Investigating the Relationship Between GPS Elastic Displacements and Hydrologic Storage in Rain and Snow Dominated Watersheds
Abstract
In this study, we examine the elastic vertical displacement of several GPS stations within and surrounding two western watersheds to infer temporal changes in hydrologic loading. Paired analysis of solid Earth deformation in a snow-dominated watershed and a rain-dominated watershed enables exploration of contrasting hydrologic loads and the temporal variability of their seasonal wetting cycles. We find differences in the timing of deformation that correlates with the timing of hydrologic loads between the two watersheds. We further combine GPS-recorded deformation with daily estimates of hydrologic storage for both watersheds to discern the underlying hydrologic processes in each watershed. By leveraging the flexibility of hydrologic bucket models, we show that the hydrologic signal of GPS vertical displacement includes subsurface water storage changes that cannot be explained by soil moisture alone. In conclusion, we demonstrate that comparison of the hydrologic signal within GPS time series and estimates of hydrologic storage can inform how hydrologic storage is partitioned within the subsurface. We suggest that changes in subsurface water storage, which are important for water resources and are challenging to directly measure with hydrologic methods alone, can be inferred from the hydrologic signal of GPS time series.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.G44A..06W