Research On The Tibetan Plateau Glaciers Change From Multi-source Data

The Tibetan Plateau is the largest modern glacier region in the middle and low latitude of the world.Under the background of global climate change and world population growth,the glaciers on the Tibetan Plateau is continuously shrinking.Studying the glacial changes on the Tibetan Plateau and understanding the characteristics and trends of glaciers in the region are very important for exploring the relationship between glacial changes and regional natural ecological environment,disaster monitoring and prevention,regional climate change,and global climate change.Based on the background of this research,this paper uses the latest RL-05 monthly gravitational field model from GRACE(Gravity Recovery and Climate Experiment),GLDAS(Global Land Data Assimilation Systems)global hydrological model,and ZY-3 satellite data to carry out glacial changes on the Tibetan Plateau.Research content and results are as follows:1.Using wavelet analysis to decompose and reconstruct C20 items provided by GRACE and SLR.The analysis shows that the C20 provided by SLR has obvious annual change signal compared with GRACE.Therefore,replace the corresponding items in GRACE with C20 items obtained from SLR during GRACE data processing.2.Using regional kernel functions and scale factors to recover signals from surface mass changes in the Tibetan Plateau,the results show that the regional nuclear function can effectively restore the edge signal of the study area;the single factor of scale factor method based on hydrological model can effectively change the amplitude of the regional signal,and the regional kernel function method was used to correct the signal leakage of the glacier mass changes in the Tibetan Plateau.3.Based on the results of surface mass change from GRACE time-variable gravity model with the water balance method,the glaciers mass change on the Tibetan Plateau were obtained.The results show that there are three signal areas in the study area,in which the positive signals of glacial change traverse the hinterland of the Tibetan Plateau with an average rate of change of about 1.3 cm/a.The signals of annual changes in glaciers in the Himalayas and Nyainqentanglha Mountain areas show negative signs,and are accelerated at a rate of approximately 0.8-1.2 cm/a.4.Based on the analysis of the seasonal changes of the glacier mass equivalent water in the eastern Tibetan Plateau,the results show that the equivalent water height of glacier in this area is increasing,and over time,the distribution of profit and loss of glacier mass in north and south regions is reversed,that is,the northern mass of the glaciers turned from loss to profit,and the southern part turned into a loss.This result is consistent with the increasing trend of glaciers in the region.Based on the ZY-3 optical images,the changes of the small glaciers in the eastern Tibetan Plateau were detected.Compared with the three time-phased image data,it was concluded that the glacial edge of the study area showed a significant decrease,and the degree of reduction was gradually reduced year by year,and the increase of glaciers was gradually increased.However,over 95%of the glacier area remains basically unchanged.