Variations of surface water extent and water storage in large river basins: A comparison of different global data sources

International audienceFor the period 2003–2004 and for six large river basins, the present study compares monthly time series of multi-satellite-derived surface water extent with other independent global data sets related to land water dynamics, such as water mass variations monitored by GRACE, simulated surface and total water storage from WGHM, water levels from altimetry, and GPCP precipitation estimates. In general, the datasets show a strong agreement with each other at seasonal timescale. In particular, over the Amazon and the Ganges basins, analysis of seasonal phase differences and hysteresis behavior between surface water extent, water level and storage reveal the complex relations between water extent and storage variations and the different effects of water transport processes within large river basins. The results highlight the value of combining multi-satellite techniques for retrieving surface water storage dynamics