人工掏挖坡面侵蚀微地貌演化及其水力学特性分析

发布时间：2018-04-11 08:21

本文选题：人工掏挖 + 侵蚀过程　；参考：《水科学进展》2017年05期

【摘要】：人工掏挖是黄土高原地区夏闲地翻耕时广为应用的耕作方式,为探明其坡面侵蚀过程,利用三维激光扫描仪及Arc GIS软件,阐明其在人工模拟间歇降雨下坡面微地貌、侵蚀产沙及水力学参数演变规律。结果表明:(1)坡面侵蚀历经溅蚀—片蚀、断续细沟、连续细沟3个阶段;降雨截止时细沟平面密度、平均沟深、最大沟长和最大沟深分别增至初始的1.42倍、2.24倍、15.5倍和2.43倍。(2)地表糙度随降雨历时推移从1.706呈近似线性趋势减小至1.488;累积降雨量达80 mm之前,径流量、含沙量随地表糙度的减小增加缓慢,但之后随地表糙度减小增加剧烈。(3)降雨过程中流速呈现波动增加趋势,水流由层流快速过渡至紊流,但始终保持为缓流,水流阻力呈波动下降,且形态阻力一直居于主导地位。人工掏挖耕作坡面在雨强1.5 mm/min、降雨量80 mm以内可起到蓄水保土作用,但在连续强降雨下也更易引起细沟侵蚀。
[Abstract]:Manual digging is a widely used tillage method in summer fallow tillage in the Loess Plateau. In order to find out the process of slope erosion, a 3D laser scanner and Arc GIS software are used to elucidate the microtopography of the slope under the artificial simulation of intermittent rainfall.Evolution of erosion sediment yield and hydraulic parameters.The results show that the slope erosion has gone through three stages: splash-plate erosion, intermittent rill, and continuous rill, and the ravine plane density, mean furrow depth, at the end of rainfall, the slope erosion has experienced three stages: splashing erosion, intermittent rill erosion, continuous rill erosion,The maximum furrow length and maximum furrow depth increased to 1.42 times and 2.24 times respectively 15.5 times and 2.43 times 路m ~ (2)) the surface roughness decreased from 1.706 to 1.488 with rainfall duration, and before the cumulative rainfall reached 80 mm, the runoff was decreased.The sediment content increases slowly with the decrease of surface roughness, but then increases sharply with the decrease of surface roughness.The flow resistance fluctuates and decreases, and the morphological resistance is always dominant.The slope of artificial digging tillage can store water and soil within 1.5 mm / min of rain intensity and 80 mm of rainfall, but it is more likely to cause rill erosion under continuous heavy rainfall.
【作者单位】：西北农林科技大学水利与建筑工程学院;西北农林科技大学中国旱区节水农业研究院;重庆万盛经济技术开发区水务局;
【基金】：国家自然科学基金资助项目(41671276)~~
【分类号】：S157.1

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