沟道截断对分布式土壤侵蚀学坡长提取的影响

发布时间：2018-03-27 11:38

本文选题：土壤侵蚀　切入点：通用水土流失方程　出处：《水利学报》2017年05期

【摘要】：地形是影响土壤侵蚀的重要因子,分布式土壤侵蚀学坡长是地形因子的重要参数。坡长与侵蚀过程相关,且受地形影响较大,在提取过程中,遇到沟道截断,坡长不再累计。由于沟头位置较难确定,通常沟道提取采用设置一定的汇水面积阈值来实现。然而,沟道对坡长提取结果的影响、不同阈值对坡长提取结果的影响、在无法确定沟头位置情况下如何更加合理地设置截断阈值等问题,亟待研究。本文以黄土高原县南沟和韭园沟流域DEM为数据源,对沟道引起的坡长截断进行对比分析。结果表明,沟道截断对坡长提取的平均值影响小于对坡长最大值的影响;不同区域对坡长的影响小于阈值设置的影响;黄土高原地区的沟道截断阈值可参考平均坡长降低的变化率为4%来设定。
[Abstract]:Terrain is an important factor affecting soil erosion, and distributed soil erosion slope length is an important parameter of topographic factors. The slope length is no longer accumulated. Because the position of channel head is difficult to determine, the channel extraction is usually realized by setting a certain water catchment area threshold. However, the influence of channel on slope length extraction result, and the influence of different threshold value on slope length extraction result, It is urgent to study how to set the truncation threshold more reasonably under the condition that the location of the gully head can not be determined. In this paper, the DEM of Nangou and Jiuyuan Valley in the county of Loess Plateau is taken as the data source. The results show that the average value of channel truncation is less than that of maximum slope length, and the influence of different regions on slope length is less than that of threshold setting. The channel truncation threshold in the Loess Plateau can be set at a rate of 4% when the average slope length is reduced.
【作者单位】：西北农林科技大学;西北大学城市与环境学院;中国科学院水利部水土保持研究所;
【基金】：国家自然科学基金项目(41301283,41371274,41301507) 欧盟地平线2020研究与创新计划(GA:635750) 黄土高原土壤侵蚀与旱地农业国家重点实验室基金(A314021402-1702)
【分类号】：S157

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