基于卫星重力时变重力场的陆地水储量变化研究

Research on the Terrestrial Water Storage Changes Based on Gravity Time-Varying Gravity Field

利用卫星重力技术监测全球陆地水储量变化(TWSC)兼具重要的实用价值和科学研究意义。基于GRACE(Gravity recovery and climate experiment)时变重力场模型研究了2002—2020年全球部分流域水储量变化,并探讨了气候和人为因素对区域水储量变化的影响。研究结果显示:地理区域相近流域的水储量时间序列具有相似的周期和振幅,而位于南北半球的临近流域水储量变化则呈现了相反的周期信号;墨累-达令流域内的水储量受到降水和蒸发共同影响,而印度河-恒河流域由于过度抽取地下水造成流域水储量不断下降;亚马逊流域内的GARCE和GLDAS (Global land data assimilation systems)反演水储量变化的相关性达到0.86,同时发现GRACE在探测区域干旱事件方面有独特的优势。

There are both important practical value and scientific research significance of monitoring the global terrestrial water storage change(TWSC)by satellite gravity technology. Based on the GRACE time-varying gravitational field model, this paper studies the TWSC of global typical river basins from 2002 to 2020, and discusses the influence of climate and human factors on the regional TWSC. The research results show that the TWSC in similar geographic regions have similar cycles and amplitudes, while the TWSC of adjacent watersheds located in the northern and southern hemispheres present opposite periodic signals. The TWSC in the Murray-Darling Basin is affected by precipitation and evaporation, while the Indus-Ganga River Basin has been declining due to excessive groundwater extraction. The correlation between GARCE and GLDAS acquired water storage changes in the Amazon basin reached 0.86. At the same time, it was found that GRACE has a unique advantage in detecting regional drought events.