The Runoff Simulation Study In The Source Region Of Yellow River Base On The Multiple Spatial And Temporal Resolution Of Precipitation Data

The source region of Yellow River is a typical of the cold and arid region which in the east of Qinghai-Tibet Plateau,recent observations have shown that the characteristics of precipitation in this area have changed with global warming.Therefore,it is of great scientific significance to investigate the hydrological cycle and the runoff response on climate change with varying precipitation.In this paper,we analysis the applicability of TRMM data and its characteristics in the source region of Yellow River and the surrounding area in the spatial and temporal scale by using the coefficient of correlation relative error and the root mean square error.On the basis of data correlation analysis,we improve the spatial resolution of TRMM data from the original 0.25°to 1 km through the establishment of the relationship between the TRMM data and NDVI data,on the basis of the above work,we simulate the runoff in 2010 by using the downscaled TRMM data and 0.5° grid precipitation data to analyze the effect of two different precipitation data on the accuracy of the model.The result of research show that the observed value of TRMM data is higher than the measured value by the meteorological site as a whole,the data in the higher temperature of April to October is more accurate than the other months,and its accuracy will be improved with the increase of time scales.The analysis of downscaled TRMM data show that the best fitting of TRMM data and NDVI data is 0.75°through the establishment of the relationship between them,the coefficient of correlation in downscaled TRMM is less than the original TRMM data.The simulation precision using by the weather station precipitation data is higher than the downscaled TRMM data and 0.5° grid precipitation data in the SRM model.The simulation precision in the snow melting period is high than that in the non-snow melting period,the simulation accuracy is lower in the peak value of snow melting period.The simulation runoff is lower using the critical temperature which is interpolated by using the precipitation and temperature in the surrounding meteorological site,it means that the runoff transformed by the snowmelt is lower than before with the increasing of critical temperature.