黄土坡面细沟流水动力学特性

发布时间：2019-03-18 10:34

【摘要】：我国是土壤侵蚀最严重的国家之一,黄土高原地区的水土流失造成严重的生态环境恶化问题。为探求黄土细沟流的水动力学特性,从水力学及河流运动力学的角度出发,系统研究6种坡度(2°、4°、6°、8°、10°、12°),5种流量(8、16、24、32和40 L/min)组合水槽冲刷试验条件下细沟水流水动力学特征。结果表明:细沟流平均流速与径流流量呈幂函数关系,坡度对其影响较小,其原因同水流强度与床面形态的相互制约有关;黏性底层厚度与坡度、流量均呈现负相关关系;阻力系数与雷诺数无关,说明水流强度增加的同时,床面形态发育愈显著,即水流耗散能量增加愈显著,其值在0.16~1.45之间变化。研究结果对细沟水流水动力学的探究具有一定的理论价值,进而对黄土坡面水土流失治理及生态修复均具有一定的指导意义。
[Abstract]:Soil erosion in China is one of the most serious soil erosion countries, and soil erosion in the Loess Plateau has caused serious ecological environment deterioration. In order to explore the hydrodynamic characteristics of loess rill flow, six slopes (2 掳, 4 掳, 6 掳, 8 掳, 10 掳, 12 掳) were systematically studied from the point of view of hydraulics and river transport dynamics. Dynamic characteristics of rill water flow under scour test conditions of 5 kinds of flume (8, 16, 24, 32 and 40 L/min). The results show that there is a power function relationship between average velocity and runoff discharge in fine gully flow, but the slope has little effect on it, and the reason is related to the mutual restriction between flow intensity and bed surface shape, and there is a negative correlation between viscous bottom thickness and slope and discharge, and there is a negative correlation between viscous bottom thickness and slope and discharge. The resistance coefficient has nothing to do with Reynolds number, which indicates that the more obvious the bed shape development is, the more remarkable the water dissipation energy is, and its value varies between 0.16 and 1.45. The research results have certain theoretical value to the study of the dynamics of rill water flow, and then have certain guiding significance to soil erosion control and ecological restoration on loess slope.
【作者单位】：西北农林科技大学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;
【基金】：国家自然科学基金“坡面含沙水流波流耦合特性及泥沙输移机理研究”(51579214),“黄土区坡面水沙过程空间异质性及其尺度效应研究”(51209222) 中央高校基本科研业务费专项资金“黄土坡面含沙水流能量耗散规律研究”(Z109021564) 黄土高原土壤侵蚀与旱地农业国家重点实验室主任基金“基金超声测量技术研究坡面流流动特性”(A314021402-1619) 流域水循环模拟与调控国家重点实验室开放基金“坡面细沟流能量转化研究”(IWHRSKL-2014)
【分类号】：S157.1

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