| Water resources is the basic condition of human survival and development.In order to realize the rational allocation and sustainable development of water resources,the hydrological cycle of hydrological cycle has become the most important in hydrological research.The distributed hydrological model SWAT can accurately reflect the hydrological response characteristics of the basin under the conditions of rainfall space and the underlying surface,and it has been widely used.In this paper,the Xihe basin in Liaoning Province as the study area,analysis the hydrological elements changes in hydrological factors,mutations and cycle in recent years.by using of traditional data analysis method.The SWAT distributed hydrological model was used to simulate the hydrological cycle.Exploring the current situation and evolution of hydrological circulation in watershed.concluded as follow:(1)The annual average temperature of the Xihe basin is 8.42?,which shows a increasing trend and reaches a significant level after 1994;there is a cycle time.The average annual precipitation in the basin is 773mm,and the rainfall is concentrated in the summer,accounting for 49%of the annual precipitation.There are 11 transition points in the near 47a and the cycle time of 32a.The correlation coefficient between annual rainfall and annual runoff is 0.813,which is significantly correlated at 0.01 level.The main land use types is forest land,followed by cultivated land and residential area.In the past 30 years,the area of residential area,public land and grassland has increased,and the area of forest land,farmland and water area has decreased(2)Based on DEM,land use,soil,meteorological and other information,in the ArcGIS10.0,SPAW,SwatWeather,Excel and other software support,build up SWAT model of spatial database and attribute database.According to the DEM data,the catchment area threshold is set to 21.96km,and the area threshold of land use,soil and slope is set.The river basin is divided into 28 sub-watersheds and 2061 hydrological response units to construct the SWAT model of the Xihe basin.(3)Based on the ArcSWAT calibration module and the SUFI-2 algorithm provided by SWATCUP software,reference to the monthly runoff data of the Qiaotou hydrological station to make sensitivity analysis,calibration and verification of the model parameters were carried out.Set the 1969-1970 as preheating period,1971-2000 as the calibration period,2001-2000as the verification period,select the correlation coefficient R~2,Nash coefficient Ens and the relative error coefficient Re three indicators on the SWAT model of the analog and the applicability of the Xihe basin.The model calibration periods R~2,Ens and Re are 0.92,0.92and 0.58,and the validation period R2,Ens and Re are 0.89,0.90 and 0.71,which meet the applicability criteria.The SWAT model is more accurate for the hydrological process simulation in the Xihe Basin.(4)Based on the 1985 land use data and the weather data for 1985-2015,25climate change scenarios were set up and brought into the calibrated SWAT model for climate change and climate change simulation of land use.It is concluded that when the rainfall is consistent,the runoff is negatively correlated with the temperature.The rainfall is increased by 20%,and the runoff is increased by 0.62m~3/s for every 1?drop.When the temperature is consistent,the runoff and rainfall Positive correlation:the temperature increased by 2?,10%reduction in rainfall,runoff decreased 2.38m~3/s.Based on the meteorological data from 1985 to 2015,the land use data of 1985 and 2015 were compared and three land use scenarios were established.It was concluded that when the area of forest land and cultivated land increased,the runoff would decrease,When the area of the grass land increase,the runoff will become larger. |
PDF Full Text Request