CLIMATE-INDUCED CHANGES TO GROUNDWATER QUALITY IN SOUTH AND SOUTHEAST ASIA

Groundwater is a vital resource in the low-lying deltas of South and Southeast Asia, where hundreds of millions of people rely on water from shallow wells for drinking and irrigation. Deltaic systems in the region consist of some of the world’s largest rivers – such as the Ganges, Brahmaputra and Mekong – which drain the Himalayas, and groundwater hydrology is largely controlled by seasonal fluctuations in river levels. Currently, groundwater quality is spatially variable throughout South and Southeast Asia, and high concentrations of microbial and chemical contaminants (such as arsenic, fluoride, and manganese) are frequently observed. Changes to groundwater flow paths can significantly impact water quality, and consequently, climate-induced changes, including shifts in annual river hydrographs following glacial melting and sea level rise, may impact the sustainability of groundwater resources for domestic and agricultural use. Here I will discuss the key groundwater quality issues of South and Southeast Asia, how climate change may alter existing water quality conditions, and the implications for development and adaptation strategies.