area of vegetated dune and sand sheet deposits. The average dune height in the active portion of the dune field is 5.8 m, with a maximum dune height of 28 m. Dune spacing is variable with average crest-to-crest distances for select transects ranging from 66–132 m. Between 1952 and 2015, dunes migrated at an average rate of 0.52 m a−1. Dune movement was greatest between 1952 and 1978 (0.68 m a−1) and least between 1978 and 2015 (0.43 m a−1). Dunes migrated predominantly to the southeast; however, along the dune field margin, net migration was towards the edge of the dune field regardless of heading. Better constraining the processes controlling dune field dynamics at the Nogahabara dunes would provide information that can be used to model possible reactivation of more northerly dune fields and sand sheets in response to climate change, shifting fire regimes and permafrost thaw.
    Description: Funding for this research was provided by the U.S. Geological Survey Land Change Science and Land Remote Sensing programs, the U.S. Fish andWildlife Service and the University of Alaska Fairbanks.
    Keywords: Remote sensing ; LiDAR ; Sand dunes ; Permafrost ; Migration ; Sub-Arctic
    Repository Name: Woods Hole Open Access Server
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  • 3
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    Model behavior and sensitivity in an application of the Cohesive Bed Component of the Community Sediment Transport Modeling System for the York River estuary, VA, USA (2014)
    MDPI AG
    Details
    Publication Date: 2022-05-25
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Marine Science and Engineering 2 (2014): 413-436, doi:10.3390/jmse2020413.
    Description: The Community Sediment Transport Modeling System (CSTMS) cohesive bed sub-model that accounts for erosion, deposition, consolidation, and swelling was implemented in a three-dimensional domain to represent the York River estuary, Virginia. The objectives of this paper are to (1) describe the application of the three-dimensional hydrodynamic York Cohesive Bed Model, (2) compare calculations to observations, and (3) investigate sensitivities of the cohesive bed sub-model to user-defined parameters. Model results for summer 2007 showed good agreement with tidal-phase averaged estimates of sediment concentration, bed stress, and current velocity derived from Acoustic Doppler Velocimeter (ADV) field measurements. An important step in implementing the cohesive bed model was specification of both the initial and equilibrium critical shear stress profiles, in addition to choosing other parameters like the consolidation and swelling timescales. This model promises to be a useful tool for investigating the fundamental controls on bed erodibility and settling velocity in the York River, a classical muddy estuary, provided that appropriate data exists to inform the choice of model parameters.
    Description: Funding by the National Science Foundation (OCE-1061781 and OCE-0536572) supported Fall, Harris, Friedrichs, and Rinehimer.
    Keywords: Cohesive sediment ; Critical stress ; Sediment transport modeling ; Erodibility ; Settling velocity
    Repository Name: Woods Hole Open Access Server
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  • 4
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    Concerns about quadrupole ICP-MS lead isotopic data and interpretations in the environment and health fields (2018)
    MDPI AG
    Details
    Publication Date: 2022-05-25
    Description: © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in International Journal of Environmental Research and Public Health 15 (2018): 723, doi:10.3390/ijerph15040723.
    Description: There has been a massive increase in recent years of the use of lead (Pb) isotopes in attempts to better understand sources and pathways of Pb in the environment and in man or experimental animals. Unfortunately, there have been many cases where the quality of the isotopic data, especially that obtained by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS), are questionable, resulting in questionable identification of potential sources, which, in turn, impacts study interpretation and conclusions. We present several cases where the isotopic data have compromised interpretation because of the use of only the major isotopes 208Pb/206Pb and 207Pb/206Pb, or their graphing in other combinations. We also present some examples comparing high precision data from thermal ionization (TIMS) or multi-collector plasma mass spectrometry (MC-ICP-MS) to illustrate the deficiency in the Q-ICP-MS data. In addition, we present cases where Pb isotopic ratios measured on Q-ICP-MS are virtually impossible for terrestrial samples. We also evaluate the Pb isotopic data for rat studies, which had concluded that Pb isotopic fractionation occurs between different organs and suggest that this notion of biological fractionation of Pb as an explanation for isotopic differences is not valid. Overall, the brief review of these case studies shows that Q-ICP-MS as commonly practiced is not a suitable technique for precise and accurate Pb isotopic analysis in the environment and health fields
    Keywords: Lead isotopes ; ICP-MS ; TIMS ; MC-ICP-MS ; Environment ; Humans ; Rats ; Fractionation
    Repository Name: Woods Hole Open Access Server
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  • 5
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    Evaluating remotely sensed phenological metrics in a dynamic ecosystem model (2014)
    MDPI AG
    Details
    Publication Date: 2022-05-26
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remote Sensing 6 (2014): 4660-4686, doi:10.3390/rs6064660.
    Description: Vegetation phenology plays an important role in regulating processes of terrestrial ecosystems. Dynamic ecosystem models (DEMs) require representation of phenology to simulate the exchange of matter and energy between the land and atmosphere. Location-specific parameterization with phenological observations can potentially improve the performance of phenological models embedded in DEMs. As ground-based phenological observations are limited, phenology derived from remote sensing can be used as an alternative to parameterize phenological models. It is important to evaluate to what extent remotely sensed phenological metrics are capturing the phenology observed on the ground. We evaluated six methods based on two vegetation indices (VIs) (i.e., Normalized Difference Vegetation Index and Enhanced Vegetation Index) for retrieving the phenology of temperate forest in the Agro-IBIS model. First, we compared the remotely sensed phenological metrics with observations at Harvard Forest and found that most of the methods have large biases regardless of the VI used. Only two methods for the leaf onset and one method for the leaf offset showed a moderate performance. When remotely sensed phenological metrics were used to parameterize phenological models, the bias is maintained, and errors propagate to predictions of gross primary productivity and net ecosystem production. Our results show that Agro-IBIS has different sensitivities to leaf onset and offset in terms of carbon assimilation, suggesting it might be better to examine the respective impact of leaf onset and offset rather than the overall impact of the growing season length.
    Keywords: Phenology ; Remote sensing ; Dynamic ecosystem model ; Agro-IBIS ; MODIS
    Repository Name: Woods Hole Open Access Server
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  • 6
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    Variability of bed drag on cohesive beds under wave action (2016)
    MDPI AG
    Details
    Publication Date: 2022-05-26
    Description: © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Water 8 (2016): 131, doi:10.3390/w8040131.
    Description: Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law), a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10 m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold) with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.
    Description: This research was supported by the Office of Naval Research funding of contracts N00014-07-1-0448, N00014-07-1-0756.
    Keywords: Water waves ; Muddy waters ; Coastal waters ; Currents ; Bed drag ; Drag coefficient ; Bottom shear stress ; Bottom friction ; Mud ; Cohesive sediment
    Repository Name: Woods Hole Open Access Server
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  • 7
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    How robust are landslide susceptibility estimates? (2020)
    Ozturk, Ugur ; Pittore, Massimiliano ; Behling, Robert ; [et al.]
    Springer Berlin Heidelberg
    Details
    Publication Date: 2023-06-16
    Description: Much of contemporary landslide research is concerned with predicting and mapping susceptibility to slope failure. Many studies rely on generalised linear models with environmental predictors that are trained with data collected from within and outside of the margins of mapped landslides. Whether and how the performance of these models depends on sample size, location, or time remains largely untested. We address this question by exploring the sensitivity of a multivariate logistic regression—one of the most widely used susceptibility models—to data sampled from different portions of landslides in two independent inventories (i.e. a historic and a multi-temporal) covering parts of the eastern rim of the Fergana Basin, Kyrgyzstan. We find that considering only areas on lower parts of landslides, and hence most likely their deposits, can improve the model performance by 〉10% over the reference case that uses the entire landslide areas, especially for landslides of intermediate size. Hence, using landslide toe areas may suffice for this particular model and come in useful where landslide scars are vague or hidden in this part of Central Asia. The model performance marginally varied after progressively updating and adding more landslides data through time. We conclude that landslide susceptibility estimates for the study area remain largely insensitive to changes in data over about a decade. Spatial or temporal stratified sampling contributes only minor variations to model performance. Our findings call for more extensive testing of the concept of dynamic susceptibility and its interpretation in data-driven models, especially within the broader framework of landslide risk assessment under environmental and land-use change.
    Description: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Keywords: ddc:551.3 ; Landslide susceptibility ; Logistic regression ; Southern Kyrgyzstan ; Landslide inventory ; Remote sensing
    Language: English
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  • 8
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    The state of agricultural landscapes in the Mediterranean: smallholder agriculture and land abandonment in terraced landscapes of the Ricote Valley, southeast Spain (2021)
    Heider, Katharina ; Rodriguez Lopez, Juan Miguel ; Balbo, Andrea L. ; [et al.]
    Springer Berlin Heidelberg
    Details
    Publication Date: 2023-08-01
    Description: The fast and broad adoption of mechanization and chemical inputs in Mediterranean terraced agriculture, combined with warming climate trends, has led to the progressive degradation of environmental and social conditions. These factors have concurred with the increasing abandonment of smallholder agriculture. We aimed to detect and quantify the progression of cultivated and abandoned terraced fields in the Ricote Valley between 2016 and 2019 while also exploring reasons for land abandonment over the past decades. To quantify cultivated and abandoned agricultural terraces, we conducted (1) a terrace detection based on Lidar and cadaster data, (2) a land use classification based on Sentinel imagery, and (3) an investigation of the reasons for land abandonment based on participant observation and an expert survey. Our results show high rates of abandonment compared to the total available agricultural terraced area in the Ricote Valley. In 2016, 56% of the detected terraced area was classified as not cultivated. In 2019, the percentage decreased to 40%. Small parcels are cultivated to a higher percentage than large or medium-sized parcels. We identified five main reasons underlying land abandonment: (1) low income of farmers; (2) land fragmentation resulting in higher transaction costs; (3) lack of interest in agricultural activities among young generations; (4) lack of modernization; and (5) emotional bonds preventing the sale of abandoned parcels. We stressed the importance of a place-based mixed method approach to gain a comprehensive understanding of the specificities of a given research area.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: Friedrich-Ebert-Stiftung http://dx.doi.org/10.13039/501100005846
    Keywords: ddc:631 ; Cultural landscape ; Multifunctionality of agriculture ; Land fragmentation ; Geographic information system ; Mixed method ; Remote sensing
    Language: English
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  • 9
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    Estimation of soil erosion and sediment yield concentration across the Kolleru Lake catchment using GIS (2021)
    Springer Berlin Heidelberg
    Details
    Publication Date: 2023-12-15
    Description: Flat lakes with a large catchment area are especially affected by sediment inputs. The Kolleru Lake catchment (south-eastern India) with a surface area of approximately 6121 km〈sup〉2〈/sup〉 belongs to such types of lake basins. The study’s main objective was the assessment of both soil erosion and sediment yield concentration rate of the Kolleru catchment. The study was conducted using the revised universal soil loss equation (RUSLE) model due to its simple and good applicability for soil erosion estimation. Data such as rainfall, soil texture, topography, crop cover management, and support practice factor were integrated into the modeling using RUSLE and ArcGIS. Field data were used both to analyze the soil texture and the slope length factor. The results showed that average annual soil loss was estimated with 13.6 t/ha/year, classifying the Kolleru Lake Basin under a very high erosion rate category. About 38% of the catchment area has encountered slight soil loss. Areas covered with moderate, strong, severe, very severe erosion potential zones are 29%, 17%, 9%, and 5.5%, respectively. This study identified that upland areas with less vegetation cover exported high potential erosion rates. Unlike the soil loss, the sediment delivery ratio values for the catchment were not affected by land use, while it showed a strong relationship with the catchment drainage system. Whereas, the average annual sediment yield was determined with 7.61 t/ha/year, had identified with the same pattern of the soil erosion. Catchment topography, vegetation, drainage system, soil properties, and land use cover played a major role in exporting the highest sedimentation. The outcome of these studies can be used among others to identify critical erosion areas on a pixel basis for the planning of erosion management practices.
    Description: Philipps-Universität Marburg http://dx.doi.org/10.13039/100008967
    Keywords: ddc:551.3 ; Soil erosion ; Lake catchment ; RUSLE ; Remote sensing ; GIS ; Field data
    Language: English
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