陕北黄土丘陵沟壑区坡面侵蚀-沉积过程试验研究  

Soil Erosion and Deposition Processes of Loess Slopes in Loess Hilly and Gully Region

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 Xinxiao;Cai Qiangguo;Sun Liying;Fang Haiyan;Jia Guodong;He Jijun(School of Soil Water Conservation in Beijing Forestry University,Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation,Beijing 100083,China;Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Key Laboratory of Water Cycle and Related Land Surface Processes,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Urban Environmental Processes and Numerical Simulation,Resources Environment and GIS Key Lab of Beijing,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：《水土保持通报》2022年第2期31-37,共7页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“黄土丘陵沟壑区坡面侵蚀过程对临界坡长的响应机制”(52179071),“黄土坡面侵蚀泥沙沉积过程与模拟”(41771314),“黄土坡面细沟形态与土壤再分布空间特征的耦合机制研究”(41977069)。

摘　　要：[目的]分析各影响因素作用下黄土坡面的侵蚀—沉积过程,为陕北黄土丘陵沟壑区水土保持措施的合理布设以及水土流失防治规划提供科学依据。[方法]采用室内人工模拟降雨试验方法对不同坡度、坡长和60 mm/h降雨强度条件下的黄土坡面侵蚀—沉积过程特征开展研究。[结果]①净侵蚀过程主要发生时间为在达到侵蚀速率峰值前后,在降雨开始35 min左右内,侵蚀速率在整个降雨过程出现正负值交替变化,侵蚀过程与沉积过程并存。②坡度为5°,10°,15°时,单位面积侵蚀量随坡长的增加而减少,5—10 m坡段中存在明显的沉积过程和临界侵蚀坡长。试验条件下黄土坡面发生沉积的临界坡长在4—5 m以及5—10 m范围内。③在5°,15°坡度下,整个降雨过程中0—5 m坡段的累计单位面积侵蚀量均大于0—10 m坡段坡面,侵蚀过程中一直伴有沉积现象;10°坡面分别在降雨后15 min左右开始伴有沉积现象出现。[结论]坡度和坡长是影响黄土坡面侵蚀—沉积过程的重要因素,坡面径流含沙量和单位面积侵蚀量可以作为表征黄土坡面侵蚀—沉积特征的重要因子。在治理坡面水土流失时应采用拦截中上坡位径流的水土保持措施。[Objective]The erosion-deposition process of loess slopes under the effects of various influencing factors was studied in order to provide a scientific basis for the rational layout of soil and water conservation measures,and for planning to control and prevent soil and water loss in the loess hilly and gully region of Northern Shaanxi Province.[Methods]The characteristics of erosion-deposition processes on a loess slope under different slope gradients,slope lengths,and 60 mm/h rainfall intensity were studied using an indoor artificial rainfall simulation experiment.[Results]①The net erosion process mainly occurred before and after reaching the peak value of erosion rate.The erosion rates alternated between positive and negative values during the entire rainfall period,and the erosion process coexisted with the deposition process.②When the slope was 5°,10°,and 15°,the erosion per unit area decreased with increasing slope length.There was an obvious deposition process and critical erosion slope length in the 5—10 m slope section.Under the test conditions,the critical slope length of loess slope deposition was in the range of 4—5 m and 5—10 m.③Under the gradient of 5°and 15°,during the entire rainfall process,the cumulative erosion per unit area of the 0—5 m slope section was greater than erosion of the 0—10 m slope section,and there was always deposition in the erosion process.On the 10°slope,deposition began to occur about 15 minutes after rainfall.[Conclusion]Slope gradient and slope length are important factors affecting erosion-deposition processes of a loess slope.The sediment concentration of slope runoff and erosion per unit area can be used as important factors to characterize the erosion-deposition characteristics of a loess slope.To control soil and water loss on a slope,soil and water conservation measures that intercept runoff at the middle and upper slope positions should be adopted.

关 键 词：人工模拟降雨 坡面侵蚀 沉积过程 陕北 黄土丘陵沟壑区 

分 类 号：S157.1[农业科学—土壤学]