New inventory of Himalayan glaciers, snow
[KATHMANDU] A new survey of the Hindu Kush Himalayas (HKH) using satellite imagery establishes the extent of the glaciated area of the of the region and helps fill a crucial knowledge gap in the region, referred to as a 'white spot' in data in the Intergovernmental Panel on Climate Change (IPCC)’s 2007 report.
The HKH is home to about a third of the world’s glaciers and the highest peaks, including Mount Everest. An estimated 1.3 billion people living in major Asian river basins downstream, and 25,000 plant and animal species depend on the HKH system.
Reports of the survey, conducted by the International Centre for Integrated Mountain Development (ICIMOD), Kathmandu, were launched on 4 December at the United Nations climate summit in Durban.
The reports indentified 54,000 glaciers, covering 60,000 square kilometres, and a snow cover area of 0.76 million square kilometres, within the ten major river basins in the HKH. These assessments will serve as a baseline for future monitoring and analysis.
"This is the first comprehensive status report of snow cover in the HKH. There was no reference to snow cover in this region in the last IPCC report," noted Deoraj Gurung, remote sensing specialist at ICIMOD.
The last IPCC report had suggested 500,000 square kilometres of glaciated area existed in the Himalayan region – more than eight times the current finding.
"In the past, most scientists from Europe and America would have provided a tentative estimation of 110,000 square kilometres for the HKH region," said Samjwal Ratna Bajracharya, remote sensing specialist at ICIMOD and lead author of the glacier report.
"Now there is no need to estimate since we have gathered the facts," Bajracharya told SciDev.Net.
The glacier status report is a major advance from the last inventory published by ICIMOD and its partner institutes a decade ago, which was based on topographic maps and aerial photographs.
"Topographic maps are secondary sources of data taken by surveyors mostly in winter, when the glaciated area is higher," explained Samjwal Ratna Bajracharya, remote sensing specialist at ICIMOD and lead author of the glacier report.
In comparison, the current inventory is based on satellite images for three years before 2005 and three years afterwards.
The IPCC report had suggested that 500,000 square kilometres of glaciated area existed in the Himalayan region — more than eight times the current finding. "Now we have the facts," Bajracharya told SciDev.Net.
Glaciers were classified according to location, elevation, aspect, thickness and estimated ice reserves.
There are gaps. "We need to analyse the snow water equivalent, which is basically a measure of water in snowmelt, and that is very important for assessing water availability," Gurung said.