Coping with climate change in a tropical karst island: Assessment of groundwater resources under HadCM3-GCM scenarios and proposed adaptive strategies

Abstract

Embracing appropriate management strategies to ensure the sustainability of groundwater resource under climate is decisive for tropical karst islands. In this study, long term impacts of climate variability on groundwater recharge and discharge at the Oemau spring, Rote Island, Indonesia using HadCM3-GCM predictor variables for the H3A2a and H3B2a climate scenarios were investigated. The analysis suggests that the sustainability of groundwater resources generally varies over the period and will be adversely affected by climate change during dry years when the area is projected to experience supply shortage of around 29-67 L/s as a result of 5.24-23.63% decrease of rainfall, 2.48-24.57% reduction of recharge, and 2.53-22.80% decrease of spring discharge, under HadCM3 GCM scenarios. A subsequent comprehensive set of management strategies as palliative and adaptive efforts was proposed to be implemented by relevant stakeholders to assist the community dealing with water deficit during the dry years.