利用GRACE RL05模型监测长江流域水储量变化

Monitoring water storage change of Yangtze River basin from GRACE RL05 model

本文基于GRACE最新重力场模型RL05序列研究了高斯滤波、Wiener滤波、各向异性滤波三种方法在长江流域水储量变化监测中的适用性,计算了应用三种方法得到的水储量变化速率。通过与长江流域水文模型的比较,高斯滤波平滑半径为430km时所得的结果与Wiener滤波基本一致,但各向异性滤波反演的结果与水文模型更为接近,并且优于前面两种方法。研究结果表明GRACE RL05时变重力场球谐系数误差存在各向异性的分布特征,因此各向异性滤波更适用于GRACE区域水储量变化的研究。

Based on the latest gravity field model about the series of GRACE RL05, the monitoring applicability of water storage variation of the Yangtze River Basin by three filter methods as Gaussian, Wiener and anisotropic was discussed, and the rates of water storage change by the three ways were calcu- lated. Through the comparison with the Yangtze River hydrological model, it showed that the results could be the same with Wiener filter when Gaussian filter smoothing radius was 430kin, but the inversion results by anisotropic filter would be close to the hydrological model, which was better than the two previ- ous approaches. The research demonstrated that the spherical harmonics errors of time-variable gravity fields observed by GRACE RL05 had the characteristics of anisotropic distribution, thence anisotropic fil- ter would be more applicable to the study of GRACE regional water storage changes.