Analysis of current and Future Water Demands in Upper Indus Basin under IPCC Climate and Socio-Economic Scenarios Using a Hydro-Economic WEAP Model.

Abstract

Pakistan is facing severe water scarcity which is further exploited by the increasing population growth and effects of climate change. As climate change is the issue of century and many researchers are working on to find the effects of climate change on hydrological cycle and water scarcity in Pakistan but out those few of them focused their research towards management of water resources under climate change and other external factors. The objective of this research was to develop an integrated water governance strategy to achieve water security for a sustainable future in Upper Indus Basin (UIB) using difference climate change and socio-economic scenarios in hydro-economic WEAP (Water Evaluation and Planning) model. Five sub catchments (Gilgit, Hunza, Shigar, Shyok and Astore) in UIB and UIB were calibrated for the period of 2006-2010 and validated for the period of 2011-2014. For model performance indication, coefficient of determination and Nash Sutcliffe were used. For coefficient of determination, values ranged from 0.81-0.96 for calibration period and 0.85-0.94 for validation period. After setting up the baseline for the model unmet water demands for 2015-2050 was computed for both domestic and agriculture sectors. Scenarios were introduced to assess the effects of climate change and other external factors (Urbanization, Population growth and increase water consumption rate). Results of WEAP model indicated that the unmet water demands for the UIB will reach 134 million cubic meter (mcm) by 2050 for baseline conditions while external driven factors and climate change putting more stress on the water resources. This research further explored the water management options by taking into account the proposed dams by WAPDA (Water and Power Development Authority). These proposed dam (likely to be functional by 2025) will help achieve water security in the basin by decreasing unmet water demand by 60%. Further that, a comparative analysis for different types of future predictions (reference, moderate future-1, moderate future-2 and management scenario) was done to assess the unmet water demands in the UIB. Management scenario reveals that 60% of the water demand coverage will be achieved by 2023, which could help in developing sustainable water governance for the catchment.