Indus River Basin Wetlands

Abstract

The Indus Basin extends over 1,120,000 km² in total, straddling four countries: Pakistan (47% of basin), India (39%), China (8%), and Afghanistan (6%). Among transboundary basins, the Indus Basin is notable for its sizable population of about 250 million in 2013. This heightens the importance of its wetlands to natural resource-dependent communities. Wetlands of the Indus Basin, spanning the Tibetan Himalaya to the Arabian Sea, may be categorized as upland (alpine and piedmont), midland (floodplain, terrace, and valley), and low-lying (lacustrine and riverine) wetlands. The wetlands run alongside the Indus River and its numerous tributaries, 27 of which lie above Guddu Barrage. They include significant natural and man-made wetlands supplying subsistence, commercial, and ecological services to human settlements. In the Pakistan portion of the Indus Basin alone, there exist about 225 nationally significant wetlands, of which 15 are Ramsar Sites. The Upper Indus Basin has two sub-basins divided by the Indus River, the Kohat sub-basin to the west and the Potwar sub-basin to the east. Similarly, the Lower Indus Basin comprises the central and southern sub-basins. A third of the Upper Indus Basin lies above 5,000 m a.s.l. Here, the Indus River has its source in the Tibetan Himalaya, before it crosses alluvial plains and reaches its delta on the Arabian Sea. The Basin’s hydrology relies on snow, glacial melt, rainwater, and runoff. Its estimated annual flow is 207 billion m³. The basin supplies a number of anthropogenic ecosystem services, among the most important of which are water supply to large cities, power generation, and food production. However, agricultural ecosystem functioning for food supply in the basin is threatened by rapid population growth, groundwater overexploitation, waterlogging, soil salinization, and inefficiencies in water transport and storage. Irrigated agriculture is estimated to account for 53% of the Indus Basin’s total evapotranspiration.