Tuesday, November 30, 2010

THE LOWER INDUS RIVER

Earth Science Search Engine
THE LOWER INDUS RIVER: BALANCING DEVELOPMENT AND MAINTENANCE OF WETLAND ECOSYSTEMS AND DEPENDENT LIVELIHOODS
1. BACKGROUND
Study area: location and geography The Indus River originates at Lake Ngangla Rinco on the Tibetan Plateau and flows3,000 km through mountains, plains of the Thar Desert and deltaic ecosystems to the Arabian Sea. It is the primary source of water for Pakistan. The Indus Delta covers an area of some 5,000 km2, of which 2,000 km2 is a protected area. The fan-shaped Delta is the sixth largest in the world and supports a population of over 130,000 people, whose livelihoods are directly or indirectly dependent on the Indus River.

The water-resource developments
The expanding population, which is growing at a rate 3%, and the extremely low rainfall, has
meant that most areas in Pakistan cannot grow rain-fed crops. With a growing population, the
supply of irrigation water for food production is a top political priority, as is water for industrial and domestic use. Several storage dams and barrages (Box 1) have been built on the Indus River
and a complex network of canals transfers this water to about 30 million acres of agricultural
land. Some dams, e.g. Tarbela Dam, are also used to generate hydroelectric power.

Because of the development drive to meet human needs, decision-makers or water engineers in Pakistan have little experience of the value of aquatic ecosystems and the need for environmental flows. Most see the flow of water to the Delta as an unacceptable loss of water that should be used upstream for irrigated agriculture. Thus the accepted wisdom is to reduce
flows to the Delta. The need for an Environmental Flow Assessment (EFA) The amount of water in the Indus River has decreased dramatically from around 185,000 million m3 per annum in 1892 to 12,300 million m3 per annum in the 1990s (Box 2). The most recent flow was determined by way of the Indus Water Accord in 1994, whereby the allocation of water between the Provinces of Pakistan was decided. The Indus River Authority was established to implement the Accord.


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