The water cycle in alpine environments worldwide supplies fresh water to vast downstream areas inhabited by more than half of humanity. The International Network for Alpine Research Catchment Hydrology (INARCH) was launched this year by the Global Energy and Water Exchanges project of the World Climate Research Programme, to improve the predictability of water resources from mountainous regions (see www.usask.ca/inarch).
Melting snow and ice are altering hydrological systems and affecting the quantity and quality of water resources, as indicated in the 2014 Working Group II report by the Intergovernmental Panel on Climate Change. Insight into these processes has been limited by the difficulties of collecting data on the alpine water cycle in high-mountain research areas. Studies have been concentrated at few sites, with poor data comparison across mountainous regions.
INARCH's alpine catchments are well equipped to measure snow and ice hydrology. Such information can be used, for example, to investigate the effects of mountain snowpacks and glaciers on water supply, or to study variations in energy and water exchange in different high-altitude regions. The network will help to develop new observational methods, a measurement infrastructure and an international database to guide research and policy.