Impact Analyses of Upstream Water Infrastructure Development Schemes on Downstream Flow and Sediment Discharge and Subsequent Effect on Deltaic Region

Abstract

The lavishness of delta and its ecosystem heavily depends on continuous supply of fresh water flow and sediment flux into deltaic region. Since last few decades, the mighty river contributing a portion of fresh water and deposit sediment into the Delta. The extensive use of fresh water for irrigation purposes and construction of vast network of dams, barrages and associated upstream structures have severely reduced downstream discharge of the Indus River to Sea. The reduced down stream flow has resulted in pronounced sea water intrusion into once the fertile and lush green land of Indus Delta. The decline in the inflow of fresh water has uncovered this composite bionetwork to a number of environmental and social stresses in the form of habitation and biodiversity; reduced in productive values of ecology. The Indus Deltaic region, once occupying an area of about 5000 km2 consisting of creeks, mudflats and mangrove forest is now condensed to 1,192 km2 . While the mangroves cover, once an approximate area of 250,000 to 283,000 hectares till early 1980s drastically declined to 73, 000 hectares in 2006. The resulting destruction of delta is not a problem of its own but death of fishing culture, ecology and destruction of livelihoods of local fishers and peasants.