The Experts below are selected from a list of 11094 Experts worldwide ranked by ideXlab platform
D E Walling - One of the best experts on this subject based on the ideXlab platform.
-
validating the use of 137cs measurements to derive the slope component of the Sediment Budget of a small rangeland catchment in southern italy
Land Degradation & Development, 2016Co-Authors: Paolo Porto, D E Walling, Carmelo La Spada, Giovanni CallegariAbstract:The Sediment Budget is a key concept and tool for characterizing the mobilization, transfer and storage of fine Sediment within a catchment. Caesium-137 measurements can provide valuable information on gross and net erosion rates associated with sheet and rill erosion that can be used to establish the slope component of a catchment Sediment Budget. However, there is a need to validate the use of 137Cs measurements for this purpose, because their reliability has sometimes been questioned. The study reported focuses on a small (3·04 ha) steepland (mean slope 37%) catchment in Southern Italy. It exploits the availability of information on the medium-term Sediment output from the catchment provided by the construction of a reservoir at its outlet in 1978 and the existence of estimates of soil redistribution rates derived from 137Cs measurements made on 68 replicate soil cores collected from the slopes of a substantial proportion of the catchment in 2001, to validate the use of 137Cs measurements to construct the slope component of the catchment Sediment Budget. An additional 50 replicate soil cores were collected from the catchment slopes for 137Cs analysis, to complement the data already available. Nine cores collected from the area occupied by the reservoir were used to estimate the mean annual Sediment input to the reservoir. In the absence of evidence that the poorly developed channel system in the catchment was either a significant Sediment source or sink, it was possible to directly compare the estimate of net soil loss from the catchment slopes (7·33 Mg ha−1 y−1) with the estimate of Sediment output from the catchment provided by the reservoir deposits (7·52 Mg ha−1 y−1). Taking account of the uncertainties involved, the close agreement of the two values is seen as providing a convincing validation of the use of 137Cs measurements to both estimate soil redistribution rates and as a basis for constructing the slope component of the Sediment Budget of a small catchment. Copyright © 2015 John Wiley & Sons, Ltd.
-
establishing a Sediment Budget for a small agricultural catchment in southern brazil to support the development of effective Sediment management strategies
Journal of Hydrology, 2014Co-Authors: Jean Paolo Gomes Minella, D E Walling, Gustavo Henrique MertenAbstract:Summary The rapid expansion of agriculture in Brazil has increased erosion rates and Sediment yields, causing many negative environmental and economic impacts, both on- and off-site. However, to date, very few catchment-scale Sediment Budget investigations have been carried out in Brazil. Given the need to reduce the negative off-site impacts of increasing agricultural activity, there is an important need for such investigations in order to inform the development of effective Sediment management strategies. Against this background, 137Cs measurements have been combined with measurements of Sediment yield and fingerprinting the source of the fine Sediment output, to establish a provisional Sediment Budget for a small (1.19 km2) agricultural catchment in southern Brazil. The catchment is located in an area of steep highly erodible basaltic terrain, which has been intensively cultivated with tobacco. An ongoing monitoring programme provided information on the Sediment yield from the catchment and existing suspended Sediment source fingerprinting investigations provided information on the main Sediment sources contributing to the Sediment load at the catchment outlet. 137Cs measurements have been used to estimate medium-term erosion and deposition rates along 17 transects across the cultivated slopes and to quantify Sedimentation rates within valley floor Sediment sinks. These data have been used to estimate Sediment redistribution rates within the cultivated areas of the study catchment and Sediment accumulation in the valley floor sinks. The information provided by the three primary data sources has been integrated to establish the Sediment Budget for the catchment over the past 57 years. The individual terms of the Budget necessarily involve much uncertainty, but its closure adds confidence to the final result. The Budget calculations indicate that the study catchment has a Sediment delivery ratio of ∼15%. The implications of the key features of the Budget for developing effective Sediment management strategies are discussed.
-
using 137cs and 210pbex measurements to investigate the Sediment Budget of a small forested catchment in southern italy
Hydrological Processes, 2013Co-Authors: Paolo Porto, D E Walling, Giovanni CallegariAbstract:Concern for the sustainability of the soil resource and for the detrimental impacts of fine Sediment on downstream river systems and aquatic ecosystems has directed attention to the need for information on the suspended Sediment loads of rivers. However, traditional measurement programmes focus primarily on quantifying the Sediment load at a catchment outlet. Such information, although useful, may be of limited value in establishing rates of soil degradation, because much of the Sediment mobilized within a catchment may be deposited before reaching the catchment outlet. Furthermore, it may also be of limited value in the design and implementation of Sediment management and control programmes, because this requires an understanding of the key sources of mobilized Sediment, the transport pathways involved and the importance of storage within the catchment. Information on the Sediment Budget of a catchment must be seen as an increasingly important requirement. However, such information is difficult to obtain using conventional traditional monitoring techniques. Fallout radionuclides, including caesium-137 (137Cs) and unsupported or excess lead-210 (210Pbex), have been shown to offer considerable potential for use as Sediment tracers in Sediment Budget investigations. They are able to provide distributed information on rates of soil and Sediment redistribution within the catchment, which represents a valuable complement to information on Sediment output. This contribution reports the results of a study aimed at exploring the use of both 137Cs and 210Pbex measurements to establish the Sediment Budget for the small (1.39 km2) forested Bonis catchment, located in southern Italy. The results confirm that 137Cs and 210Pbex measurements can provide a valuable tool for quantifying both erosion and Sediment redistribution within a catchment and therefore for establishing its Sediment Budget. Copyright © 2012 John Wiley & Sons, Ltd.
-
the catchment Sediment Budget as a management tool
Environmental Science & Policy, 2008Co-Authors: D E Walling, A L CollinsAbstract:Abstract There is increasing recognition that fine Sediment represents an important diffuse source pollutant in surface waters, due to its role in governing the transfer and fate of many substances, including nutrients, heavy metals, pesticides and other organic contaminants, and because of its impacts on aquatic ecology. Catchment management strategies therefore frequently need to include provision for the control of Sediment mobilisation and delivery. The Sediment Budget concept provides a valuable framework for assisting the management and control of diffuse source Sediment pollution and associated problems, by identifying the key sources and demonstrating the importance of intermediate stores and the likely impact of upstream mitigation strategies on downstream suspended Sediment and Sediment-associated contaminant fluxes. Accordingly, the utility of the Sediment Budget concept for catchment management is further discussed, by introducing examples from several contrasting river basins.
-
using cosmogenic beryllium 7 as a tracer in Sediment Budget investigations
Geografiska Annaler Series A-physical Geography, 2002Co-Authors: William H. Blake, D E WallingAbstract:Recent advances in the use of the environmental radionuclides caesium-137 and unsupported lead-210 to quantify medium- and longer-term rates of erosion and Sediment accumulation have proved of considerable value in catchment Sediment Budget investigations. However, there remains a need to explore the potential for using other shorter-lived radionuclides to provide evidence of Sediment mobilisation, transport and storage over shorter timescales and particularly for individual events. This contribution reports the results of a study aimed at exploring the potential for using beryllium-7 ( 7 Be,t 1/2 = 53.3 days) to meet this requirement. The study investigated the use of 7 Be as a Sediment tracer in three key components of the Sediment Budget, namely, soil erosion and Sediment mobilisation from slopes, the transport, storage and remobilisation of fine Sediment in river channels and overbank deposition on river floodplains. The results presented clearly demonstrate the potential for using 7 Be to obtain information on short-term and event-based Sediment redistribution rates for use in catchment Sediment Budget investigations.
Jiin-fa Lee - One of the best experts on this subject based on the ideXlab platform.
-
The role of the Sediment Budget in understanding debris flow susceptibility.
Earth Surface Processes and Landforms, 2009Co-Authors: Jia-jyun Dong, Chyi-tyi Lee, Yu-hsiang Tung, Chia-nan Liu, Kuang-ping Lin, Jiin-fa LeeAbstract:This study proposes a Sediment-Budget model to predict the temporal variation of debris volume stored in a debris-flow prone watershed. The Sediment-Budget is dominated by shallow landslides and debris outflow. The basin topography and the debris volume stored in the source area of the debris-flow prone watershed help evaluating its debris-flow susceptibility. The susceptibility model is applied to the Tungshih area of central western Taiwan. The importance of the debris volume in predicting debris-flow susceptibility is reflected in the standardized coefficients of the proposed statistical discriminant model. The high prediction rate (0·874) for the occurrence of debris flows justifies the capability of the proposed susceptibility models to predict the occurrence of debris flows. This model is then used to evaluate the temporal evolution of the debris-flow susceptibility index. The analysis results show that the numbers of watershed which are classified as a debris-flow group correspond well to storage of Sediment at different time periods. These numbers are 10 before the occurrence of Chi-Chi earthquake, 13 after the occurrence of Chi-Chi earthquake, 16 after the occurrence of landslides induced by Typhoon Mindulle (Typhoon M), and 14 after the occurrence of debris flows induced by Typhoon M. It indicates that the occurrence of 7·6 Chi-Chi earthquake had significant impact on the debris flow occurrence during subsequent typhoons. Copyright © 2009 John Wiley & Sons, Ltd.
Giovanni Callegari - One of the best experts on this subject based on the ideXlab platform.
-
validating the use of 137cs measurements to derive the slope component of the Sediment Budget of a small rangeland catchment in southern italy
Land Degradation & Development, 2016Co-Authors: Paolo Porto, D E Walling, Carmelo La Spada, Giovanni CallegariAbstract:The Sediment Budget is a key concept and tool for characterizing the mobilization, transfer and storage of fine Sediment within a catchment. Caesium-137 measurements can provide valuable information on gross and net erosion rates associated with sheet and rill erosion that can be used to establish the slope component of a catchment Sediment Budget. However, there is a need to validate the use of 137Cs measurements for this purpose, because their reliability has sometimes been questioned. The study reported focuses on a small (3·04 ha) steepland (mean slope 37%) catchment in Southern Italy. It exploits the availability of information on the medium-term Sediment output from the catchment provided by the construction of a reservoir at its outlet in 1978 and the existence of estimates of soil redistribution rates derived from 137Cs measurements made on 68 replicate soil cores collected from the slopes of a substantial proportion of the catchment in 2001, to validate the use of 137Cs measurements to construct the slope component of the catchment Sediment Budget. An additional 50 replicate soil cores were collected from the catchment slopes for 137Cs analysis, to complement the data already available. Nine cores collected from the area occupied by the reservoir were used to estimate the mean annual Sediment input to the reservoir. In the absence of evidence that the poorly developed channel system in the catchment was either a significant Sediment source or sink, it was possible to directly compare the estimate of net soil loss from the catchment slopes (7·33 Mg ha−1 y−1) with the estimate of Sediment output from the catchment provided by the reservoir deposits (7·52 Mg ha−1 y−1). Taking account of the uncertainties involved, the close agreement of the two values is seen as providing a convincing validation of the use of 137Cs measurements to both estimate soil redistribution rates and as a basis for constructing the slope component of the Sediment Budget of a small catchment. Copyright © 2015 John Wiley & Sons, Ltd.
-
using 137cs and 210pbex measurements to investigate the Sediment Budget of a small forested catchment in southern italy
Hydrological Processes, 2013Co-Authors: Paolo Porto, D E Walling, Giovanni CallegariAbstract:Concern for the sustainability of the soil resource and for the detrimental impacts of fine Sediment on downstream river systems and aquatic ecosystems has directed attention to the need for information on the suspended Sediment loads of rivers. However, traditional measurement programmes focus primarily on quantifying the Sediment load at a catchment outlet. Such information, although useful, may be of limited value in establishing rates of soil degradation, because much of the Sediment mobilized within a catchment may be deposited before reaching the catchment outlet. Furthermore, it may also be of limited value in the design and implementation of Sediment management and control programmes, because this requires an understanding of the key sources of mobilized Sediment, the transport pathways involved and the importance of storage within the catchment. Information on the Sediment Budget of a catchment must be seen as an increasingly important requirement. However, such information is difficult to obtain using conventional traditional monitoring techniques. Fallout radionuclides, including caesium-137 (137Cs) and unsupported or excess lead-210 (210Pbex), have been shown to offer considerable potential for use as Sediment tracers in Sediment Budget investigations. They are able to provide distributed information on rates of soil and Sediment redistribution within the catchment, which represents a valuable complement to information on Sediment output. This contribution reports the results of a study aimed at exploring the use of both 137Cs and 210Pbex measurements to establish the Sediment Budget for the small (1.39 km2) forested Bonis catchment, located in southern Italy. The results confirm that 137Cs and 210Pbex measurements can provide a valuable tool for quantifying both erosion and Sediment redistribution within a catchment and therefore for establishing its Sediment Budget. Copyright © 2012 John Wiley & Sons, Ltd.
Anna Smetanova - One of the best experts on this subject based on the ideXlab platform.
-
landform transformation and long term Sediment Budget for a chernozem dominated lowland agricultural catchment
Catena, 2017Co-Authors: Gert Verstraeten, Anna Smetanova, Bastiaan Notebaert, Markus Dotterweich, Ales LetalAbstract:Abstract The loess hilly lands of the South-West Foreland of the West Carpathians are characterized by favorable climatic conditions, smooth topography, fertile soils and a long settlement history. For the first time, we document changes to human-induced landforms in a small zero-order dry valley (0.28 km2) with Calcic Chernozem soils and develop a long-term Sediment Budget. The original surface was reconstructed based on interpreting records of erosion and deposition from 185 soil cores and six valley cross-sections. The topography inherited from the Pleistocene was transformed through lowering of hillslope ridges and convexities, along with infilling of shallow depressions within the original valley bottom. On convex-convex landforms had an average net erosion of − 0.32 ± 0.01 m, while average net accumulation in the valley bottom was estimated at 0.20 ± 0.01 m. The correlation between change in soil profile depth with profile curvature (− 0.51, p
-
Landform transformation and long-term Sediment Budget for a Chernozem-dominated lowland agricultural catchment
CATENA, 2017Co-Authors: Anna Smetanova, Gert Verstraeten, Bastiaan Notebaert, Markus Dotterweich, Ales LetalAbstract:The loess hilly lands of the South-West Foreland of the West Carpathians are characterized by favorable climatic conditions, smooth topography, fertile soils and a long settlement history. For the first time, we document changes to human-induced landforms in a small zero-order dry valley (0.28 km(2)) with Calcic Chernozem soils and develop a long-term Sediment Budget. The original surface was reconstructed based on interpreting records of erosion and deposition from 185 soil cores and six valley cross-sections. The topography inherited from the Pleistocene was transformed through lowering of hilislope ridges and convexities, along with infilling of shallow depressions within the original valley bottom. On convex-convex landforms had an average net erosion of -0.32 +/- 0.01 m, while average net accumulation in the valley bottom was estimated at 0.20 +/- 0.01 m. The correlation between change in soil profile depth with profile curvature (-0.51, p < 0.01) was stronger than with slope (-0.42, p < 0.01). The Sediment Budget was calculated using the Average Per Unit (APU) approach. When slope classes were used in calculating net soil loss from catchments was 143.10(3) Mg.km(-2), whereas 154.10(3) Mg.km(-2) was estimated when morphometric forms of hillslopes were used instead. Both values are < 60% of estimates for similar loess catchments in Central and Western Europe. Prior to 1949, the landscape structure was characterized by small and narrow fields and vegetative field barriers that limited water and aeolian Sediment fluxes in the direction of the thalweg and main wind directions. The landscape structure favoured the low-intensity tillage, erosion and accumulation within fields, and short distance sheet and rill erosion on hillslopes. The land-use changes in the 1950's caused removal of barriers for water and aeolian Sediment transport, and changed the direction of Sediment fluxes of tillage erosion. Past landscape structures should thus be considered when establishing and interpreting Sediment Budgets for lowland agricultural catchments.
Jia-jyun Dong - One of the best experts on this subject based on the ideXlab platform.
-
The role of the Sediment Budget in understanding debris flow susceptibility.
Earth Surface Processes and Landforms, 2009Co-Authors: Jia-jyun Dong, Chyi-tyi Lee, Yu-hsiang Tung, Chia-nan Liu, Kuang-ping Lin, Jiin-fa LeeAbstract:This study proposes a Sediment-Budget model to predict the temporal variation of debris volume stored in a debris-flow prone watershed. The Sediment-Budget is dominated by shallow landslides and debris outflow. The basin topography and the debris volume stored in the source area of the debris-flow prone watershed help evaluating its debris-flow susceptibility. The susceptibility model is applied to the Tungshih area of central western Taiwan. The importance of the debris volume in predicting debris-flow susceptibility is reflected in the standardized coefficients of the proposed statistical discriminant model. The high prediction rate (0·874) for the occurrence of debris flows justifies the capability of the proposed susceptibility models to predict the occurrence of debris flows. This model is then used to evaluate the temporal evolution of the debris-flow susceptibility index. The analysis results show that the numbers of watershed which are classified as a debris-flow group correspond well to storage of Sediment at different time periods. These numbers are 10 before the occurrence of Chi-Chi earthquake, 13 after the occurrence of Chi-Chi earthquake, 16 after the occurrence of landslides induced by Typhoon Mindulle (Typhoon M), and 14 after the occurrence of debris flows induced by Typhoon M. It indicates that the occurrence of 7·6 Chi-Chi earthquake had significant impact on the debris flow occurrence during subsequent typhoons. Copyright © 2009 John Wiley & Sons, Ltd.