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ABSTRACTTo assess seasonal patterns of suspended sediment load and its erosion–transport interactions, 17 years of river monitoring data from the Isser River Basin (northwest Algeria) were studied, considering continuous and event-scale approaches. The results show significant differences in sediment yield and transport processes between dry and wet periods. A rate of 8 t ha?1 year?1 was estimated from continuous analysis, with values of 4.3 and 13 t ha?1 year?1 for wet and dry periods, respectively. Estimates of soil delivery ratio pointed to higher values during dry periods and the dominance of hillslope erosion processes. At the event scale, the hysteresis loops confirmed these seasonal patterns in transport dynamics. The calibration of the MUSLE model highlighted the severity of rainfall during the dry period. These results emphasize the importance of seasonality in erosion and transport processes with special relevance in terms of climate change predictions. 相似文献
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Sediment yield and transport process assessment from reservoir monitoring in a semi‐arid mountainous river 
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下载免费PDF全文 Soil loss, fluvial erosion, and sedimentation are major problems in semi‐arid environments due to the high associated costs of decreasing services such as provisioning and regulating water resources. The objective of this research is to analyse sediment yield in a mountainous semi‐arid basin, paying special attention to the sources of sediment, the associated uncertainties, and the transport processes involved. The segregation hypothesis along a reservoir of the sediment coming from hillslopes or fluvial systems is also evaluated. For this purpose, bottom‐set and deltaic deposits of a reservoir (110 hm3 ) in southern Spain have been measured and compared with basin erosion and fluvial transport monitoring over a 12‐year period. The volume of sediment stored at the bottomset of the reservoir shows a relative match with parametric predictions based on the Revised Universal Soil Loss Equation/Modified Universal Soil Loss Equation hillslope models and rating curves, estimated as being between 7 and 13 t·ha?1·year?1. Similarly, the measured volume of deltaic deposit fits the average value of stochastic simulations from different bedload transport equations. These contributions represent 50–65% of the total volume measured regarding suspended sediment inputs, way above that described in previous works. This highlights the importance of considering bedload when estimating the useful life of reservoirs in semi‐arid environments. The major differences in sediment grain size between hillslopes and river systems, and the size fractions measured along the reservoir, support the assertion of segregation hypothesis. Nonetheless, based on the processes observed and the uncertainty related to modelling, that assertion has to be taken with caution. At basin scale, a specific sediment yield of between 19 and 24 t·ha?1·year?1 has been estimated, which includes hillslopes and fluvial contributions. This rate is in the range of sediment yield reported for Mediterranean mountain areas of a torrential character. The pulse‐like nature of the system and the spatial heterogeneity of fluvial and hillslope erosion rates points out the importance of considering mid to long‐term and process‐based approaches and emphasizes the limitations of annual estimations for management purposes. 相似文献
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Reyes-Carmona Cristina Galve Jorge Pedro Moreno-Sánchez Marcos Riquelme Adrián Ruano Patricia Millares Agustín Teixidó Teresa Sarro Roberto Pérez-Peña José Vicente Barra Anna Ezquerro Pablo López-Vinielles Juan Béjar-Pizarro Marta Azañón José Miguel Monserrat Oriol Mateos Rosa María 《Landslides》2021,18(12):3781-3798
Landslides - When an active landslide is first identified in an artificial reservoir, a comprehensive study has to be quickly conducted to analyse the possible hazard that it may represent to such... 相似文献
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