Research Of The Impact Of Land Use Change On Runoff In The Jing River Basin Based On VIC-3L Model

As environment,resources and population problems become more and more outstanding,land use chang has become the focus of global change research.The changing of land use changes the water cycle,etc.So there are far-reaching significance to research the effects of land use change on water resources and to understanding the influence of human activities on the water cycle.In this study,the study area is the Jing River Basin.The main contents are as follows:First,the land ues change and the land use of 1985,2000 and 2010 are analysed.The main land use types in the Jinghe River Basin are farmland and grassland.The area of farmland and grassland accounts for more than 85% of the total area of the Jinghe River Basin.Cultivated land and construction land convert intently.Unused land nearly did not change.Second,the trend of precipitation,temperature and runoff,mutation and cycle are analysed by using the method of Mann-Kendall nonparametric slide a rank correlation test,T test,the cumulative departure curve method and wavelet analysis.Since the 60 s of last century,the runoff and rainfall of the Jinghe River Basin showed a trend of decrease,and the average temperature showed a gradual upward trend.The mutation time of runoff of Zhangjiashan hydrological station is in 1997.The mutation time of precipitation is in 1967.The mutation time of temperature is in 1997.Third,the VIC–3L model is structured to simulate the runoff process in Jing River basin.The VIC-3L model has better adaptability in simulation of runoff in the Jinghe River Basin.The average monthly flow simulated by VIC-3L model had a better accuracy with the efficiency coefficient above 0.5.Fourth,use the calibrated VIC-3L model to simulate the runoff process by setting the different situation of land use,to analysis of different land use change on the influence of many runoff.The results show that,after the conversion of cropland to forest and grassland in the study area.the average annual runoff increased slightly.With the increase of cultivated land and forest land in the study area,the average annual runoff depth decreased.