Assessment of the poroelastic effects of groundwater fluctuations on the California Aqueduct
Abstract
Within the Central Valley, California, a persistent period of drought that started in 2012 was followed suddenly by a wet period from Dec-2016 to Feb-2018 that featured anomalous precipitation events and severe flooding. The ensuing groundwater vacillations are coupled with deformation of the land surface, where land subsidence is linked to aquifer depletion and alternatively, aquifer replenishment with uplift. Infrastructure present on the inconstant surface is subject to deformation-induced stress, which leads to expensive repairs and risks to property.
Flood control structures and aqueducts are particularly vulnerable and vital to maintain, as large populations are reliant on the successful retention and transport of surface water. The California Aqueduct already has lost carrying capacity due to past subsidence, an estimated 20% in some San Joaquin Valley sections, and continued deformation there threatens additional harm. To better understand the dynamics of surface deformation, the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) utilizes L-band radar observations, which provide high resolution ( 7m) data for observing land displacement via repeat-pass interferometry. The evolution of spatial displacement is found by combining multiple interferograms into a time series. To develop a poroelastic model, displacement data is inverted to obtain information about underground properties and processes near the aqueduct. Careful analysis of these patterns helps to reduce risk of socioeconomic hazards and plan for future groundwater resource management.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.G43C0726M
- Keywords:
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- 0994 Instruments and techniques;
- EXPLORATION GEOPHYSICSDE: 1207 Transient deformation;
- GEODESY AND GRAVITYDE: 1211 Non-tectonic deformation;
- GEODESY AND GRAVITYDE: 1872 Time series analysis;
- HYDROLOGY