Extreme snowfall event analysis and its impacts on agriculture and horticultural crops in western Himalaya, India

摘要

Glaciers and snow are the important features of hydrological cycle and affect volume, variability and water quality in areas where these occur. Snow supplies more than half of water used for irrigation in Himachal Pradesh and other northern states of India and is an important contributor to hydropower and irrigation reservoirs. The fact that snow acts as water storage over the winter and provides soil moisture recharge in the spring is of particular importance to agriculture productivity in mountainous regions. The study on snowfall estimation during 2004-05 in Himachal Pradesh was carried out using remote sensing techniques and ground truth data to estimate total snowfall and assess the impact of snow fall on water availability and crop productivity. The snowfall estimates using remote sensing techniques for two periods by using two sets of imageries before snow fall (October, 2004) and after snowfall (May 2005). This indicated an increase of 28.7 per cent in snow cover compared to pre snowfall period. The ground data from 22 sites also indicated an increase of more than 50 per cent higher amount of snowfall during 2004-05 compared to last two decades. The area under different crops during rabi 2004 was found to be increased by 8.57 per cent, whereas, subsequent kharif season registered 1.85 per cent reduction in cropped area. The increase also reflected in higher productivity during rabi season 2004 and kharif 2005. The productivity of total food grains increased by more than 19.0 per cent during 2004-05 compared to 2003-04. The apple and other fruits registered 12.1 and 59.8 per cent higher productivity, respectively in 2004-05 compared to 2002-03 and 2003-04. The impact of extreme snow fall was more pronounced in short duration vegetables crops. The total vegetables arrivals in the market increased by 48.33 per cent during 2004-05 compared to last three year arrivals. This indicated that there was a positive and significant effect of heavy snowfall on agricultur