A User-Friendly Groundwater Modeling Tool to Inform Decision-Making in Arizona-Sonora Transboundary Aquifers

Abstract

Despite the international socioeconomic importance of transboundary aquifers along the Arizona-Sonora border, they are often understudied and lack sufficient data for complex hydrologic modeling due to geographical, political, economic, legal, and communicative obstacles. Complex models exist for a few basins that have sufficient data, and research on information transfer from data-sufficient basins to data-insufficient basins in the study area has been conducted. However, many basins in the study area remain understudied, and the models that do exist are difficult to access for stakeholders of varying educational and professional backgrounds. The goals of this study are (1) to provide representation for these data- and resource-limited basins, (2) to bridge the gap in communication of model results to stakeholders of varying educational and professional backgrounds, and (3) to provide an easily adaptable template for use in other data-limited regions. These objectives were achieved through the creation of a generic modeling tool that allows stakeholders to access a model ensemble composed of basic conceptualizations of common Southern Arizona aquifer geometries within a regionally appropriate hydrologic parameter space. Within the modeling tool, users can select from two typical basin types to represent the general hydrogeologic structure, boundaries, and parameter ranges of their basin. They can then evaluate their specific basin’s general behavior and response to perturbation using interactive widgets built into a user-friendly Graphical User Interface. The model results are updated in near real time. The Douglas- Agua Prieta basin in Southeastern Arizona was used as an illustrative case of the modeling tool’s abilities and effectiveness. Overall, the modeling tool successfully represented the general behavior of the Douglas-Agua Prieta Basin. A perturbation analysis showed that a decrease in the basin’s mountain-front recharge due to a change in climate toward drier, hotter conditions may lead to an increase in well capture area and, in particular, an increase in streamflow capture by pumping. The modular nature of the tool allows for relatively easy replication for other data-limited regions within and beyond the study area .