River conservation in the Indian sub-
B. Gopal with contributions from B. Bose and A.B. Goswami
The Indian sub-continent, lying between 0° and 37°6’N, and 61° and 97°25’E, is a diamond-shaped land mass, bounded to the north by the Great Himalayan arc, and to the south, east and west by deep sea. The Great Himalaya is contiguous on its western side with the Hindukush Ranges that extend in the southwest as the Suleiman and Kirthar Ranges. On the east, the Himalayan arc is represented by the Arakan Yoma Ranges in Myanmar, and the Naga and Garo hills in eastern India. The sub-continent comprises six sovereign nations — India, Pakistan, Nepal, Bhutan, Bangladesh and Sri Lanka — and is unique in the diversity of its geology, climate, vegetation and fauna, as well as human cultures.
The rivers of the region have played a major role in shaping the history of human civilization in the subcontinent. The early agrarian civilizations of Harappa and Mohenjodaro that flourished in the Indus Basin depended upon intensive irrigation which required diversion of river water through an extensive system of canals. Human settlements on the banks of the River Ganga (Ganges) and its tributaries have continued to exist for more than 5000 years. The rivers were extensively used for irrigation, potable water supply, recreation, Ashing and transport. Interestingly, rivers were revered as mothers and worshipped as goddesses. During the past few decades, an exponential increase in human population, rapid urbanization and industrialization, intensive agriculture, and growing demands for energy, have all severely affected the rivers of the region. The regulation of river flows by channelization and dams, and the discharge of domestic and wastewater effluents, have led to a sharp decline in riverine water quality and biological resources. However, while river conservation and management have recently begun to receive some attention, scientific studies are few and are generally confined to hydrology and water quality. This chapter provides only a bird’s eye view of the river systems in the sub-continent, their scientific understanding, the state of their degradation and its causes, and the conservation and management policies and actions in different countries of the region.
Almost all the rivers originating in the Himalayan belt pass through India in their upper and/or middle reaches. They share drainage basins between two or more countries and, hence, also their problems. Like other areas of science, rivers have also received relatively more attention in India than in other countries of the sub-continent. Therefore, this chapter focuses primarily on the Indian rivers.
Extensive information on the geology, geomorphology, climate, soils, water resources, flora and fauna of the Indian sub-continent is available in many publications (e.g. Ahmad, 1951, 1969; Raychaudhuri et al., 1963; Mani, 1974; Robinson, 1976; Fernando, 1985; Cooray 1984; Erb, 1984; Costa and De Silva, 1995); thus only a few salient features are mentioned below.
Global Perspectives on River Conservation: Science. Policy and Practice.
Edited by P.J. Boon, B.R. Davies and G.E. Petts. © 2000 John Wiley & Sons Ltd.