ABSTRACT
Moreover, population growth and resultant increased demand of natural resources have disturbed the hydrological regimes of Himalayan headwaters and disrupted the fl ow of primary ecosystem services both in snow and rain fed watersheds (Viriroli and Weingartner 2003). Nevertheless, increasing demand of water in domestic, agriculture, industry, and energy sectors has already stressed water resources, and ongoing hydrological disruptions are likely to cause further increase in water stress and drastic reduction in freshwater availability, particularly during dry summers which will have serious implications for water resources (Singh and Bengtsson 2005). Impact of climatic variability will be particularly considerable in rain-fed agriculture in fragile ecosystems like Himalaya where balance between the availability and demand exists at a very low level with a high vulnerability (IPCC 2007). Further, production of major food crops is likely to decline by 30 percent in India mainly due to increasing water stress arising partly from rising temperature and reduction in number of rainy days creating a very high risk of food insecurity (Aggarwal et al. 2000; Cline 2008; Fischer et al. 2002; Peng et al. 2004). The long-term impacts of changing climatic and environmental conditions would certainly change the conditions for food production in the Himalaya (Aase et al. 2009).
