基于VIC模型的黄河上游冻土水热状态时空演变特征分析OA

To investigate the response characteristics of frozen ground's hydrological elements to climate warming in the plateau region of the upper reaches of the Yellow River,the VIC model was established to simulate the hydrological processes in the plateau watershed of the upper reaches of the Yellow River from 2006 to 2018.The variation characteristics of runoff processes,active layer thickness(ALT),soil moisture(ice)content,and soil temperature in the study area were analyzed.The results show that permafrost can be divided into high-temperature and low-temperature types based on the average annual ground temperature.High-temperature permafrost is more widely distributed,accounting for approximately 70%,while low-temperature permafrost is mainly found in mountainous areas above an altitude of 4 000 meters.The thickening rate of ALT in low-temperature permafrost is higher,indicating a more sensitive response to climate change.The average annual unfrozen moisture content and soil ice content in the upper(0-10 cm),lower(10-30 cm),and deep(30-100 cm)soil layers exhibit a decreasing trend,with the smallest variation observed in the upper soil layer.Significant reductions in unfrozen moisture content and soil ice content are detected in the lower soil layer near Eling Lake and Zhaling Lake.The warming trend at deep soil nodes is relatively stable throughout the year,with a warming rate of approximately 0.02℃/a.The warming trend is more rapid and significant during autumn and winter,when the warming rate reaches 0.03℃/a.