河龙区间典型流域径流年内分配对水土保持生态建设的响应OA北大核心

[Objective]The aim of this study is to reveal the characteristics of multi-year runoff variation in different geomorphic areas in the Hekouzhen-longmen region,and to investigate responses of intra-annual runoff to soil and water conservation measures in these watersheds.[Methods]Three watersheds in different landform regions(Tuwei River,Sanchuan River,and Yan River)were selected,representing the sandy region,rocky mountain region,and loess cover region,respectively.The Gini coefficient and Lorentz asymmetry coefficient were constructed to quantify the evenness of intra-annual runoff using runoff observations during 1960 to 2019.[Results](1)Runoff of Tuwei River,Sanchuan River,and Yan River decreased significantly during 1960 to 2019,with the decrease rate of-0.05 million m3/a,-0.03 million m3/a,and-0.02 million m3/a,respectively.(2)The Intra-annual runoff in different landform regions were different.The Gini coefficients of Tuwei River,Sanchuan River and Yan River were 0.2,0.35 and 0.6,respectively.The intra-annual runoff in the aeolian sandy area showed the highest eveness,followed by the rocky mountain area,while the loess covered area displayed the most uneven distribution.(3)The Gini coefficient of runoff in the three landform regions showed the decreasing trend,and the concentration rate of intra-annual runoff also decreased during 1960 to 2019.(4)NDVI,terraced fields and silting dam construction had significant negative correlation with Gini coefficient of runoff in the three landform regions.[Conclusion]Soil and water conservation projects in the Hekouzhen-Longmen region played a positive role in regulating the intra-annual runoff.