人工模拟降雨条件下紫色土坡面流水动力学参数特征  

Study on Runoff Hydrodynamics of Purple Soil Slope under the Rainfall Simulation Experiment

作　　者：丁文峰[1] 李亚龙[1] 王一峰[1] 程冬兵[1] 张平仓[1] 

机构地区：[1]长江科学院水土保持研究所,武汉430010

出　　处：《水土保持学报》2010年第2期66-69,共4页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(40901135);国家"十一五"科技支撑项目(2008BAD98B02);国家重点基础研究发展计划(973)(2007CB40720301);中央级公益性科研院所基本科研业务费项目(YWF0716/TB01);水利部江湖治理与防洪重点实验室开放基金(R2007-01)

摘　　要：采用人工模拟降雨法,在3.0m长、1.0m宽的可变坡土槽上,通过4个不同坡度(5°,10°,15°,20°)、5个不同雨强(0.6mm/min,1.1mm/min,1.6mm/min,2.12mm/min,2.54mm/min)的组合实验,对降雨条件下紫色土坡面流水动力参数特征进行了研究。结果表明,在实验的坡度和雨强范围内,紫色土坡面流平均雷诺数Re变化于104.9～1571.7之间,在一定雨强和坡度条件下,坡面流雷诺数Re随实验时间延长而逐渐增大,这主要与坡面形态受降雨侵蚀发生改变后坡面流流态由层流向紊流转变有关;坡面流弗罗德数Fr在各种雨强和坡度条件下都小于1,属缓流状态;坡面流阻力系数f与雷诺数Re无明显关系,但其与佛罗德数Fr之间呈显著的指数关系;曼宁糙率系数n与雷诺数Re之间为幂函数关系,但其与佛罗德数Fr无明显关系。Taken the purple soil slope as the research object,which is 3.0 meters long and 1.0 meter width.A series of simulated rainfall experiments under the different rainfall intensities （0.6 mm/min,1.1 mm/min,1.6 mm/min,2.12 mm/min,2.54 mm/min） and different slope gradients （5°,10°,15°,20°）were conducted.The runoff Reynolds number,Darcy-weisbach resistance f coefficient,manning’ n,and the relationships between the Darcy-weisbach f,manning’s n and the runoff Reynolds number,runoff Froude number were studied.The results show that runoff Reynolds number varies between 104.9 and 1 571.7 in the erosion process and it increases with the experiment time extended.The Froude number of runoff flow smaller than 1 under the all experiments and it is belongs to subcritical condition.Roughness coefficients of Darcy-weisbach f is exponentially related to Froude number and has no apparent relationship with the Reynolds number.But,there is exists a power function relationship between the Roughness coefficients of manning’s n and Froude number,and there is apparent relationship between the Roughness coefficients of manning’s n and Reynold number.

关 键 词：紫色土 坡面流 水动力学参数 

分 类 号：S157.1[农业科学—土壤学]