Three-parameter-based streamflow elasticity model: application to MOPEX basins in the USA at annual and seasonal scales

We present a three-parameter streamflow elasticity model as a function of precipitation, potential evaporation, and change in groundwater storage applicable at both seasonal and annual scales. The model was applied to 245 Model Parameter Estimation Experiment (MOPEX) basins spread across the continental USA. The analysis of the modified equation at annual and seasonal scales indicated that the groundwater and surface water storage change contributes significantly to the streamflow elasticity. Overall, in case of annual as well as seasonal water balances, precipitation has higher elasticity values when compared to both potential evapotranspiration and storage changes. The streamflow elasticities show significant nonlinear associations with the climate conditions of the catchments indicating a complex interplay between elasticities and climate variables with substantial seasonal variations.