Quantitative Comparison of Runoff Retention Capacity for Hillslopes with Three Soil Types Across Regions
[Objective]A cross-regional index system was established based on quantitative values to evaluate the runoff retention capacity for slopes of different soil types managed under different practices in order to provide scientific guidance for the prevention and control of soil erosion.[Methods]Runoff plots with four kinds of management measures were set up on a gray calcium soil slope and a brown red soil slope of the northern slope of Yining City,Xinjiang Wei Autonomous Region,and on a purple soil slope of Dashi River basin,Chishui City,Guizhou Province.Based on observed natural rainfall and runoff data from April to September in 2019 to 2021,runoff coefficient,runoff curve number(CN value),and rainfall-runoff production threshold data were used to quantitatively compare the runoff reduction capacity of 12 runoff plots.[Results]The runoff retention capacity of different soils followed the order of gray calcium soil＜brown red soil＜purple soil,and the CN values were 90.05,89.53 and 77.36,respectively.The rainfall-runoff production thresholds were 3.44,3.50,and 14.96 mm,respectively.The results of different evaluation indexes showed that runoff retention capacity of gray calcium soil and brown red soil management measures followed the order of dry grass cover＞horizontal ditch＞seepage hole＞control.Slope flow reduction ability of the purple soil management measures followed the order of garden land＞grassland＞cultivated land＞control.When the runoff coefficient for the control plot increased by 1％,the runoff depth of gray calcium soil,brown-red soil,and purple soil increased by 1.73,2.61,and 6.79 mm,respectively.When the CN value was increased by 1,the runoff depth of the three soil slopes decreased by 1.00,1.00,and 0.71 mm,respectively.[Conclusion]When evaluating runoff reduction capacity of slopes of different soil types across regions,it is recommended to use CN value and rainfall-runoff production threshold,but not runoff coefficient.
across regionsrunoff regulationsoil management measuresSCS-CN modelrainfall-runoff thresholdrunoff reduction capacity
万方数据
维普
