坡面草被覆盖对侵蚀产沙影响的模拟试验  

Experimental Study on Impacts of Vegetation Patterns on Sediment Yield of Slope

作　　者：霍云霈 朱冰冰 HUO Yunpei;ZHU Bingbing(School of Ecnomics and Management,Shaanxi Xueqian Normal University,Xi′an 710100,China;School of Geography and Tourism,Shaanxi Normal University,Xi′an 710119,China)

机构地区：[1]陕西学前师范学院经济与管理学院,西安710100 [2]陕西师范大学地理科学与旅游学院,西安710119

出　　处：《水土保持研究》2022年第5期14-20,共7页Research of Soil and Water Conservation

基　　金：国家自然科学基金(41601285);陕西省重点研发计划(2021ZDYF05-02)。

摘　　要：为了探究坡面植被及其布设位置对坡面侵蚀动力过程的影响,通过室内放水冲刷试验,分析了不同植被覆盖度(0,30%,50%,70%,90%)和不同坡面覆盖位置(坡上、坡中和坡下)下的坡面产沙及其水动力学参数的变化。结果表明:植被覆盖度、径流动能、径流流速、弗汝德数、阻力系数、糙率系数、剪切力等与坡面侵蚀产沙量密切相关。随覆盖度的增加,径流流速、径流剪切力、单位水流功率和径流动能逐渐降低,曼宁糙率系数和阻力系数逐渐增加,产沙量呈直线下降。当覆盖度从0增长到50%时,植被的减沙效益显著提高,当盖度增加到70%时,植被保持水土的作用不随覆盖度的增加显著提高,不同坡面覆盖位置下坡面侵蚀产沙表现为植被位于坡面中下部的产沙量小于植被位于坡面上部的,可用包含植被覆盖度、单位水流功率和径流动能等参数建立的联合公式模拟预测坡面侵蚀产沙量。研究结果可为阐明植被减沙的临界盖度和合理位置以及黄土高原水土流失治理和黄河流域高质量发展提供参考。Understanding the changes of sediment yield and hydrodynamic parameters of slopes under different vegetation patterns is of great significance for revealing the hydrodynamic mechanism and establishing suitable vegetation parameters for indicating sediment processes.In this study,the variations of sediment yield and hydrodynamic parameters of slopes with different vegetation coverage(0,30%,50%,70%,90%)and positions(upslope,middle slope and downslope)of grasslands were analyzed by scouring test.The results show that,grass coverage,runoff kinetic energy,runoff velocity,Fr number,Darcy-Weisbach resistence coefficient,Manning′s roughness coefficient and shear stress were closely related with sediment yield.With the increase of grass coverage,runoff velocity,shear stress,sediment yield,unit stream power and runoff kinetic energy decreased linearly,while Manning′s roughness coefficient and Darcy-Weisbach consistence coefficient increased significantly.When the coverage reached to the range of 50%~70%,the increase of grass coverage couldn′t stimulate high sediment yield reduction which meant the valid coverage was 50%and the threshold coverage was 70%in this study.With the increase of coverage,the impacts of grass position on the sediment yield show a general rule that the sediment yield on the slope with grass cover in middle and downslope is smaller than that in upslope.A simulation forum including coverage,unit stream power and runoff kinetic energy was established to predict sediment yield.The results can provide important theoretical basis for clarifying the threshold of grass coverage on sediment reduction and suitable position and implementing soil erosion countermeasures on the Loess Plateau,and for prompting high quality development of the Yellow River Basin.

关 键 词：坡面 植被格局 侵蚀产沙 水动力学参数 单位水流功率 

分 类 号：S157.1[农业科学—土壤学]