雨强和坡度对黄土陡坡地浅沟形态特征影响的定量研究

发布时间：2018-03-09 11:03

本文选题：土壤　切入点：侵蚀　出处：《农业工程学报》2017年11期 　论文类型：期刊论文

【摘要】：浅沟形态特征是建立陡坡地坡面浅沟侵蚀预报模型的基础。为了定量研究黄土陡坡地浅沟形态特征,在长8 m、宽2 m、深0.6 cm的试验土槽上制作了雏形浅沟,设计了2个降雨强度(50、100 mm/h)和3个浅沟发生的典型坡度(15°、20°、25°),利用模拟降雨和径流冲刷(10 L/min)相结合的试验方法定量分析了黄土陡坡地的浅沟形态特征。结果表明:降雨强度和坡度的增加均加快了坡面浅沟侵蚀过程并使浅沟沟槽宽度和深度不断增加,25°和100 mm/h降雨强度下的浅沟沟槽平均宽度和深度比15°和50 mm/h降雨强度下的分别增加1.40和0.61倍。根据测针板法得到的3 cm×10 cm精度的地表高程值数据,在Surfer软件中生成不同试验处理下的地面数字高程模型(DEM,digital elevation model)及水流流路图等,发现坡度的增加使两侧坡面细沟汇入浅沟沟槽的坡长增大,而降雨强度的增加则导致浅沟沟槽两侧坡面细沟汇入浅沟沟槽的坡长缩短,同时,沟道密度、地面割裂度和浅沟复杂度均随着降雨强度和坡度的增加而呈现增大的趋势,三者分别变化于0.74~1.48 m/m2、0.13~0.29和1.64~2.84之间,而不同降雨强度和坡度条件下浅沟沟槽宽深比变化于0.65~1.27之间。基于不同试验处理下的DEM,根据相邻格网关系在水平方向上计算方向导数后发现,方向导数格网等值线图可以有效地反映坡面浅沟和细沟的长度、表面积及侵蚀最严重的浅沟沟底位置。
[Abstract]:Morphological characteristics of shallow gully is based on steep slope shallow gully erosion prediction model. To quantitatively study the loess steep slope of ephemeral gully morphology, in 8 m long, 2 m wide and 0.6 cm deep groove soil test is made on the prototype shallow trench, designed 2 rainfall intensity (50100 mm/h) and typical slope 3 A shallow trench occurred (15 degrees, 20 degrees, 25 degrees), using the simulated rainfall and runoff scouring (10 L/min) quantitative test method of combining the morphological characteristics of shallow gully loess steep slope land. The results show that the increase of rainfall intensity and slope were accelerated shallow gully erosion process and shallow gully width and depth increasing, 25 degrees and 100 mm/h rainfall intensity under shallow gully average width and depth of the 1.40 and 0.61 times respectively more than 15 degrees and 50 mm/h rainfall intensity. According to the surface elevation measuring needle plate method 3 cm * 10 cm the accuracy of the data generated in the Surfer software in The digital elevation model under different treatments (DEM, digital elevation model) and the flow diagram, found that the increase of slope on both sides of the rill into the shallow gully slope length increases, and the increase of rainfall intensity in shallow gully sides of rill into the shallow gully slope length is shortened, at the same time, ditch road density, ground lacerative degree and gully complexity increased with rainfall intensity and slope shows the tendency of increase, three were between 0.74~1.48 m/m2,0.13~0.29 and 1.64~2.84 changes, and different rainfall intensity and slope conditions of shallow gully width to depth ratio changes between 0.65~1.27 under different treatments. Based on DEM, according to the relationship between adjacent grid computing directionalderivatives in the horizontal direction after the discovery, the directional derivative contour map grid can effectively reflect the shallow gully and rill length, surface area and the most serious erosion The position of the heavy shallow gully bottom.

【作者单位】：西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;中国科学院水利部水土保持研究所;沈阳农业大学水利学院;
【基金】：国家自然科学基金资助项目(41271299) 水利部黄土高原水土流失过程与控制重点实验室开放课题基金项目(2017001) 黄土高原土壤侵蚀与旱地农业国家重点实验室重要方向创新项目(A314021403-C2)
【分类号】：S157.1

【参考文献】