Introduction

EVALUATING THE EFFECTS OF FUTURE CLIMATE AND LAND-COVER CONDITIONS ON GROUNDWATER RESOURCES FOR THE ISLAND OF MAUI, HAWAI‘IDate: April 23, 2019

EVALUATING THE EFFECTS OF FUTURE CLIMATE AND LAND-COVER CONDITIONS ON GROUNDWATER RESOURCES FOR THE ISLAND OF MAUI, HAWAI‘IDate: April 23, 2019

Speaker(s): Drs. Victoria Keener, Laura Brewington, and Alan Mair

Part I. Participatory Scenario Planning for Climate Change Adaptation: Projected Future Climate and Stakeholder-Defined Land-Cover Scenarios for the Island of Maui, Hawai‘i —Victoria Keener and Laura Brewington (East-West Center & NOAA Pacific Regional Integrated Sciences & Assessments)

Abstract: For the last century, the island of Maui has been the center of environmental, agricultural, and legal conflict with respect to both surface and groundwater allocation. Planning for sustainable future freshwater supply in Hawai‘i requires adaptive policies and decision-making that emphasizes private and public partnerships and knowledge transfer between scientists and non-scientists. To quantify future changes in an island-scale climate and groundwater recharge under different land uses, we will discuss downscaled dynamical and statistical future climate projects used in a participatory scenario building process. The participatory scenario planning began in 2012, bringing together a diverse group of ~100 decision-makers in government, watershed restoration, agriculture, and conservation to (1) determine the type of information they would find helpful in planning for climate change, and (2) develop a set of nested scenarios that represent alternative climate and management futures. This integration of knowledge is an iterative process, resulting in flexible and transparent narratives of complex futures comprised of information at multiple scales. We will present an overview of the downscaling, scenario building, and stakeholder response.

Part II. Groundwater Recharge for Projected Future Climate and Stakeholder-Defined Land-Cover Scenarios for the Island of Maui, Hawai‘i —Alan Mair (USGS Pacific Islands Water Science Center)

Abstract: Groundwater availability on Maui can be affected by changes in climate and land cover. To evaluate the availability of fresh groundwater under projected future climate and stakeholder-defined land-cover conditions, estimates of groundwater recharge are needed. As such, a water-budget model developed by the U.S. Geological Survey was used to estimate the spatial distribution of recharge for 11 unique combinations of climate and land-cover conditions. A variety of available research material was used in this study to represent the diversity of conditions, including two sets of end-of-century climate projects developed by University of Hawai‘i researchers, and future land-cover scenarios developed by Pacific RISA researchers. In one combination of climate and land-cover conditions, the results of the water budget for two future climate scenarios indicated a decrease across central and leeward areas of Maui, increases across windward areas of Haleakala, and opposing changes for the remaining parts of Maui. The projected changes in recharge for the future land-cover scenarios do suggest that appropriate land management may help to mitigate the effects of a drying climate.