黄土丘陵沟壑区黄土坡面侵蚀过程及其影响因素  

Erosion process of loess slope and influencing factors in the loess hilly-gully region, China

作　　者：刘冉 余新晓[1] 蔡强国[2,3] 孙莉英 方海燕[2,3] 贾国栋[1] 和继军 LIU Ran;YU Xin-xiao;CAI Qiang-guo;SUN Li-ying;FANG Hai-yan;JIA Guo-dong;HE Ji-jun(School of Soil and Water Conservation,Beijing Forestry University/Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation,Beijing 100083,Chi-na;Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;Cultivation Base of State Key Laboratory of Urban Environmental Processes and Numerical Simulation,Beijing Key Laboratory of Resources Environment and GIS,Capital Normal University,Beijing 100048,China)

机构地区：[1]北京林业大学水土保持学院/水土保持国家林业和草原局重点试验室,北京100083 [2]中国科学院地理科学与资源研究所,陆地水循环及地表过程重点试验室,北京100101 [3]中国科学院大学资源环境学院,北京100049 [4]首都师范大学,城市环境过程和数字模拟国家重点试验室培育基地,北京资源环境与GIS重点试验室,北京100048

出　　处：《应用生态学报》2021年第8期2886-2894,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41771314,41977069)资助。

摘　　要：降雨强度、坡长、坡度是影响坡面产流产沙的重要因素。为定量分析降雨强度、坡长、坡度对黄土丘陵沟壑区安塞黄土坡面侵蚀过程的影响,本研究基于室内人工模拟降雨试验,分析2个坡长(5、10 m)、3个坡度(5°、10°、15°)、2个降雨强度(60、90 mm·h^(-1))下安塞黄土坡面产流产沙规律。结果表明:初始产流时间随坡长增加呈减小趋势,但总体变化不大;初始产流时间随降雨强度增加而减小,与60 mm·h^(-1)相比,90 mm·h^(-1)下缩短5.7~18 min;10°坡度上的径流起始时间最快。随降雨历时延长,产流率先快速增加,最终逐渐稳定在某一产流率值上下波动;产沙率在产流初期短时间内突然升高,达到最大值后减小,再逐渐达到稳定。产流率和产沙率随坡长和降雨强度的增加而增加,但随坡度变化规律不明显。随着降雨强度、坡长和坡度的增加,总产沙量相应增加。在降雨强度90 mm·h^(-1)时,坡长和坡度分别为10 m和15°的坡面产生了细沟,导致总侵蚀量最大(11885.66 g)。降雨强度为60 mm·h^(-1)时,随着坡长增加单位面积侵蚀量减小,在5~10 m坡段存在临界侵蚀坡长。坡长、坡度和降雨强度对坡面径流过程均有促进作用,降雨强度、坡长和两者之间交互作用对产流率和总侵蚀量的贡献率较大,其中,对产流率贡献最大的影响因素是降雨强度,贡献率为49.8%;坡长对总侵蚀的贡献率最大,为37.8%。Rainfall intensity, slope length, and slope gradient are the important factors affecting runoff and sediment yield. In order to quantitatively analyze the effects of rainfall intensity, slope length, and slope gradient on the erosion process of Ansai loess slope in loess hilly and gully region, we analyzed the variation of runoff and sediment yield on Ansai loess with two slope lengths(5, 10 m), three slopes(5°, 10°, 15°) and two rainfall intensities(60, 90 mm·h^(-1)) in an indoor simulated rainfall experiment. The results showed that the initial runoff generation time decreased with the increases of slope length, though the overall change was not significant. The initial runoff generation time decreased with the increases of rainfall intensity. Compared with the intensity of 60 mm·h^(-1), the initial runoff generation time decreased by 5.7-18 min under the intensity of 90 mm·h^(-1). Among them, the runoff initiation time on the slope of 10° was the fastest. With the duration of rainfall, runoff yield rate increased rapidly at first, and then gradually fluctuated around a certain value. The sediment yield rate increased rapidly in a short period of time at the initial stage of runoff generation, and then decreased after reaching the maximum, and being gradua-lly stable. The rates of runoff and sediment yield increased with the increases of slope length and rainfall intensity, but the law of change with slope was not obvious. With the increases of rainfall intensity, slope length and gradient, the total sediment yield increased accordingly. Under the rainfall intensity of 90 mm·h^(-1), the slope surface with the length of 10 m and slope of 15° generated rill, leading to the highest total erosion amount(11885.66 g). Under the rainfall intensity of 60 mm·h^(-1), the erosion amount per unit area decreased with the increases of slope length, and there was a critical erosion slope length in 5-10 m slope section. Slope length, slope and rainfall intensity all played a promoting role in runoff process. Rainfall

关 键 词：黄土坡面 侵蚀过程 影响因素 模拟降雨 贡献率 

分 类 号：S157.1[农业科学—土壤学]