The Runoff Response To Climate And Land Use Change Scenarios In Shushui River Basin Of Ganjiang River Based On SWAT Model

Sichuan water is located in Ji’an, Jiangxi Province, and it is the first level tributary of Gan River. The western basin is mountainous and eastern region is hilly.the basin is abundant of lush vegetation, surface soil is loose, the height is big, the torrents happen easily for heavy rainfall.Shu River watershed owns abundant rainfall mainly in the summer when the heavy rainfall happens easily.It is the disaster-prone period of flash floods. Since China is found. flood disasters have occurred several times in Suichuan county where the basin flows,which caused serious personal injury and property poor. This article selected Shu River watershed as the study area.Through the establishment of climate change and land use change scenarios mode, This article analysises that climate change and land use change may produce basin hydrological changes,and provide a reference for the prevention of water resources management and flood disasters in the basin.This article will select the current domestic and international research more distributed hydrological model—SWAT, with arcgis support,We build meteorological, DEM, soil and watershed land use database of Shu River basin, then simulate the runoff of Shu River basin. This article will analysis sensitivity of the ten ones in all parameters,in order to determine the extent of the impact of the parameters on the simulation results, and selected six parameters in calibration. This article simulates monthly runoff among 2004-2009 of Linkeng hydrological station in Shu River watershed among,and calibrate parameters though the monthly runoff among 2004-2005, and use the 2006-2009 monthly runoff to verify the simulation results. The simulation results show that the correlation coefficient(R2), the model efficiency coefficient(Ens) were respectively 0.81,0.80 among calibration period.the correlation coefficient(R2), the model efficiency coefficient(Ens) were 0.82,0.81 in verification period. The result of Runoff Simulation is good. The result can generalize the parameters of Shu River watershed and provide good support for data analysis and evaluation of water resources in the region.By changing climate and land use data, setting various climate / land use change, This article studies Shu River watershed runoff response. In the climate scenario, six kinds of changes are as follows: temperature ? 2 ℃, ? 10% in rainfall, temperature + 2 ℃ while-10% in rainfall, temperature-2 ℃ while + 10% in rainfall. Simulation results show that runoff increases with temperature decreasing, with the rainfall increasing. And the impact of changes in rainfall on runoff becomes more apparent. In the land use scenario, this article set up two kinds of change, namely: on the basis of the original land use, forest is replaced by grasslands; on the basis of the original land use, forest is replaced by bare ground. The simulation results show that with reducing woodland, grassland or bare ground increased, annual runoff basin would tended to decrease. reducing Woodlandalso also affect the distribution of the year in runoff. In the wet period during the year, the runoff will be increased; and in the dry season, the runoff will be reduced. Reducing Woodland will exacerbate uneven distribution of years of runoff and is likely to cause more frequent droughts and floods.