摘要
根据Green-Ampt方程和坡面流运动波方程,分别利用牛顿迭代和四点隐式差分方法进行求解,在坡面土槽进行恒降雨强度的3场降雨冲刷试验,对模拟计算结果进行验证。结果表明,坡面流过程的模拟计算结果与实测资料符合良好,入渗误差可控制在12%以内,流量误差在13.1%以内。同时利用三维激光扫描仪对每场降雨冲刷后的坡面形态进行了监测,定量分析坡面切沟侵蚀的发育过程。结果表明,随着降雨历时的推延,坡面产流产沙过程基本呈现先急剧变化后稳定的趋势,3场降雨中切沟内流速、径流量、平均产流率、泥沙量、切沟侵蚀强度在44～60min时间段内达到最大,分别为24.71cm/s,272.61L,6.99L/min,15.76kg,13.01kg/m2,切沟形态在3场降雨中,最大沟深达到0.301m,最长沟长达到5.437m,最长沟平均沟宽达到0.289m,左侧沟头最大前进速度为0.53mm/s,右侧沟头最大前进速度为0.48mm/s。
According to Green-Ampt equation and wave equation of movement,the Newton iteration and fourpoint implicit finite difference method were used to simulate the infiltration and the overland flow respectively.Three rainfall scouring experiments with the constant rainfall intensity were carried out to validate the result of the simulation.The results showed that the simulation results were in good agreement with the measured data,infiltration rate errors could be controlled within 12%,flow error within 13.1%.Also,the 3Dlaser scanner was used to monitor the slope pattern after each rainfall.And quantitative analysis of the gully erosion process were carried out,results showed that the process of the runoff and sediment yield presented a trend of dramatic changes before they were stable with the duration of rainfall.The velocity,runoff yield,runoff rate,sediment loads,gully erosion intensity reached 24.71cm/s,272.61L,6.99L/min,15.76kg,13.01kg/m2 in a period time(44～60min)time respectively.The biggest gully depth was 0.301m,the longest gully reached 5.437mlong,the longest gully width was 0.289mon average,the maximum gully head retreat rate was 0.53mm/s on the left,and 0.48mm/s on the right in three rainfall events.
出处
《水土保持学报》
CSCD
北大核心
2013年第4期98-102,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目"黄土沟壑区切沟侵蚀三维数值模拟研究"(41171224)
