2002~2020年刚果河流域陆地水储量变化分析

利用德克萨斯大学空间研究中心（CSR）发布的GRACE时变重力场模型，基于最大信噪比准则确定RL06球谐系数模型（spherical harmonics,SH）的最优高斯滤波半径，在此基础上反演2002-04~2020-05刚果河流域陆地水储量变化，结合水文与降雨、蒸散资料分析其驱动因素。研究结果表明，GRACE模型估计的刚果河流域水储量变化和水文模型估计的地表水储量变化的周年振幅一致，表明刚果河流域的陆地水储量周年变化驱动因素为地表水。对于年际变化，2002-04~2020-05陆地水储量变化呈轻微增加趋势，2002-04~2006-12明显减少，RL06 SH模型估计结果为-2.30±0.24 cm/a；2007-01~2010-12呈现增加趋势，为0.38±0.24 cm/a；2011-01~2020-05水储量增速变大，为0.92±0.12 cm/a，该结果与CSR Mascon估计结果一致。

Analysis on the Terrestrial Water Storage Changes in the Congo River Basin from 2002 to 2020

We use the GRACE time-variable gravity field models released by the University of Texas Space Research Center (CSR) to determine the optimal Gaussian filter radius of the model based on the maximum SNR (signal-to-noise ratio) criterion. Therefore, we use the RL06 SH (spherical harmonics) model to study the TWSC (terrestrial water storage changes) of the Congo river basin from 2002-04 to 2020-05, analyze its spatio-temporal distribution characteristics, and explore the driving factors in combination with hydrological, precipitation and evapotranspiration data. Results show that the TWSC annual signals in the Congo river basin derived from the GRACE model are consistent with those from the land surface water estimated by the hydrological model, which indicates that the driving factor for the annual change of TWS in the Congo River Basin is surface water changes. Withrespect to inter-annual changes, the TWSC during 2002-04-2020-05 slightly increases, but decreases significantly from 2002-04 to 2006-12. The estimated results of RL06 SH models is -2.30±0.24 cm/a; there is an increasing trend from 2007-01 to 2010-12, which was 0.38±0.24 cm/a; The TWS has increased even more rapidly during the period of 2011-01-2020-05, with the trend of 0.92±0.12 cm/a.