40-Snow Harvesting for Drinking and Irrigation Water - A Case Study.

Abstract

In the recent past due to global warming and change in climate, the snow fall pattern has changed considerably. The late snow fall, frequent avalanche activity and fast snow melting reduces the frequency of contact time and availability of water for recharging to the ground resulting in scarcity of drinking and irrigation water in snow bound regions. Therefore, an attempt has been made to carry out the investigation, design and implementation of low cost structures and their effectiveness for snow harvesting. In this paper a case study of the various techniques used for snow harvesting which is a means to retain snow mass in the formation zone, collect avalanche debris in the middle zone and trap snow melt water are presented.The observation made during winter of 2003-2004 and 2006-2007 are presented here. The snow was successfully retained in a slope of 34°-38°. Studies reveal that the standing snow at harvesting site is more than the general slope and remained for longer duration approxim'ately by 20 days. The mean snow thickness was observed 66 cm for general slope and 77 cm for harvesting site. The snow pit profile of general slope and harvesting site was compared and found that the harvesting site has larger snow layer thickness with higher density than the general slope. The mean standing snow during measurement period of catch dam was observed 275 cm and ablation/week was observed 10 cm for general slope and 23.3 cm for catch darn. The evaluation carried out shows that the measures are very effective.