Research On Discharge Simulate Based On SWAT Model Under The Climate Scenarios Of Shandian River

Coping with climate change effectively has been becoming a huge task for human being due to prominent climate change and its potential effects. Based on the case study of Inner Mongolia Shandian River basin, this paper applies traditional hydrological statistical method to analyze variation features (1961-2009) of hydrological and meteorological elements at Lanqi station and Duolun station. It applies SWAT model based on ARCGIS9.3interface to simulate the hydrological process of Shandian River basin, based on building the underlying database.This model adopts monthly runoff data between1962and1975to conduct parameter calibration. As well, it takes the period between1986and2001as the model test period to assess the applicability of the model. The result shows that measured and estimated monthly flow rate are closer overall, Nash-Sutcliffe coefficients, as well as correlation coefficients between recorded and simulated discharge for both calibration period and the validation period are all above0.60while relative errors are less then5%.Partly due to intensive human disturbance in the validation period, relative error of validation period is more than12%, indicating SWAT model performs well for monthly discharge simulation, and could be applied to the catchments in the arid or semi-arid regions. However, the model performs poor for these months in which precipitation is extremely larger than multi-mean while neighboring month rainfalls are much lower than normal. Output daily meteorological element sequence under A2, B2and A1B circumstance, according to regional climate model HadCM3of UK Hadley Climate Prediction and Research Center and take the period between1961and1990as the base period, then simulate runoff variation and response process between2011and2050under A2, B2and A1B circumstances. Result shows that temperature presents a rising trend against to the benchmark period under the three scenarios in the next40years. Rainfall and runoff show decreasing trend under A2and B2scenarios. Rainfall shows increasing and the trend of runoff shows decreasing then increasing under A1B scenario.The results could provide scientific supports for climate change and adaptation study. It is of significance to rational allocation and sustainable utilization of future water resource of Shandianhe River basin.