Combined Remote Sensing And Distributed Hydrological Model To Estimate The Beijing Plain Precipitation Recharge Amount

Beijing is a severe lack of water resources in the region, groundwater is the main source of water in Beijing. Precipitation is the main groundwater in arid and semi-arid regions supply route, particularly more pronounced in the Beijing area, the amount of precipitation on groundwater recharge groundwater recharge up to50percent of the total. With the continuous development of the city, over-exploitation and the deteriorating environment has seriously affected the precipitation infiltration of groundwater recharge, so accurate estimates of precipitation on Beijing groundwater recharge is essential for the development of the city.Infiltration of precipitation WetSpass distributed hydrological model is based on the estimation of the water balance model, it is sufficient to consider a variety of factors such as the impact of climate, soil, land use rainfall infiltration, can be more accurate description because the amount of precipitation on groundwater caused by the change. In this paper, the application of the model, application-related meteorological data, irrigation data, soil data and land use data to estimate the groundwater in2011Beijing plain area of vertical recharge, model validation results show that the study area has better applicability. Then estimate the amount of rainfall recharge2011Beijing plain area, and on this basis to estimate the rainfall recharge coefficient Beijing plain area, as follows:(1) by the average groundwater model simulations2011Beijing plain area of vertical recharge291.1mm (17.63×108m3). By groundwater level dynamic method to validate the results, the results of the vertical plain areas with2011recharge19.59×108m3) of the difference of-2.05×108m3, fruit display, both of which have good spatial correlation, the correlation coefficient R2=80.6%. Verify that the model has good applicability in the study area.(2) to simulate the2011Beijing precipitation Recharge plain area, the average amount of precipitation recharge plain area of233.7mm, total precipitation infiltration recharge area of14.10x108m3. And the use of types and different soil types factors on groundwater recharge for different land. Recharge the smallest known inland water bodies, woodland recharge is relatively high. Because of its characteristics and constraints of the different types of soil infiltration capacity of soil were quite different.(3) Based on the simulated precipitation recharge amount plain areas, GIS computing through space, the estimated rainfall recharge coefficient Beijing plain area. Average precipitation Beijing plain area of recharge coefficient was0.366, compared with the traditional method of calculating the value of an increase of4.0%, little change overall. Conducted a factor analysis of rainfall recharge coefficient in terms of land use, soil type, annual precipitation, evapotranspiration and runoff, such as evaporation.