水土保持研究2024，Vol.31Issue(3)：79-89,100,12.DOI:10.13869/j.cnki.rswc.2024.03.038
基于SWAT模型的涪江流域土地利用变化的水沙响应研究
Response of Runoff and Sediment Yields to Land Use Change in Fu River Watershed Based on SWAT Model
摘要
Abstract
[Objective]The aims of this study are to quantitatively analyze the response of runoff and sediment yields to land use change in Fu River Watershed,and to provide scientific evidences for the planning and management of water and soil resources and ecological construction in the river basins.[Methods]The SWAT distributed hydrological model was applied.Three natural scenarios and three extreme scenarios were set up to qualify the variation of land use change during 1990 and 2010 and corresponding contribution rates to watershed runoff and sediment discharge.[Results](1)From 1999 to 2010,the upper reaches of the watershed was dominated by woodland and grassland,comprising approximately 46％of the total watershed area.The middle and lower reaches of the watershed were primarily composed of agricultural and urban areas,with cultivated land accounting for approximately 51％of the total area.As a result of rapid urbanization,urban land and bare land expanded significantly at rates of 95.86％and 434.43％,respectively.Under the natural scenarios,the change rate of water yield was less than 5％,and the change rate of sediment yield is less than 15％.(2)SWAT model had strong applicability in Fu River Watershed,the R2 and NSE values for runoff at calibration and verification periods were 0.86,0.85 and 0.80,0.78,respectively,and for sediment discharge were 0.68,0.67 and 0.68,0.43,respectively.Scenario simulation analyses illustrated the effects of specific land use types on runoff decreased in the order:woodland＞grassland＞bare land.Compared with the base period,the woodland cover scenario reduced runoff by 35.66％.Impact of different land use types on sediment yields decreased in the order:bare land＞woodland＞grassland.Compared with the base period,the bare land scenario increased the sediment yield by 56.74％,and the woodland and grassland decreased sediment yield by 43.57％and 30.04％,respectively.(3)The importance ranking results of independent variables based on random forest algorithm showed that the first three land use types affecting runoff were farmland,woodland and grassland,and the random forest weights were 2.057,2.030 and 1.148,respectively,while grassland,farmland and woodland affected sediment yield most significantly and the random forest weights were 1.753,1.208 and 1.003,respectively.[Conclusion]In addition to farmland,the response of runoff to forestland change is the most significant,and the response of erosion and sediment yield to grassland change is the most significant.The conversion of land use type to grassland and woodland significantly reduces water and sediment yields in the basin,while the bare land has a significant impact on sediment yield in the watershed.This research can provide scientific basis for future land use structure optimization and rational planning of water and soil resources in the Fu River Watershed.关键词
土地利用变化/SWAT模型/情景分析/随机森林算法/涪江流域Key words
land use change/SWAT model/scenario analysis/Random Forest/Fu River Watershed分类
地球科学引用本文复制引用
刘雪妍,张会兰,罗泽宇,张嘉琪,安妮..基于SWAT模型的涪江流域土地利用变化的水沙响应研究[J].水土保持研究,2024,31(3):79-89,100,12.基金项目
国家自然科学基金项目(52279056) （52279056）
"十四五"重点研发项目(2022YFF130009505) （2022YFF130009505）
