SEPAL – a simple GIS-based tool to estimate sediment pathways in lowland catchments
SEPAL – a simple GIS-based tool to estimate sediment pathways in lowland catchments
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SEPAL – 一种基于 GIS 的简单工具，用于估计低地流域的沉积物路径
DOI：
10.5194/adgeo-21-25-2009
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发表时间：
2009
影响因子：
--
通讯作者：
N. Fohrer
中科院分区：
文献类型：
--
作者：
Jens Kiesel;B. Schmalz;N. Fohrer
抽象的。尽管低地土壤流失对土地利用和农业生产力的限制不如受侵蚀影响的山区，但由于水质问题和底质淤积，细粒沉积物进入河流和溪流仍令人担忧。排水沟、河岸和农田是低地地区细泥沙的三个主要来源。为了成功实施减少沉积物输入的措施，对各个进入途径有充分的了解至关重要。为了评估可能的进入路径的重要性，建立了基于 GIS 的方法 (SEPAL)，该方法结合了 ABAG、河岸侵蚀公式和回归方法，以包括排水沟的贡献。 SEPAL 已应用于德国北部的一个研究区。结果显示，流入河流的泥沙15%来自农业排水沟，71%来自河岸，14%来自邻近农田。与现场测绘和采样结果的比较表明该方法是合理的。计算出的年总输沙量为616 t yr−1，实测悬浮泥沙量为636 t yr−1。可以得出结论，该方法适用于估算低地流域的泥沙进入路径和年度泥沙负荷，作为建模项目和进一步调查的基础。然而，需要进一步的工作来获得有关不确定性的充分知识，特别是有关迫使沉积物从排水沟输入的过程的知识。
Abstract. Even though soil loss in the lowlands imposes not as much a restriction on land use and agricultural productivity as in erosion affected mountainous areas, the input of fine sediment into the rivers and streams is a concern due to water quality issues and substrate siltation. Drains, river banks and agricultural fields are the three main sources of fine sediment in lowland regions. For a successful implementation of measures to decrease sediment input a well-founded knowledge of the individual entry pathways is essential. To assess the importance of possible entry pathways, a GIS based methodology (SEPAL) has been established combining the ABAG, a river bank erosion formula and a regression approach to include the contributions of drains. SEPAL has been applied on a study catchment in Northern Germany. The results show that 15% of the sediment input into the river comes from agricultural drains, 71% from river banks and 14% from adjacent fields. A comparison of the results with field-mapping and -sampling shows that the approach is plausible. The calculated total annual sediment input is 616 t yr−1, while the measured suspended sediment load is 636 t yr−1. It can be concluded that the methodology is suitable for estimating sediment entry pathways and annual sediment loads in lowland catchments as a base for modelling projects and further investigations. However, further work is necessary for gaining sound knowledge about uncertainties and especially about the processes forcing sediment input from drains.