Critical thresholds for stage division of water erosion process in different ridge systems in mollisol region of Northeast China  

作　　者：JIAO Jian QIN Wei LI Kun-heng XU Hai-chao YIN Zhe HOU Shu-yan 

机构地区：[1]State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China [2]Research Center on Soil and Water Conservation of the Ministry of Water Resources,Beijing 100048,China [3]School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China [4]Heilongjiang Province Hydropower Research Institute,Harbin 150070,China

出　　处：《Journal of Mountain Science》2023年第6期1540-1560,共21页山地科学学报（英文）

基　　金：funded by the IWHR Research&Development Support Program(Grant SE0145B032021);the National Key Research and Development Program of China(Grant 2018YFC0507002);。

摘　　要：Extreme rainfall events on a slope under ridge tillage systems cause concentrated stream soil loss.To analyse the critical thresholds for different stages of water erosion process of ridge systems,simulated rainfall-erosion experiments for the contour wide ridge(CWR),contour narrow ridge(CNR),longitudinal wide ridge(LWR),and longitudinal narrow ridge(LNR)were conducted under four rainfall intensities,with slope gradients of 3°and 5°.For the runoff event,the runoff depth order was LNR>LWR>CWR>CNR;the soil loss order was CNR>LNR>CWR>LWR.The product of slope factor(S)and rainfall erosivity(R)or runoff depth(D),can be adopted as critical thresholds for different stages of runoff and soil erosion process.For the longitudinal ridge systems,R values were provided for LWR and LNR and were the beginning of sheet flow,whereas the product of rainfall erosivity and slope factor(RS)values were provided for LWR and LNR as the beginning of the accelerated concentrated flow.For the contour ridge systems,R values were provided for CWR and CNR as critical thresholds for the beginning of overflow.The product of runoff depth and slope factor(DS)values were 9.98 and 7.73 mm for CWR and CNR,respectively,and were critical thresholds for the beginning of ridge failure;the DS values were 18.45 and 12.75 mm for CWR and CNR,respectively,and were critical thresholds for the beginning of the formation of ephemeral gully erosion.The critical thresholds can distinguish different stages of soil erosion process modelling.

关 键 词：RUNOFF Soil loss THRESHOLD Ridge failure Artificial rainfall simulation 

分 类 号：S157[农业科学—土壤学]