Monitoring Groundwater Variations from Satellite Gravimetry and Hydrological Models: A Comparison with in-situ Measurements in the Mid-Atlantic Region of the United States
Monitoring Groundwater Variations from Satellite Gravimetry and Hydrological Models: A Comparison with in-situ Measurements in the Mid-Atlantic Region of the United States
复制标题
DOI：
10.3390/rs70100686
复制
发表时间：
2015-01
期刊：
影响因子：
--
通讯作者：
R. Xiao;Xiufeng He;Yonglei Zhang;V. Ferreira;Liang Chang
中科院分区：
文献类型：
--
作者：
R. Xiao;Xiufeng He;Yonglei Zhang;V. Ferreira;Liang Chang
重力恢复与气候实验（GRACE）卫星使命的目的是获取地球重力场的时间变化，其主要内容包括地下水、土壤水分和雪。在这项研究中，SM和累积雪水当量（SWE）模拟的全球陆地数据同化系统（GLDAS）的陆面模式（LSMs），然后用来隔离地下水异常的GRACE派生TWS在宾夕法尼亚州和纽约州的美国大西洋中部地区。利用美国地质调查局地下水气候响应网络2005年1月至2011年12月的监测井水位记录进行验证。对GRACE产品（CSR、GFZ和JPL三个机构）和GLDAS LSM（CLM、NOAH和维克）的不同组合的地下水结果进行了比较和评价。对比分析表明，从GRACE计算得到的三个中心的平均TWS中去除三个LSM的平均模拟SM和SWE得到的解对降低噪声最稳健，从而提高置信度。虽然存在差异，GRACE-GLDAS估计的地下水变化与原位观测基本一致。在95%的置信水平下，月尺度的相关系数达到0.70，差异的RMSE为2.6 cm。双尾Mann-Kendall趋势检验结果表明，在研究期间，该地区没有显着的地下水收益或损失。GRACE时变场解和GLDAS模拟为区域地下水储量变化提供了精确可靠的数据集，在数据匮乏的地区具有重要的应用价值。
Aimed at mapping time variations in the Earth’s gravity field, the Gravity Recovery and Climate Experiment (GRACE) satellite mission is applicable to access terrestrial water storage (TWS), which mainly includes groundwater, soil moisture (SM), and snow. In this study, SM and accumulated snow water equivalent (SWE) are simulated by the Global Land Data Assimilation System (GLDAS) land surface models (LSMs) and then used to isolate groundwater anomalies from GRACE-derived TWS in Pennsylvania and New York States of the Mid-Atlantic region of the United States. The monitoring well water-level records from the U.S. Geological Survey Ground-Water Climate Response Network from January 2005 to December 2011 are used for validation. The groundwater results from different combinations of GRACE products (from three institutions, CSR, GFZ and JPL) and GLDAS LSMs (CLM, NOAH and VIC) are compared and evaluated with in-situ measurements. The intercomparison analysis shows that the solution obtained through removing averaged simulated SM and SWE of the three LSMs from the averaged GRACE-derived TWS of the three centers would be the most robust to reduce the noises, and increase the confidence consequently. Although discrepancy exists, the GRACE-GLDAS estimated groundwater variations generally agree with in-situ observations. For monthly scales, their correlation coefficient reaches 0.70 at 95% confidence level with the RMSE of the differences of 2.6 cm. Two-tailed Mann-Kendall trend test results show that there is no significant groundwater gain or loss in this region over the study period. The GRACE time-variable field solutions and GLDAS simulations provide precise and reliable data sets in illustrating the regional groundwater storage variations, and the application will be meaningful and invaluable when applied to the data-poor regions.