坡面土层底部透水性和坡度对径流产沙特征的影响  

Influence of Bottom Soil Layer Permeability and Slope Gradient on Runoff and Sediment Yield Characteristics

作　　者：刘纪根[1,2] 路良伟 童晓霞 陈锦阳[1,2] 郭雨辉 LIU Ji-gen;LU Liang-wei;TONG Xiao-xia;CHEN Jin-yang;GUO Yu-hui(Soil and Water Conservation Department,Changjiang River Scientific Research Institute,Wuhan 430010,China;Research Center on Mountain Torrent&Geologic Disaster Prevention,Ministry of Water Resources,Wuhan 430010,China)

机构地区：[1]长江科学院水土保持研究所,武汉430010 [2]水利部山洪地质灾害防治工程技术研究中心,武汉430010

出　　处：《长江科学院院报》2025年第2期62-68,90,共8页Journal of Changjiang River Scientific Research Institute

基　　金：国家重点研发计划项目(2021YFE0111900);国家自然科学基金项目(42377330)。

摘　　要：坡面径流产沙过程作为山区暴雨洪水过程的重要组成部分,其变化规律及特征对完善山区暴雨洪水过程研究有重要意义。为明确山区坡面土层底部透水性和坡度对径流产沙特征的影响,采用室内人工模拟连续降雨试验方法,设计了坡顶薄坡底厚的试验土槽,选取官山河流域土壤作为试验用土,研究并总结了不同坡度条件下土质坡面的径流变化规律及土壤侵蚀规律。结果表明:①土槽坡度为5°和25°时,地表径流产流率随雨强增大而增大,且均呈现底部不透水侧产流量大于底部透水侧的规律;坡度为15°时,地表径流产流率呈现波动上升趋势,不同底部透水性土槽的地表径流产流量差异不大。②单场降雨条件下壤中流产流率随产流时间增加呈现增加趋势,各坡度之间壤中流产流率变化规律差异较大,但基本呈现出底部不透水土槽的壤中流产流量大于底部透水侧的;坡度为5°时壤中流产流率与地表径流产流率呈负相关关系,坡度为25°时则为正相关关系。③坡面地表流速随降雨强度增大而增大,坡度为5°和15°时不透水侧流速明显大于透水侧,坡度25°时流速差异不大。④不同坡度条件下,坡面侵蚀主要在第2场降雨和第3场降雨产生;坡度为5°和25°时不透水侧坡面侵蚀速率远大于透水侧,15°时呈现交替波动趋势。Understanding the runoff and sediment yield processes on slopes are of crucial significance in enhancing the research on rainstorm and flood dynamics in mountainous areas.To examine the effects of slope soil permeability and gradient on runoff and sediment yield characteristics in mountainous terrain,an indoor artificial simulated continuous rainfall experiment was conducted.The experiment was conducted on a soil trough with shallow upper section and deep lower section using soil samples from the Guanshan River Basin.The study aimed to investigate and summarize the variations in runoff and soil erosion with different slope gradients.Findings reveal that 1)At 5°and 25°slopes,surface runoff rates increased with escalating rainfall intensity,with higher rates observed on slopes featuring impermeable bottom layers compared to those with permeable layers.At a 15°slope,however,runoff increased with notable fluctuations,and differences in runoff rates between impermeable and permeable bottom layers were not statistically significant.2)Interflow rates escalated over time during each rainfall simulation,displaying significant variations across different slope gradients.Generally,interflow rates were higher on slopes with impermeable bottom layers than on those with permeable layers.Notably,the relationship between interflow rate and surface runoff rate was negatively correlated at 5°slopes and positively correlated at 25°slopes.3)Surface runoff velocities increased with rising rainfall intensity.At 5°and 15°slopes,velocities were significantly higher on impermeable bottom layers compared to permeable ones,whereas at 25°,no significant differences were observed.4)Soil erosion was most pronounced during the second and third rainfall simulations across different slope gradients.Erosion rates were higher on impermeable bottom layers compared to permeable ones at 5°and 25°slopes,but showed fluctuations at 15°slopes.

关 键 词：雨强 坡度 基岩渗透性 产流产沙 连续降雨 

分 类 号：S157.1[农业科学—土壤学]