太湖上游西苕溪流域水沙产出特征及影响因素  

Characteristics and Causes of Runoff and Sediment Production in the Xitiaoxi Watershed in the Upper Reaches of Taihu Basin

作　　者：汪澳 高俊峰[2] 闫人华[2] 严嘉龙 Wang Ao;Gao Junfeng;Yan Renhua;Yan Jialong(School of Geographical Sciences,Nanjing University of Information Science and Technology,Nanjing 211800,China;Nanjing Institute of Geography&Limnology,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]南京信息工程大学地理科学学院,南京211800 [2]中国科学院南京地理与湖泊研究所,南京210008

出　　处：《水土保持研究》2024年第6期86-95,共10页Research of Soil and Water Conservation

基　　金：国家重点研发计划项目(2023YFC3208704);国家自然科学基金(42071052,42371043);中国科学院南京地理与湖泊研究所自主部署科研项目(NIGLAS2022GS10)。

摘　　要：[目的]定量分析流域水沙产出时空分布,探究其主要成因,为太湖西苕溪流域内水土保持、生态综合治理提供科学参考。[方法]选取太湖上游西苕溪流域作为研究区,并应用SWAT模型和相关统计方法,研究了该流域2016—2020年水沙时空变化特征及其驱动力。[结果](1)流域内水沙产出主要集中在雨季(4—9月),年均径流深为588 mm,占全年的63.2%。平均产沙量为0.83 t/hm^(2),占全年的75.1%。(2)流域内产水主要集中在流域上游西南地区和下游东北地区,而中部地区相对较低,与流域降雨量分布基本保持一致(相关系数R=0.96)。(3)流域内产沙主要集中在西北平原区和中部河谷地带,坡度梯度小于15°或大于25°且用地类型为耕地的区域。(4)流域内土壤侵蚀以微度侵蚀为主,与耕地面积呈较好的线性函数关系(y=0.0202 x+0.539,R^(2)=0.748,p<0.001),流域内年均产沙量约为(1.02±0.44)t/hm^(2)。[结论]流域水沙产出具有明显的时空分布特征,径流与降雨分布基本一致,产沙与耕地面积和坡度密切相关,未来水资源管理需综合考量这些关键因素。[Objective]The aims of this study are to quantitatively analyze the spatiotemporal distribution of runoff and sediment production in the watershed,to investigate its main causes,and to provide scientific references for soil and water conservation and ecological management in the Xitiaoxi watershed of Lake Taihu.[Methods]The Xitiaoxi watershed in the upper reaches of Taihu basin was selected as the study area.The SWAT model and related statistical methods were applied to study the spatial and temporal characteristics of runoff-sediment variability and its driving forces in the watershed during 2016—2020.[Results](1)The output of runoff and sediment in the watershed was mainly concentrated in the rainy season(April—September),and the average annual runoff depth was 588 mm,accounting for 63.2% of the year.The average sediment production was 0.83 t/hm^(2),accounting for 75.1%of the year.(2)Runoff production in the watershed was mainly concentrated in the upper southwestern part and the lower northeastern part,while the central part was relatively low,which was basically consistent with the distribution of rainfall in the basin(correlation coefficient R=0.96).(3)Sediment production in the watershed was mainly concentrated in the northwest plain area and the central river valley area,where the slope gradient was less than 15°or more than 25°and the land type was cultivated land.(4)Soil erosion in the watershed was mainly slight erosion,and it had a good linear function relationship with the cultivated land area,that is,y=0.0202 x+0.539(R^(2)=0.748,p<0.001),and the average annual sediment production in the watershed was about(1.02±0.44)t/hm^(2).[Conclusion]The runoff and sediment production in the watershed exhibits significant spatiotemporal distribution patterns.Runoff distribution is generally consistent with rainfall distribution,sediment yield is closely related to the area of cultivated land and slope.Water resource management should comprehensively consider these key factors in the future.

关 键 词：水沙输出特征 成因分析 SWAT模型 西苕溪流域 

分 类 号：P333[天文地球—水文科学]