Basins around the Asian Water Tower benefits more than one billion people in Asia and plays a vital role in global economic development. However， the water resources of the Asian Water Tower have changed dramatically under the background of climate warming. Meanwhile， the water demand of human activities is increasing rapidly. For all that， changes in supply and demand side make the water stress risk more prominent. In order to understand the Current situation and future changes of water stress in basins of the Asian Water Tower， here based on the runoff and water withdrawal data of the global hydrological model in the Inter-Sectoral Impact Model Intercomparison Project （ISIMIP）， the research establishes an index to evaluate the water stress status and possible future changes in 21 basins around the Asian Water Tower. We conclude that the water stress of the 21 basins of the Asian Water Tower showed an overall upward trend during 1971—2010. Especially， the basins with high or above average water stress levels， including Indus， Tarim and Huanghe. In the future scenario， the change of water stress in the 21 basins of the Asian Water Tower will initially increase， and then different basins will show three trends under different scenarios， involving continuous increase （2 basins）， stabilization （5 basins） and decline （14 basins）. Human activities of water withdrawal play a crucial part in the change of future water stress. Among them， the basins in South Asia and Southeast Asia with increasing water stress， such as Brahmaputra and Mekong， water scarcity and security of them pose a significant risk in the future.

Lakes are sensitive indicators of climate change， and studying their dynamic changes was of great significance to reveal global climate change and water resources utilization and management. Based on Landsat-5/7/8 satellites and high-resolution remote sensing images， the temporal and spatial characteristics of lake area change during 1989—2021 in Dorsodong Co-Mitijiangzhanmu Co in source region of the Yangtze River were analyzed， and the response of glacial lake and glacier to climate change was discussed. The results showed that during 1989—2021， the average area of Dorsodong Co-Mitijiangzhanmu Co was 1 011.37 km²， which expanded from 872.07 km² in 1989 to 1 119.5 km² in 2021， with an average expansion rate of 8.62 km²⋅a^-1. In terms of interdecadal variation， the lake area expanded most obviously in the early 21th century， especially in the northern， northwestern and southern parts of the lake. Growth was slowest in the 1990s. From 1990 to 2020， the area of Geladandong Glacier shrank from 797.85 km² in 1990 to 766.19 km² in 2020， a decrease of 31.66 km²， with a reduction rate of 1.106 km²⋅a^-1. Between 2015 and 2022， the glacier area decreased by 19.55 km². From 2005 to 2010， the glacier area decreased by 1.50 km². Glacier retreat accelerated from 0.51 km² in 1990 to 2.20 km² in 2010. Before 2004， glacial meltwater caused by rising temperature was the main factor of Dorsodong Co-Mitijiangzhanmu Co lake area change， with an average contribution of 66.8%. After 2004， precipitation played a leading role in the change of Dorsodong Co-Mitijiangzhanmu Co lake area. The average contribution rate of precipitation to lake area change was 57.8%. Through the analysis of net evaporation， it can be found that the net evaporation of Bangor， Shenza and Amdo all showed a downward trend year by year， especially the net evaporation of Shenza Station showed a significant downward trend， and the decline rate was 7.8 mm⋅a^-1. Therefore， it can be found that the net evaporation of Dorsodong Co-Mitijiangzhanmu Co area decreased， and the lake area also increased with the decrease of evaporation. From the perspective of mass balance and lake water volume change， the correlation between mass balance and lake water volume in Geladandong Glacier was 0.69， indicating that glacier mass loss contributes to the increase of lake water volume. The mass balance of Geladandong Glacier lost the most in 2016， the lake area increased by 16.4% and the lake water volume increased by 3.16 Gt compared with 2000. In 2005， the glacier was in a state of accumulation， the lake area was only 0.67% compared with 2000， and the lake water volume increased by 0.9 Gt compared with 2000. From 2000 to 2004， the lake area expanded by 5.1%， and the glacial meltwater was about 4.56 Gt. From 2005 to 2016， the lake area expanded by 6.9%， and the glacial melt water was about 1.94 Gt. It can be seen that the contribution rate of glacier loss to lake from 2000 to 2004 was about 80%. After 2004， the contribution of glacier loss to lake water volume will reach 40%.

Under freeze-thaw cycle conditions， the water migration in subgrade structure was a pivotal factor contributing to the deformations associated with frost heave and thaw settlement in road structures. Many scholars had confirmed that the phenomenon of water migration and accumulation under the pavement structure layer under freeze-thaw action was widespread， and the action of water vapor migration cannot be ignored. However， there was a lack of quantitative understanding of the study of only water vapor migration， and there was a lack of experimental methods for studying only water vapor migration. At the same time， the outflow of liquid water under the pavement covering layer during the freeze-thaw process was an important reason for the sharp increase of water content in the gravel layer or unsaturated subgrade soil layer at the bottom of the covering layer. At present， there were relatively few studies on the outflow law of liquid water during freeze-thaw cycle. In order to explore the water-heat-vapor migration law of the subgrade structure under the freeze-thaw cycle， the subgrade structure of the actual project was simulated， including pavement structure layer， gravel layer and unsaturated subgrade soil layer， and the water migration test of liquid water and water vapor separation under the freeze-thaw cycle was carried out based on the semi-permeable membrane material. The water migration law under the freeze-thaw cycle was obtained by monitoring the hydrothermal change of the sample， the rise image of fluorescence， the change curve of water replantation and water collection. And the pore structure of soil column， the rate of rise and fall and the temperature gradient and other factors on the water vapor migration and liquid water outflow characteristics. The experimental results showed that the temperature change of a freeze-thaw cycle can be divided into five stages： rapid cooling stage， slow cooling stage， stable freezing stage， rapid heating stage and slow heating stage. Under the action of soil water potential， the water in the Maanobis bottle migrated upward in the soil column in the form of water-vapor mixture， and then changed to the form of water vapor when it reached a certain height. The amount of water vapor migrated at the bottom of the temperature-controlled plate and the crushed rock layer increased linearly during the whole freeze-thaw cycle. The amount of water vapor migration gradually increased with time， indicating that the action of water vapor migration in the process of water accumulation cannot be ignored. The outflow of liquid water from the bottom of the temperature control plate and the gravel layer was mainly concentrated in two stages of the freeze-thaw cycle： the first stage was the cooling stage， mainly condensate water， and the second stage was the melting stage， mainly melt water， which accounts for more than 70% of the outflow of liquid water in a freeze-thaw cycle. The small pore structure of silty clay resulted in water vapor migration mainly affected by volumetric gas holdup. With the increase of moisture content， the water vapor migration tended to decrease. However， sand had large pores， and the water vapor migration was mainly affected by the water vapor diffusion enhancement factor. With the increase of moisture content， the water vapor migration showed an increasing trend. The decrease of cooling rate led to a slow decline of the freezing front and reduced the closed effect of soil freezing on the water vapor migration channel. With the decrease of rising and cooling rate， the water accumulation at the bottom of the temperature control plate and the gravel layer increased. The larger temperature gradient led to the increase of water vapor diffusion coefficient and water vapor density gradient， which will lead to the increase of water vapor migration at the bottom of the temperature control plate and the gravel layer. Based on the above results， it was of great significance to reveal the mechanism of the increase of water content of subgrade soil under the condition of freeze-thaw cycle and the causes of road diseases.