Contribution of snow and glacier melt to river flow: Selected upper river basins of the HICAP study, average 1998–2007
Precipitation falls as either snow or rain, depending on the temperature, which is closely linked to elevation. Snow can be stored as long-term (perennial) snow or become ice and contribute to the growth of glaciers. Snow can also be stored in the short term as seasonal snow before melting and turning into runoff. Precipitation falls as rain when temperatures are no longer low enough to form snow. Precipitation in the Hindu Kush Himalayas is dominated by the southwest monsoon in the summer and westerly disturbances in the winter. The premonsoon and monsoon account for 88% of annual precipitation.16 Precipitation varies from 3,000 mm in the eastern Himalayas to 100 mm in the southern plain desert on the western side.17,18 A large proportion of annual precipitation falls as snow, especially at the higher altitudes. The climate of the eastern Himalayas is characterized by the EastAsian and Indian monsoon systems and the bulk of precipitation falls between June and September as monsoon rain. The precipitation intensity shows a strong north-south gradient, as influenced by the mountains. In the Hindu Kush and Karakoram ranges in the west, precipitation patterns are characterized by westerly and south-westerly flows, resulting in a more equal distribution of precipitation throughout the year. In the Karakoram, up to two-thirds of the annual high-altitude precipitation occurs during the winter months.
Year: 2015
From collection: The Himalayan Climate and Water Atlas
Cartographer: Riccardo Pravettoni