Temporal And Spatial Variation Of Water Reserves And Meteorological Hydrological Response In China

In recent years,with the impact of climate change and the rapid socio-economic development,China's water shortage and the contradiction between people's needs more and more prominent.Therefore,it is of great economic and social significance to grasp the temporal and spatial variation of land water reserves in China and to study the response relationship between water reserves and meteorological and hydrological factors.With the extensive application of GRACE satellites,it provides a new way to study the change of land water reserves.Based on GRACE,GLDAS and other auxiliary data,this paper analyzes the temporal and spatial characteristics of water reserves in China from 2003 to 2015 by using TheilSen Median trend analysis,Mann-Kendall test and empirical orthogonal function(EOF).Then,linear correlation analysis,partial correlation and complex correlation analysis were used to analyze the response relationship between water reserves and precipitation,evapotranspiration and runoff variation in China.Finally,the drought and flood disaster events are quantitatively described based on the amount of abnormal water reserves and the duration of water reserves.The main conclusions of this paper are as follows:(1)The GRACE Tellus land raster data,which was corrected by the proportional coefficient,found that the details of the change of water reserves in the local area were restored compared with the GLDAS data and the uncorrected GRACE product data.Compared with GRACE and GLDAS data,it can be found that GRACE and GLDAS estimated the water flux variation in most areas of China are very consistent,but because the GLDAS model data lack part of the land water cycle and the model parameters are limited,There are some differences in the local area.(2)Due to the influence of natural and human factors,there are obvious differences in the annual and interannual variations of water reserves in various regions of China.During the year,there are obvious changes in water reserves in the Northeast and QinghaiTibet Plateau Seasonal and interannual changes in northeastern China,northeast China and northern Tibet,the increasing rates were 0.36 cm / a,0.72 cm / a and 0.38 cm / a,respectively.The rate of increase in local area was as high as 2.7cm / a.(3)During the change of water reserves,the effect of precipitation on water reserves is obvious,the variance explanation is 69.2%,and the area of water reserves changes by the hydrological factors is mainly distributed in the wet semi-humid area,In the interannual variation,runoff is the main factor affecting the change of water reserves,the variance interpretation is 62.1%,and the change of water reserves is mainly affected by the hydrological factors.The regional main factors are the main factors affecting the change of water reserves in the southwestern Inner Mongolia Plateau,southwestern Xinjiang and northwestern Gansu Province.Concentrated in the northeast of China,the southeast coast and Guangxi,Guizhou and other places,part of the distribution in the Qinghai-Tibet Plateau and the northwest of the Hokkaido region.(4)The spatial and temporal distribution of water reserves in China during the observation period is characterized by the regional change from west to east,and it is consistent with the gradient of terrain and climate.The correlation between the water storage anomaly index(TWSA)and the spatiotemporal change of the scPDSI drought index in the Songhua River Basin was compared and analyzed,and the GRACE data could be used to identify the water-cold disaster.Based on the abnormal water reserves of GRACE,it can identify the extreme hydrological events,and use the change rate and loss / surplus of water reserves for each month to quantitatively describe the hydrological processes under abnormal water reserves.The results will help the government to prevent flood control and drought Implementation and rational allocation of water resources.