Glacier mass balance estimation in Garhwal Himalaya using improved accumulation area ratio method

Water requirements of the mountain communities living in the Himalaya are supported by snow and glacier melt. The availability of water from the source depends on numerous climatic and glacier parameters. One key parameter is mass balance, which helps to assess the glacier health and future water availability. We have used the improved accumulation area ratio (IAAR) method to estimate mass balance in Alaknanda and Bhagirathi basins, constituting 1055 glaciers covering ~1609 km2. The mean Equilibrium Line Altitude (ELA) of the Alaknanda and Bhagirathi basins are estimated as 6147 ± 130 and 5985 ± 130 m.a.s.l, respectively. The mass balance is estimated using the accumulation area ratio (AAR)–mass balance relationship. The mean specific mass balance of the Alaknanda and Bhagirathi for 2001–2013 is estimated as −1.1 ± 0.03 m.w.e.a−1 and −1.01 ± 0.07 m.w.e.a−1, respectively. Total mass loss from the study area is calculated as ~21.4 ± 1.1Gt during this period. The loss of glaciers in the mountain area will increase the vulnerability of communities living in the region. It suggests a need for better adaptation strategies to improve the resilience of high mountain communities.