Multi-Criteria Sensitivity Analysis of the Vulnerability of Hydrologic Systems to Climate Variability and Change in the Southwestern U.S.

Ty Ferré
Posted on: 7/18/2022 - Updated on: 11/07/2023

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Changing climate conditions have been identified as a major threat to the sustainability and availability of water resources in the Southwestern U.S. Long-term decreases in precipitation can lead to reductions in regional groundwater levels and loss of groundwater storage in aquifers for some communities. Reduced precipitation can also lead to lower water levels in streams and losses in the vegetation that grows alongside riverbanks.

The goal of this project was to identify how hydrologic systems in the Southwest might respond to changes in climate and the degree to which this response is dependent on the characteristics of the hydrologic system. To do this, researchers developed a tool that simulates how quickly water moves from the surface to underground aquifers.  The tool helps identify timeframes and regions where seepage of water into aquifers is likely constant, rather than fluctuating with rainfall patterns or climate. By locating these areas upfront, researchers can exclude them from their analysis and focus water supply forecasting efforts on areas where groundwater is more likely to be affected by changes in rainfall or human uses at the surface.

The model shows that areas with a shallower water table tend to have more variability in the rate at which groundwater supplies are replenished, with secondary effects related to the soil type and the period of variation. In these areas, changes in rainfall and water withdrawal for irrigation or urban use have a bigger impact on groundwater availability. Water resource managers can use this tool to more accurately forecast how much groundwater remains in different watersheds and to determine which systems will be most sensitive to changes in climate and water use. The need for better forecasting is only increasing, as aquifers are increasingly tapped and precipitation patterns are expected to become more variable.


Ty Ferré (2014). Final Project Report: Multi-Criteria Sensitivity Analysis of the Vulnerability of Hydrologic Systems to Climate Variability and Change in the Southwestern U.S. 

Affiliated Organizations

The Southwest Climate Adaptation Science Center (SW CASC) was established in 2011 to provide objective scientific information, tools, and techniques that land, water, wildlife, and cultural resource managers and other interested parties can apply to anticipate, monitor, and adapt to climate change impacts in the southwestern United States.

The USGS is a science organization that provides impartial information on the health of our ecosystems and environment, the natural hazards that threaten us, the natural resources we rely on, the impacts of climate and land-use change, and the core science systems that help us provide timely, relevant, and useable information.