This article discusses the design and implementation of the Hawai’i Groundwater
Recharge Tool, an application for providing data and analyses of the impacts
of land-cover modifications and changes in precipitation on groundwater-recharge
rates for the island of O’ahu. This application uses simulation data based on a set of
29 land-cover types and 2 precipitation conditions to provide users with real-time
recharge calculations for interactively defined land-cover modifications. The tool provides
two visualizations, representing the land cover for the island and the resultant
groundwater-recharge rates, and a set of metrics indicating the changes to groundwater
recharge for relevant areas to present a set of easily interpretable outcomes based
on user-defined scenarios. Users have varying degrees of control over the granularity
of data input and output, allowing for the quick production of a roughly defined scenario,
or more precise land-cover definitions. These modifications can be exported for
further analysis. Heuristics are used to provide a responsive user interface and performant
integration with the database containing the full set of simulation data. This
tool is designed to provide user-friendly access to the information on the impacts of
land-cover and precipitation changes on groundwater-recharge rates needed to assist
in making data-driven decisions.