Publication Date:
2014-07-06
Description:
The wetness of a watershed determines its response to precipitation, leading to variability in flood generation. The importance of total water storage - which includes snow, surface water, soil moisture and groundwater - for the predisposition of a region to flooding is less clear, in part because such comprehensive observations are rarely available. Here we demonstrate that basin-scale estimates of water storage derived from satellite observations of time-variable gravity can be used to characterize regional flood potential and may ultimately result in longer lead times in flood warnings. We use a case study of the catastrophic 2011 Missouri River floods to establish a relationship between river discharge, as measured by gauge stations, and basin-wide water storage, as measured remotely by NASA's Gravity Recovery and Climate Experiment (GRACE) mission. Applying a time-lagged autoregressive model of river discharge, we show that the inclusion of GRACE-based total water storage information allows us to assess the predisposition of a river basin to flooding as much as 5-11 months in advance. Additional case studies of flood events in the Columbia River and Indus River basins further illustrate that longer lead-time flood prediction requires accurate information on the complete hydrologic state of a river basin. © 2014 Macmillan Publishers Limited.
Print ISSN:
1752-0894
Electronic ISSN:
1752-0908
Topics:
Geosciences
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