Impact of urbanization on Ganga river basin: an overview in the context of natural surface water resources

Abstract

The Ganga river, a symbol of faith for hundreds of millions of Indians, provides all essentials for the development of human beings such as ample amount of freshwater for domestic-agriculture-industrial purposes, productive agricultural land for food production, and diversified flora-fauna for a sustainable ecosystem in its one million km2 basin. Over the years, various alternatives have been introduced in the basin to feed the growing population, and in the last hundred years manifold changes have been made. Various multipurpose dam/barrages were constructed on the river's main stem and on its tributaries for hydropower production, irrigation, and drinking water supply. Similarly, forest cover changed into agricultural land, and barren land was developed for buildings to support housing and industries for an increasingly urban population of the basin. The effects of anthropogenic activities and anthropogenic activity-induced climate change have started to degrade surface water bodies in terms of their quality and quantity, and in some cases, surface water bodies have been lost completely. For example, the major tributaries of the Ganga river in upper part of the basin, Alaknanda and Bhagirathi, had been altered by ~8% and ~35%, respectively, due to dam/barrages. In the Ramganga basin (a major sub-basin of the Ganga river basin), the surface-subsurface water storage was reduced by ~0.2 MCM/km2 during 1982-2013. The increment of lead concentration (Pb, a heavy metal) from 3 μg/L to 26.9 mg/L indicates the influence of anthropogenic activities and human encroachment. The increasing pH (>9) and metal concentration near Kanpur stretches indicate industrialization's impact on water quality. Out of 629 lakes and wetlands, 338 were entirely extinct in the Delhi district. Thus, this chapter enlightens the urbanization impact on the surface water bodies in the Ganga river basin. The chapter also discusses the future research scope from the sustainable development perspective.