流量和坡度对植被水流水动力学特性的影响  

Discharge and Slope on Hydraulic Characteristics of Overland Flow Under Vegetated Coverage

作　　者：王柢渊 杨帆[1] 张宽地[1,2] 吕凡[1] 姬祥祥 国库 WANG Diyuan YANG Fan ZHANG Kuandi LYU Fan JI Xiangxiang GUO Ku(Co11ege of Water Resources and Architectural Engineering,Northwest A ＆ F University, Yang1ing 712100,China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,CAS ＆ MWR,Yangling 712100, China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点试验室,陕西杨陵712100

出　　处：《人民黄河》2017年第6期86-89,93,共5页Yellow River

基　　金：国家自然科学基金资助项目(51579214;51209222;41001159);国家"973"计划项目(2015CB040441);国家级大学生科技创新训练计划项目(201410712082);黄土高原土壤侵蚀与旱地农业国家重点实验室开放基金资助项目(K318009902-1413);流域水循环模拟与调控国家重点实验室开放基金资助项目(IWHR-SKL-2014)

摘　　要：为深入揭示植被覆盖下坡面流阻力的内在规律,系统研究了植被覆盖度为32.32%时6个坡度和12个流量组合下坡面流的流动特性。结果表明:坡面流速随流量的增大而增大,该覆盖度下流态指数值接近1;坡面流从层流变化成过渡流,最后发展成紊流状态,但植被覆盖下坡面流的层流状态与明渠定义的不同;阻力系数随流量的增大而增大,流量是影响阻力的主要因素,而坡度对其影响可以忽略;阻力系数随平均水深和壅降差的增大而增大,壅降差不仅能代表水深对阻力系数的影响,而且能反映植被前壅水和后尾水旋涡的形成程度。Containing the cases of 6 different slope gradients and 12 different discharges, the experiments of overland sheet flow were conduc-ted under the condition of 32.32% of vegetation coverage. The results indicate the following inherent laws of flow regime and resistance char-acteristics. First,flow velocity increases with flow discharges,and the larger value of flow index is close to 1,when vegetation coverage is high. Second,the flow regime transfers from laminar flow into transitional flow and then ends up in turbulent flow. However,the laminar flow regime of overland sheet flow with effects of vegetation is different from that of open channel. Third, resistance coefficient increases with flow discharges,and the major factor affecting the resistance is flow discharge but not slope gradient whose effect can be ignored. Finally,resist- ance coefficient increases with mean depth and the difference of the depth of previous and tail water. The depth of previous and tail water notonly can represent the influence of water depth on the drag coefficient, but also can reflect higher depth and the formation of the tail watervortex before and after the vegetation.

关 键 词：坡面流 刚性植被 阻力系数 水动力学特性 

分 类 号：S157.1[农业科学—土壤学]