降雨条件下风速对迎风坡坡面细沟侵蚀特征的影响  

Effects of Wind Speed on the Characteristics of Rill Erosion on Windward Slope Under Rainfall Conditions

作　　者：张文博 韩玉国[1,2] 邱业 曲芝旭 吴梦雨 ZHANG Wenbo;HAN Yuguo;QIU Ye;QU Zhixu;WU Mengyu(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Beijing Engineering Research Center of Soil and Water Conservation,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]北京市水土保持工程技术研究中心,北京100083

出　　处：《水土保持学报》2024年第3期12-18,28,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(51879005)。

摘　　要：[目的]为明确风力作用下迎风坡坡面细沟侵蚀特征。[方法]采用人工模拟风驱雨试验,研究在不同风速条件(0,3,5,7 m/s)下迎风坡坡面水沙过程变化规律及细沟形态特征。[结果]与无风坡面相比,迎风坡面产流时间和跌坎出现时间分别增加20.59%~47.06%和33.10%~137.78%,坡面平均流速减小12.86%~22.53%;产流率和产沙率随风速的增加而显著减少(p<0.05),不同风速条件下,迎风坡面产流率变化趋势相近,随着降雨进行产流率逐渐增加,一段时间后保持稳定,不同风速下的阶段性无明显差异。产沙率随降雨历时的延长整体呈先迅速增加后缓慢下降并趋于稳定趋势,产沙率发生变化的节点与跌坎出现时间基本一致。细沟宽度、深度及其波动程度随着风速的增加而减小;细沟宽度、深度及其波动程度随着风速增加而减小;细沟宽深比和细沟倾斜度分别为1.40~1.69和13.47°~14.76°,均随着风速的增加而增大;不同风速条件下,细沟体积、细沟割裂度和细沟密度分别为4.39×10^(3)~10.27×10^(3)cm^(3),0.024~0.042,2.03~2.92 m/m^(2),三者均随风速的增加而减小。[结论]细沟体积、细沟密度和割裂度与坡面侵蚀量均呈极显著正相关关系,是表征迎风坡坡面细沟形态的优选指标。[Objective]This study was aimed to elucidate wind-induced rill erosion characteristics on the windward slope.[Methods]Artificial simulated wind-driven rain experiments were conducted.The study investigated changes in water and sediment processes as well as rill morphology under different wind speed conditions(0,3,5,and 7 m/s).[Results]Compared to slopes without wind,the windward slope exhibited a 20.59%~47.06%increase in flow generation time and a 33.10%~137.78%increase in the occurrence of falling ridges.The average slope flow velocity decreased by 12.86%~22.53%.Runoff and sediment production rates notably decreased with increasing wind speed(p<0.05).The runoff production rate on windward slopes followed a similar trend under different wind speeds,gradually increasing with rainfall before stabilizing over time,with no significant differences observed among stages at different wind speeds.Sediment yield rates increased rapidly with prolonged rainfall duration,followed by a gradual decrease and stabilization.Nodes of sediment yield rate changes aligned closely with the occurrence of falling ridges.Rill dimensions(width,depth,fluctuation degree)decreased with rising wind speed.The width-depth ratio and rill inclination ranged from 1.40 to 1.69 and 13.47 to 14.76 degrees,respectively,increasing with higher wind speeds.Under various wind speed conditions,rill volume,splitting degree,and density ranged from 4.39 to 10.27 cm^(3),0.024 to 0.042,and 2.03 to 2.92 m/m^(2),respectively,all decreasing with increasing wind speed.[Conclusion]The volume,density and degree of fragmentation of rills are all significantly positively correlated with the amount of slope erosion,making them the preferred indicators for characterizing the morphology of rills on windward slopes.

关 键 词：细沟侵蚀 风速 迎风坡 细沟形态 

分 类 号：S157.1[农业科学—土壤学]