An overview of the effects of urbanization on the quantity and quality of groundwater in South Asian megacities

Abstract

One of the challenges facing megacities in South Asian developing countries in their attempts to realize so-called urban rejuvenation is groundwater conditioned by canal seepage and immense sewage loads. To understand the connection between groundwater pollutants and urbanization, numerous studies were reviewed, and data obtained from a variety of national and international organizations were analyzed. In Delhi and Dhaka, urbanization has lowered the groundwater level as a result of severe overextraction, and its dense population makes Delhi particularly vulnerable to groundwater pollution. In the coastal areas of Karachi and Mumbai, such pollution is magnified by the proximity of seawater as well as the increasing populations of these areas. Among the groundwater pollutants associated with urbanization, chlorides and nitrates are the chief anthropogenic toxins; thus, they are examined in this study. This paper concludes with policy recommendations for minimizing the impact of urbanization on groundwater.