Study On The Characteristics Of Regional Terrestrial Water Storage And Drought In China Based On GRACE Satellite

Water is the source of life,it is an important part of human survival and life,and is also the key factors influencing the economic and social development.The accurate inversion of terrestrial water resources has already become the urgent needs of the global change research.Based on the gravity satellite as a starting point,proposed by inversion of gravity anomaly value,turned them into the change of the land and water resources quantity,in order to further study the change of land and water resources.Specific studies and conclusions are as follows:(1)In the aspect of data processing:The stripe error of gravity anomaly and water storage change inverted by GRACE(Gravity Recovery And Climate Experiment)satellite are exist,so the spheric harmonic coefficient of gravity satellite has carried on the transformation and a series of preparation,including the replacement of C20.Experiments show that gaussian filtering smoothing can eliminate stripe error,good gravity changes and water reserves are improved.Experiments show that gaussian filtering smoothing can eliminate stripe error,gravity changes and water reserves are all improved.(2)In the aspect of spatial and temporal variations of water storages:China's total land area land water storages present a different spatial trend in 2003 and 2013.The northeast and Midwest terrestrial total water storages present a large continuous increase trend.In the west of three gorges region,including the Yangtze River shelter-forest region,terrestrial water storages showed a trend of fast increase.China's Xinjiang autonomous region almost all showed a trend of decline,of which the most in northwestern Xinjiang.In long-term changes of land surface water storages from 2003 to 2013,Huaihe River and the Yellow River basin shows the tendency of increase year by year,and the trend is concentrated.The change of groundwater calculated by water balance principle,and the.change of the measured.underground site data have very high consistency in months and seasons scale,which proved the accuracy of GRACE inversion.From the perspective of the distribution of groundwater change rate,trend of groundwater appeared downward in the west-north of Xinjiang and the south of Huabei plain.The Yangtze River shelter-forest area of groundwater in a rising trend.(3)In the aspect of water resources time series analysis and the response relationship with precipitation of typical areas of China:The total terrestrial water storages is on the decline in northwestern Xinjiang region during 2003 to 2013,at the same time,the area of land surface water storages also presents overall downward trend.The regional groundwater changes in general can be divided into three stages,presents first increase,then decrease again a steady state.Precipitation with GRACE/Global Land Data Assimilation System(GLDAS)product Data have highest correlation when no lag,with the groundwater has the lag period of 2 months;the total terrestrial water storages the overall upward trend in the Yangtze River shelter-forest region,and the land surface water storages is a declining trend.The change trend of groundwater in the region mainly can be divided into three stages,present smooth after rapid increase,then increase again.Precipitation with GRACE and GLDAS have highest correlation in no lag time,and groundwater deposit one month lag;the total terrestrial water storages and land surface water storages are increased in the south of the north China plain.The shape of the groundwater in the region mainly can be divided into three stages,present first increases,then sharply declined,and growth trend.Precipitation with GRACE and GLDAS have highest correlation in no lag time,and groundwater is a month of lag.(4)In the aspect of comparison analysis between Standardized Water Storage Index(SWSI)and Standardized Precipitation Index(SPI):SWSI can more accurately reflect the drought event,and the low value area of SWSI is continuous.In addition,SWSI relative to the SPI has more volatile between high-value area and low-value area,and more obvious.According to the contrastive analysis of the existing drought event,both in Xinjiang,the Yangtze River shelter-forest and southern of north China plain,SWSI can be more clearly reflect the drought event,and using a GRACE satellite monitoring drought event has more accurate than SPI.