Importance of bank erosion for sediment input, storage and export at the catchment scale
Importance of bank erosion for sediment input, storage and export at the catchment scale
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DOI：
10.1007/s11368-012-0597-7
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发表时间：
2013-01-01
影响因子：
3.6
通讯作者：
Audet, Joachim
中科院分区：
文献类型：
--
作者：
Kronvang, Brian;Andersen, Hans E.;Audet, Joachim
对丹麦欧登塞河 486 km(2) 流域的三个时期（2006 年 10 月至 2007 年 4 月、2007 年 5 月至 2008 年 4 月和 2008 年 5 月至 2009 年 4 月）河岸侵蚀的重要性进行了量化。建立了流域沉积物预算，包括其他沉积物来源，例如瓦排水沟和地表径流、河道内和河岸汇和储存以及由此产生的河床负荷和从流域输出的悬浮沉积物负荷。在 180 个销钉图中建立了 3,000 个侵蚀销钉，每个销钉由三条垂直销钉线组成。通过 GIS 中的分层随机程序选择了 36 个代表性河段，每个长度为 100 m。使用床荷采样器和出水口测量站连续测量浊度来测量流域的床荷和悬浮泥沙输出量。在三个研究期间，欧登塞河流域河岸侵蚀输入的总泥沙量为 21,100-25,200 吨，远高于瓦排水沟和地表径流的泥沙估计输入量（220-500 吨）和 分别为0-100吨。在三个研究期间，测得的底床负荷（20-490吨）比流域悬浮沉积物输出量（1,240-2,620吨）低5至60倍，其中最大差异发生在最干旱的年份。沉积物汇和储存对于流域沉积物预算非常重要，因为测量的河岸沉积物河道内储存量高达 16,200-20,100 吨，河岸沉积物汇估计为 360-3,100 吨。在三个研究年中，河岸侵蚀是欧登塞河流域的主要沉积物来源（90-94%）。河道内和河堤上的沉积物汇和储存在沉积物预算中占主导地位，因为在三个研究年中，来自所有来源的沉积物输入的 79-94% 没有从流域输出。河道和洪泛区沉积物的如此大幅度减少对于河流生境和生态极为重要。此外，它对于记录实施缓解措施后沉积物出口变化的尝试具有重大影响。
The importance of bank erosion was quantified during three periods (October 2006-April 2007, May 2007-April 2008 and May 2008-April 2009) in the 486 km(2) catchment area of River Odense, Denmark. A catchment sediment budget was established including other sediment sources such as tile drains and surface runoff, in-channel and overbank sinks and storage and the resulting bed load and suspended sediment load exported from the catchment.Bank erosion and sedimentation were measured using ca. 3,000 erosion pins established in 180 pin plots, each consisting of three vertical lines of pins. Thirty-six representative reaches, each with a length of 100 m, were selected by a stratified random procedure in GIS. Bed load and suspended sediment export from the catchment were measured using a bed load sampler and from continuous measurements of turbidity at the outlet gauging station.The gross sediment input from bank erosion during the three study periods amounted to 21,100-25,200 t in the River Odense catchment, which is considerably higher than the estimated input of sediment from tile drains and surface runoff, which amounted to 220-500 t and 0-100 t, respectively. The measured bed load (20-490 t) was five to 60 times lower than the suspended sediment export from the catchment (1,240-2,620 t) during the three study periods, with the largest difference occurring in the driest year. Sediment sinks and storage were of high importance for the catchment sediment budget as the measured in-channel storage of sediment on stream banks was as high as 16,200-20,100 t, and the overbank sediment sink was estimated at 360-3,100 t.Bank erosion was the dominant sediment source (90-94 %) in the River Odense catchment during the three study years. In-channel and overbank sediment sinks and storage dominated the sediment budget as 79-94 % of the sediment input from all sources was not exported from the catchment during the three study years. Such a large attenuation of sediment in river channels and on floodplains is extremely important for fluvial habitats and ecology. Moreover, it has strong implications for attempts to document changes in sediment export following implementation of mitigation measures.