Speaker: Dr. Laura Brewington
The objective of this study was to develop an integrated land cover/hydrological modeling framework using remote sensing and geographic information systems (GIS) data, stakeholder input, climate information and projections, and empirical data to estimate future groundwater recharge on the island of Maui, Hawaiʻi. Four future land-cover scenarios and two downscaled climate projections were used to estimate the end of the century mean annual groundwater recharge. The future scenarios focus were (1) conservation, (2) maintaining the status quo, (3) development, and (4) balancing conservation and development. The downscaled climate projections developed were (1) “dry future climate” and (2) “wet future climate.” To understand how the changing land management and climate could influence groundwater recharge, the results were compared to the estimated recharge using the 2017 baseline land cover. The estimated recharge increased island-wide under all future land-cover and climate combinations and was dominated by specific land cover transitions. To better describe the availability of groundwater across Maui, the water-budget modeling framework presented in this study provided information on the “supply” side, while the numerical groundwater modeling approach incorporated the “demand” side. Based on our findings, a spatially explicit scenario planning process and modeling framework would be able to communicate the possible consequences and tradeoff of land cover change under a changing climate, and can serve as a relevant tool for landscape-level management and decision making.