Identifying dominant human-environmental parameters and robust groundwater planning alternatives in Mexico City
Abstract
Human population growth and urbanization in groundwater-dependent cities has the dual effect of increasing pumping demand while simultaneously decreasing infiltration. In the Mexico City Metropolitan Area (MCMA), groundwater resources supply over 50% of water demand. Land and water use changes in the region have led to massive overdraft and subsidence in the aquifer, threatening the main water source for this metropolitan area, particularly in marginalized communities. Regional-scale, spatially distributed groundwater models have been developed in prior work to test potential future scenarios and policy interventions for this and similar problems globally. However, there is little understanding of how the uncertainties in model parameters influence aquifer management objectives, and how policy interventions perform under such uncertainty. This study evaluates a conjunctive surface water-groundwater planning model for the MCMA using global sensitivity analysis to understand the combined effects of changes in climate, geology, and land use parameters on aquifer management objectives. Combinations of managed aquifer recharge alternatives, including demand management, infiltration of imported water, and reuse of wastewater, are compared using performance indicators to test robustness across the range of uncertain model and scenario parameters. In general, the parameters governing total water use in the basin are found to cause the greatest effects on management objectives. However, geologic parameters such as hydraulic conductivity and specific yield also play a significant role in the performance of the management alternatives, particularly in areas with concentrated groundwater pumping. This study highlights the importance of understanding how individual uncertain parameters and their interactions can affect water supply decision-making processes in densely populated urban areas.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H14H..08M
- Keywords:
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- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 1803 Anthropogenic effects;
- HYDROLOGY;
- 1880 Water management;
- HYDROLOGY;
- 4303 Hydrological;
- NATURAL HAZARDS