Concern has been growing in recent years regarding the potential impact of climate change on Pakistan’s already stressed water resources.Rising temperatures, increasing saltwater intrusion in coastal areas, a growing threat of glacier lake outburst floods, more intense rainfall, and changes in monsoon and winter rainfall patterns are just some of the ways in which climate change is expected to affect Pakistan’s hydrologic resources. These risks amplify an already problematic situation given that Pakistan is among the most water stressed countries in the world. Of particular concern is the potential for climate change to affect water flows within the Indus Basin. The majority of Pakistan’s water is provided through the Indus River and its tributaries, which are fed primarily by snow and ice melt in the Hindu Kush-Karakoram-Himalaya Mountains. Any change in water flow in the Indus basin will have significant implications for food security in Pakistan given that 90 per cent of total agricultural production occurs on arable land supported by the Indus Basin Irrigation System (Qureshi, 2011).Pakistan relies on the largest contiguous irrigation system in the world. Known as the Indus Basin Irrigation System (IBIS) for its basic food security and water supply for all sectors of the economy, it supports the basin comprising the Indus River main stem and its major tributaries—the Kabul, Jhelum, Chenab, Ravi, and Sutlej rivers. IBIS has 3 major multipurpose storage reservoirs, 19 barrages, 12 inter-river link canals, 45 major irrigation canal commands (covering over 18 million hectares), and more than 120,000 watercourses delivering water to farms and other productive uses.Despite increased food production, there has been no change over the past two decades in the estimated 25 percent of the population who are undernourished (FAOSTAT 2012). The National Nutrition Survey 2011 reports that 57 percent of the population does not have food security (Bhutta, 2012). The nival regime generates about 35 to 40 percent of total water flow in the Indus Basin (Immerzeel et al., 2010; Mukhopadhyay&Dutta, 2010; Savoskul&Smakhtin, 2013), which arises from the melting of snow that fell during the preceding winter plus spring precipitation.In contrast to the glacial regime, a consistently negative relationship between runoff and temperature has been reported for the nival regime (Yu et al., 2013; Archer & Fowler, 2008).A higher rate of winter precipitation, which would be consistent with historical trends, could lead to higher levels of summer runoff (Archer & Fowler, 2008; Laghari et al., 2012; Yu et al., 2013).All the changes due to climate change point to a greater risk of flooding during the monsoon season in the coming decades (World Bank, 2013).The studies carried out show that the volume of water flow in the Indus Basin will not change significantly prior to 2050 as decreases in glacial melt runoff will be compensated by runoff generated from increasing monsoon rainfall (Laghari et al., 2012; Shrestha et al., 2015; Yu et al., 2013).The scenario assumes that temperatures increase by 3°C, which would lead to an increase in agricultural water requirements of 6 percent by 2025 and 12 to 15 percent by 2050 (Amir and Habib, 2015). The following graph show the increased demand of water by 2050.
Establish a dedicated water demand research program to better understand future sector demands, potential trade-offs between different water users, specific costing for different water uses and actual water-use patterns. Investigate appropriate water pricing policies that will promote more efficient water useand sustainable management of water infrastructure.Strengthen streamflow monitoring in the Upper and Lower Indus basins.Undertake provincial-level vulnerability assessments to fully understand how climatechange will affect their water resources and the associated socioeconomic consequences. Foster the development of a climate change community of practice in Pakistan.