Flood‐based analysis of high‐magnitude sediment transport using a non‐parametric method
Flood‐based analysis of high‐magnitude sediment transport using a non‐parametric method
复制标题
使用非参数方法对高强度泥沙输送进行洪水分析
DOI：
10.1002/esp.1654
复制
发表时间：
2008
影响因子：
3.3
通讯作者：
R. Batalla
中科院分区：
文献类型：
--
作者：
T. Francke;J. López;D. Vericat;A. Bronstert;R. Batalla
高地侵蚀和由此产生的水库淤积是Isábena流域（445平方公里西班牙中部比利牛斯山脉）的一个严重问题。在三个月期间，监测了集水口（卡佩拉）、两个相邻的小集水口（Villacarli， 41平方公里；Cabecera， 145平方公里）和基本荒地集水区Torrelaribera（8公顷）的水和沉积物通量。本文介绍了监测的结果、一种通过间歇测量计算沉降线的方法和监测地点的产沙量。观测到的悬浮沉积物浓度（SSCs）表明了荒地作为沉积物来源的作用：Villacarli地区的SSCs高达280 g l−1，其中包括大片的荒地地区。在Cabecera流域，有大片林地的SSCs勉强超过30 g l−1。直接位于沉积物源（Torrelaribera）的ssc与Villacarli的ssc相当，表明该子集水区内部存在密切联系。在Capella，观察到高达99 g l−1的ssc。对于所有站点，SSC与流量仅表现出松散的相关性，从而抑制了简单沉积物等级曲线的应用。取而代之的是，辅助变量作为驱动力或过程的代理（降雨能量、累积流量、上升/下降的边缘数据）被包括在分位数回归森林模型中，以解释SSC的变异。最具预测能力的变量在不同的地点之间有所不同，表明不同的过程占主导地位。随后基于洪水的产沙量计算证明，在观测期间，Torrelaribera和Villacarli的比产沙量很高（6277和1971 t km−2），Cabecera和Capella的比产沙量中高（139和410 t km−2）。在所有的集水区，大部分沉积物是在夏末的强风暴期间排出的。后来的洪水事件产生的沉积物逐渐减少。将高地产沙量与出水口产沙量联系起来，表明河道内的泥沙储存有相当大的影响。版权所有©2008 John Wiley & Sons， Ltd
Upland erosion and the resulting reservoir siltation is a serious issue in the Isábena catchment (445 km2 Central Spanish Pyrenees). During a three‐month period, water and sediment fluxes have been monitored at the catchment outlet (Capella), two adjacent subcatchments (Villacarli, 41 km2; Cabecera, 145 km2) and the elementary badland catchment Torrelaribera (8 ha). This paper presents the results of the monitoring, a method for the calculation of a sedigraph from intermittent measurements and the derived sediment yields at the monitored locations. The observed suspended sediment concentrations (SSCs) demonstrate the role of badlands as sediment sources: SSCs of up to 280 g l−1 were encountered for Villacarli, which includes large badland areas. SSCs at the Cabecera catchment, with great areas of woodland, barely exceeded 30 g l−1. SSCs directly at the sediment source (Torrelaribera) were comparable to those at Villacarli, suggesting a close connection within this subcatchment. At Capella, SSCs of up to 99 g l−1 were observed. For all sites, SSC displayed only a loose correlation with discharge, inhibiting the application of a simple sediment rating curve. Instead, ancillary variables acting as driving forces or proxies for the processes (rainfall energy, cumulative discharge, rising/falling limb data) were included in a quantile regression forest model to explain the variability in SSC. The variables with most predictive power vary between the sites, suggesting the predominance of different processes. The subsequent flood‐based calculation of sediment yields attests high specific sediment yields for Torrelaribera and Villacarli (6277 and 1971 t km−2) and medium to high yields for Cabecera and Capella (139 and 410 t km−2) during the observation period. In all catchments, most of the sediment was exported during intense storms of late summer. Later flood events yield successively less sediment. Relating upland sediment production to yield at the outlet suggests considerable effects of sediment storage within the river channel. Copyright © 2008 John Wiley & Sons, Ltd.