IMPACT ASSESSMENT OF GORKHA EARTHQUAKE 2015 ON PORTABLE WATER SUPPLY IN KATHMANDU VALLEY: PRELIMINARY ANALYSIS

抄録

 Water security is a concern in the Kathmandu Valley since long era due to the rapidly increased population and urbanization resulting in scarcity and degraded quality of water. Like other sectors, the devastating “Gorkha Earthquake 2015(GE2015)” has certainly impacted water sector. This article aims to assess impacts of GE2015 by analyzing situation of portable water supply, demand and water availability in the area before and after the event and recommend possible development options for sustainable water allocation. SWAT model was applied to estimate the water availability in the surface water source and GDACS recent satellite data analysis was used to estimate the extent of damage from the earthquake. Results showed almost 40% reduction in the amount of water supply after the earthquake affecting additional 0.15 and 0.24 million people under water deficit condition. Harnessing of only 48% and 65% of available surface water during dry and wet seasons, respectively, reveals the potentiality of developing additional water supply projects. However, even with optimal development of surface sources is inadequate to meet the valley's water demand and therefore projects on conjunctive use of surface and groundwater resources, with due care of potential areas for groundwater storage, may be required as a short-term solution to ensure water supply security in the post-GE2015.