Climate change impact on groundwater recharge and suggested adaptation strategies for selected Asian cities

Abstract

Climate change impact on groundwater recharge and suggested adaptation strategies for selected Asian cities Currently, 54% of the world's population live in urban areas, and this figure is expected to increase to 66% by 2050. Major cities and municipalities in the region rely either wholly or partially on groundwater. Four Asian cities, namely Bangkok, Bandung, Ho Chi Minh City, and Lahore, are selected for the study as their groundwater dependency is in the critical range of 45% to 100%. Therefore, this study aims to assess current and future climate, quantify changes in climatic drivers, analyse the vulnerability of groundwater recharge systems to such changes, and then formulate adaptation strategies to reduce the vulnerability to groundwater resources in these cities. The methodology includes model-backed analysis of groundwater recharge vulnerability, which is later discussed with stakeholders (policy-makers, scientists, and local water users) to prescribe possible adaptation options. The results show that Ho Chi Minh City and Bandung will receive less rainfall and Lahore and Bangkok more rainfall in the future. Bangkok is the only city in which minor fluctuations in future temperature is observed, while the remainder have significant increases (up to 3.1 °C). In line with the rainfall projections, Ho Chi Minh City and Bandung are projected to experience decreased groundwater recharge while the other two cities, Bangkok and Lahore are expected to have higher groundwater recharge in future. Groundwater, Climate change, Bangkok, Bandung, Ho Chi Minh City, Lahore ABSTRACT KEYWORDS DOI DATES HIGHLIGHTS » The future climate of four Asian cities: Bangkok, Bandung, Ho Chi Minh City (HCMC), and Lahore were projected using multi-climate models » A water balance/hydrological model was developed to simulate groundwater recharge in four Asian cities » Future temperature is projected to increase in all four cities in accordance with global trends » Rainfall in HCMC and Bandung is projected to decrease, whereas it is projected to increase in Bangkok and Lahore » In line with the rainfall patterns, groundwater recharge is expected to decrease in HCMC and Bandung, while projected to increase in Bangkok and Lahore