Modeling the vulnerability of socio-ecological communities to groundwater shortages during drought at a regional scale
Abstract
Climate change and increasing water demand from expansion of developed land uses and agricultural intensification will place increasing pressure on limited groundwater resources. Particularly during drought, the overexploitation of groundwater can cause drying of both groundwater-dependent ecosystems (GDEs) and shallow domestic drinking water wells, eliminating fish and wildlife populations and leaving communities without a reliable water supply. Preexisting on-the-ground socio-ecological sensitivities--such as where threatened species or disadvantaged communities already are--will predispose certain areas to negative impacts due to their lower adaptive capacity. Thus, broad-scale models of potential groundwater shortages and sensitivities are needed to better understand which areas are most vulnerable and in need of management interventions. In mountainous regions where groundwater basins are heterogeneous and hydrologically separate, such assessments are complicated because regional development trends and species' distributions often operate at scales that overlap multiple basins. This is the case for California's Central Coast, a diverse region with 47 different groundwater basins, many of whom are data deficient. We describe a novel hierarchical statistical model for estimating regional groundwater table response to the combined stressors of development-based water demand (from the LUCAS land-use change model) and drought (from the Basin Characterization Model). We project groundwater elevations during droughts of different magnitude and link these to models estimating the number of shallow domestic wells and GDE habitats that are at risk of desiccation. Finally, we use a hotspot analysis to assess where drying wells and habitats overlap with disadvantaged communities and threatened freshwater species' distributions, to identify areas of highest groundwater vulnerability.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGH13D1071W
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0220 Geomedicine;
- GEOHEALTH;
- 0240 Public health;
- GEOHEALTH;
- 1884 Water supply;
- HYDROLOGY