ISPRS-Archives ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ISPRS-Archives Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci. 2194-9034 Copernicus Publications Göttingen, Germany 10.5194/isprs-archives-XLII-2-W13-1793-2019 CONVERSE TRENDS OF THE TERRESTRIAL AND GROUND WATER STORAGE CHANGES IN CANADA AND THE UNITED STATES Wang H. 1 2 Xiang L. 1 Steffen H. 3 https://orcid.org/0000-0001-6682-6209 Wu P. 4 https://orcid.org/0000-0001-5812-4928 Jiang L. 1 https://orcid.org/0000-0002-1127-9823 Shen Q. 1 Piretzidis D. 5 Sideris M. G. 5 Hayashi M. 4 https://orcid.org/0000-0003-4890-3113 Jia L. 6 State Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Xudong Street, Wuhan, China University of Chinese Academy of Sciences, Beijing, China Lantmäteriet, 80182 Gävle, Sweden Department of Geoscience, University of Calgary, Calgary T2N 1N4, Canada Department of Geomatics Engineering, University of Calgary, Calgary T2N 1N4, Canada National Earthquake Infrastructure Service, Beijing 100036, China 05 06 2019 XLII-2/W13 1793 1796 Copyright: © 2019 H. Wang et al. 2019 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://isprs-archives.copernicus.org/articles/isprs-archives-XLII-2-W13-1793-2019.html The full text article is available as a PDF file from https://isprs-archives.copernicus.org/articles/isprs-archives-XLII-2-W13-1793-2019.pdf

We study the terrestrial water storage (TWS) and groundwater storage (GWS) changes in Canada and United States. We employ the separation approach from Wang et al. (2013) together with the improved GRACE data of Release 6 for a longer time span until December, 2016. The TWS signals from lake levels are derived from satellite altimetry data over the lakes while TWS signals due to soil moisture (SM) and snow water equivalent (SWE) changes from hydrology models. There are four significant trend anomalies in North America for both TWS and GWS changes. Two positive anomalies are found in Canada with their centers in the provinces of Saskatchewan and Quebec, respectively, due to increased precipitation and/or increased runoff in their surroundings. Two negative anomalies are shown in the United States with their centers in California and the northwest of Texas, respectively, which are due to decreased precipitation and, especially for California, high water usage for agriculture.