气候变化领域集成服务门户(CCPortal): Hydroclimatic control on suspended sediment dynamics of a regulated Alpine catchment: A conceptual approach

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DOI	10.5194/hess-22-3421-2018
	Hydroclimatic control on suspended sediment dynamics of a regulated Alpine catchment: A conceptual approach
	Costa A.; Anghileri D.; Molnar P.
发表日期	2018
ISSN	1027-5606
起始页码	3421
结束页码	3434
卷号	22 期号:6
英文摘要	We analyse the control of hydroclimatic factors on suspended sediment concentration (SSC) in Alpine catchments by differentiating among the potential contributions of erosion and suspended sediment transport driven by erosive rainfall, defined as liquid precipitation over snow-free surfaces, ice melt from glacierized areas, and snowmelt on hillslopes. We account for the potential impact of hydropower by intercepting sediment fluxes originated in areas diverted to hydropower reservoirs, and by considering the contribution of hydropower releases to SSC. We obtain the hydroclimatic variables from daily gridded datasets of precipitation and temperature, implementing a degree-day model to simulate spatially distributed snow accumulation and snow-ice melt. We estimate hydropower releases by a conceptual approach with a unique virtual reservoir regulated on the basis of a target-volume function, representing normal reservoir operating conditions throughout a hydrological year. An Iterative Input Selection algorithm is used to identify the variables with the highest predictive power for SSC, their explained variance, and characteristic time lags. On this basis, we develop a hydroclimatic multivariate rating curve (HMRC) which accounts for the contributions of the most relevant hydroclimatic input variables mentioned above. We calibrate the HMRC with a gradient-based nonlinear optimization method and we compare its performance with a traditional discharge-based rating curve. We apply the approach in the upper Rhône Basin, a large Swiss Alpine catchment heavily regulated by hydropower. Our results show that the three hydroclimatic processes - erosive rainfall, ice melt, and snowmelt - are significant predictors of mean daily SSC, while hydropower release does not have a significant explanatory power for SSC. The characteristic time lags of the hydroclimatic variables correspond to the typical flow concentration times of the basin. Despite not including discharge, the HMRC performs better than the traditional rating curve in reproducing SSC seasonality, especially during validation at the daily scale. While erosive rainfall determines the daily variability of SSC and extremes, ice melt generates the highest SSC per unit of runoff and represents the largest contribution to total suspended sediment yield. Finally, we show that the HMRC is capable of simulating climate-driven changes in fine sediment dynamics in Alpine catchments. In fact, HMRC can reproduce the changes in SSC in the past 40 years in the Rhône Basin connected to air temperature rise, even though the simulated changes are more gradual than those observed. The approach presented in this paper, based on the analysis of the hydroclimatic control of suspended sediment concentration, allows the exploration of climate-driven changes in fine sediment dynamics in Alpine catchments. The approach can be applied to any Alpine catchment with a pluvio-glacio-nival hydrological regime and adequate hydroclimatic datasets. © 2018 Author(s).
语种	英语
scopus关键词	Catchments; Climate change; Crystallography; Curve fitting; Hydroelectric power; Ice; Ice control; Iterative methods; Nonlinear programming; Rain; Reservoirs (water); Rhodium compounds; Runoff; Sediment transport; Sedimentation; Snow; Snow melting systems; Fine sediment dynamics; Hydroclimatic factors; Hydroclimatic variables; Hydropower reservoirs; Nonlinear optimization methods; Suspended sediment concentrations; Swiss alpine catchments; Total suspended sediments; Suspended sediments; algorithm; alpine environment; catchment; concentration (composition); conceptual framework; erosion; hydroelectric power; hydrometeorology; optimization; precipitation (climatology); rating curve; sediment transport; sediment yield; snow accumulation; suspended sediment; temperature; Alps; Rhone Basin; Switzerland
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159994
作者单位	Costa, A., Institute of Environmental Engineering, ETH Zurich, Zurich, 8093, Switzerland; Anghileri, D., Institute of Environmental Engineering, ETH Zurich, Zurich, 8093, Switzerland; Molnar, P., Institute of Environmental Engineering, ETH Zurich, Zurich, 8093, Switzerland
推荐引用方式 GB/T 7714	Costa A.,Anghileri D.,Molnar P.. Hydroclimatic control on suspended sediment dynamics of a regulated Alpine catchment: A conceptual approach[J],2018,22(6).
APA	Costa A.,Anghileri D.,&Molnar P..(2018).Hydroclimatic control on suspended sediment dynamics of a regulated Alpine catchment: A conceptual approach.Hydrology and Earth System Sciences,22(6).
MLA	Costa A.,et al."Hydroclimatic control on suspended sediment dynamics of a regulated Alpine catchment: A conceptual approach".Hydrology and Earth System Sciences 22.6(2018).