基于GRACE时变重力场模型研究印度河-恒河流域水储量变化

印度河和恒河是亚洲的重要河流,流经区域也是印度次大陆人口最集中的地区,研究该区域水储量变化对于保障当地生态环境和经济发展有重要意义.本文利用GRACE_RL05时变重力场模型反演2002-2016年的印度河-恒河流域内陆地水储量变化,并结合GLDAS水文模型获取区域地下水储量变化.研究发现:2002-2016年印度河和恒河流域陆地水储量和地下水储量均呈下降趋势,其中两流域的地下水下降的速率(分别为-7.2 mm／a和-4.7 mm／a)超过整体水储量的下降趋势;综合水文模型数据分析表明:该区域水储量下降的原因是蒸发量上升和降水持续减少的背景下,农业灌溉过程中过度抽采地下水导致的. 

A research on water storage changes in the Indus-Ganges river basin based on GRACE time-varying gravity field

The Indus and Ganges rivers are important rivers in Asia,and the two basins the two rivers passed are also the most populous areas in Indian subcontinent.It is of great significance to study the water storage changes in this region to ensure the local ecological environment and economic development.In this paper, the GRACE_RL05 Time-varying gravity field model was used to calculate the change of total water storages of Indus-Ganges River Basin from 2002s to 2016s,and the GLDAS hydrological model was used to calculate the changes of groundwater storages.The study found that,the Total Water Storages (TWS) and Groundwater Water Storages (GWS) of the Indus and Ganges showed a downward trend from 2002s to 2016,and the rate of groundwater decline (respectively-7.2 mm／year and-4.7 mm／year) in both basins exceeded the TWS decline rate.Comprehensive hydrological model data analysis shows that the reason for the decline in water reserves in this area is caused by excessive pumping pipelines in excessive agricultural irrigation against the background of rising evaporation and continuous reduction of precipitation.