Runoff Simulation Using SWAT Model in the Middle Reaches of the Dagu River Basin

This article uses Dagu River basin that is located in Qingdao of Shandong Province as the research object, and sets up the hydrological model using SWAT hydrological model and the software of ARCGIS 9.3 which was combined with the basin DEM figure, soil, land use, the observed meteorological data and runoff data. It then established a simulation for regional hydrology on the basis of the runoff data in 1986-2000 and adjusts sensitive parameters by SWAT CUP-2012. The results showed that the determination coefficient (R2) was higher than 0.8 and Nash efficiency coefficient (NS) was higher than 0.7. Therefore, the simulation results can meet the requirements. In addition, it sets up five different land use scenarios and 25 kinds of assumptions of the weather situations to analyze the surface runoff variation of Dagu River basin with two different scenarios, and then sums up the impact of surface runoff influenced by land use change and climate change in Dagu River. The simulation results have an important reference value and practical significance for the sustainable development of this basin in the future and a reasonable allocation of water resources.