Evaluating the utility of remotely sensed soil moisture for the characterization of runoff response over Canadian watersheds
Citation
Wadsworth, E., Champagne, C., Berg, A.A. (2020). Evaluating the utility of remotely sensed soil moisture for the characterization of runoff response over Canadian watersheds. Canadian Water Resources Journal, [online] 45(1), 77-89. http://dx.doi.org/10.1080/07011784.2019.1691943
Plain language summary
The use of satellite derived soil moisture was examined to determine if it can be used to estimate rainfall-runoff measurements. The rainfall-runoff ratio is the amount of rainfall that stays on the surface after a rainfall event and is closely related to flooding and excess moisture as well as stream flow levels. The soil moisture estimated from satellites was used to see where and when it is most closely related to high rainfall-runoff values through a comparison with values calculated from gridded rainfall and runoff measurements for watersheds across Canada. Regions of strongest correlation were related to the topographic variables of slope and elevation. These results support the use of coarse-scale satellite remote sensing as a valuable data source in hydrological studies, but recommend caution when applying the data to regions where the accuracy of satellite soil moisture data sets is less certain (such as wetlands and areas with high topography) or areas where the runoff generation mechanisms are complex (frozen soils, wetlands or prairie environments).
Abstract
Remotely sensed soil moisture measurements from satellite platforms are increasingly reliable, cost-effective and widely available data sources where in situ measurements are unavailable. This research uses the Soil Moisture and Ocean Salinity mission (SMOS) satellite-derived soil moisture anomalies over a database of 65 watersheds across Canada from 2011 to 2014 to analyze the soil moisture-runoff relationship. A spatial analysis of the variability and influences on the strength of this relationship revealed that 32% of catchments showed significant (1 tailed, p < 0.05) correlations between the weekly antecedent soil moisture state of the catchment and the weekly runoff ratio. Regions of strongest correlation were related to the topographic variables of slope and elevation. These results support the use of coarse-scale satellite remote sensing as a valuable data source in hydrological studies, but recommend caution when applying the data to regions where the accuracy of satellite soil moisture data sets is less certain (such as wetlands and areas with high topography) or areas where the runoff generation mechanisms are complex (frozen soils, wetlands or prairie environments).