典型喀斯特流域介质结构的降雨-径流机制研究OA北大核心CSTPCD

[Objective]The aims of this study are to investigate the rainfall-runoff mechanism in the medium structure of karst basin,and to provide theoretical references for the rational utilization of water resources and flood and drought prevention in the Central Guizhou region.[Methods]20 typical watersheds in the central Guizhou were selected as the study sample areas,the spatial and temporal distribution characteristics of rainfall and runoff in the watersheds were analyzed,multi-scale rainfall-runoff simulation by using Support Vector Regression(SVR)was carried out,and the rainfall-runoff mechanism of the watershed media structure was analyzed by using Spearman's method.[Results](1)Rainfall in the Central Guizhou from 1979 to 2021 showed a slowly increasing trend(5.02 mm/a)and runoff showed a slowly decreasing trend(-0.017 billion m3/a),and both of them unevenly distributed in the space in general.(2)SVR trained by radial basis kernel function(RBF)was relatively accurate,and simulation accuracy decreased in the order:fall＞winter＞spring＞year-round＞summer.(3)The single-factor single factor effects decreased in the order:non-karst(0.764)＞low activity strong acidic soil(0.566)＞peak forest geomorphic type(0.459)＞grassland(0.456)＞continuity dolomite karst(-0.435)＞cultivated vegetation(-0.426).(4)Single-factor coupled effects decreased in the order:soil cover structure(0.714)＞geomorphic combination structure(-0.529)＞rock composition structure(-0.446)＞vegetation distribution structure(0.323),and multi-factor coupling influence decreasedin the order:234(-0.702)＞1234(-0.679)＞23(0.607)＞34(-0.604)＞24(-0.547)＞134(-0.544)＞13(0.507).[Conclusion]SVR is suitable for the simulation of rainfall-runoff process in the central Guizhou region,and the structure of watershed media has a large influence on rainfall-runoff.