Changes Of Glaciers And Permafrost In Qinghai-tibet Plateau And Their Ecological And Hydrological Effects

The Qinghai-Tibet Plateau(QTP)contains most of the world's mid-low altitude mountain glaciers and permafrost.In recent decades,the climate of the QTP has undergone significant changes,leading to the rapid melting of glaciers and degradation of permafrost in the region,which has changed the regional water cycle and hydrological conditions,and thus changed the natural ecosystem.The QTP has become a hotspot in the study of climate change.In this paper,on the basis of field investigation and theoretical analysis,in three typical areas of the QTP(frozen ground area,glacier area and permafrost degradation zone),using a variety of methods and data,to carry out the cryosphere ecological hydrology related research.The accumulative temperature statistical model was used to calculate the thickness distribution of the active layer and the melting interlayer of the source of the Yellow River.According to the change of the counterclockwise loop relationship between runoff and rainfall,the effect of the degradation of the frozen soil on the change of runoff was identified qualitatively,and the effect of the active layer and the melting interlayer on the control of the runoff was quantitatively evaluated.Based on the analysis of winter runoff,regression coefficient,activity layer,thickness of melt intercalation and the change law of rainfall,on the basis of adopting continuous cross wavelet transform respectively to calculate the source area of winter runoff and regression coefficient,activity layer,thickness of melt intercalation and rainfall similarity,winter runoff are analyzed and four phase correlation in different period.The Spatial Processes in Hydrology(SPHY)model was used to quantitatively calculate the runoff composition and the multi-year variation trend of each component in the typical glaciated area--Yarlung Zangbo River basin.The regional water balance method was used to quantitatively evaluate the contribution of glacier changes to the regional hydrological cycle in combination with remote sensing products.Frost number model is adopted to calculate the QTP permafrost distribution,the QTP is divided into permafrost zone,degradation zone and seasonal permafrost zone,using GIMMS NDVI3 g,rainfall,temperature and maximum melting depth data,combined with a variety of statistics and factor identification method,quantitatively calculated the precipitation,melting temperature and the maximum depth of the contribution of NDVI change on three sub-region.By studying the ecologic and hydrological effects of the changes of the permafrost glaciers,the scientific understanding of the mechanism and influence of the change of the cryosphere has been deepened,and the contents of the cryosphere science have been enriched,providing key scientific basis for the sustainable development of the economy and society in the cold and dry regions.