Mountains around the world provide water for downstream communities. Glaciers and snowpacks store the water, and release it in dry seasons as the snow and ice melts. Glaciers are therefore a water resource, but this water resource is threatened by glacier recession.
Water is essential for life on Earth. Human societies use water to irrigate their fields, generate hydropower, for domestic consumption, and for boiodiversity and wildlife.
Perpetual Planet: Water Towers
The World’s Water Towers were ranked and listed by Immerzeel et al. (2020), with the supply and the demand on each mountain water tower being characterised.
For the study, scientists assessed the water towers’ importance, not only by looking at how much water they store and provide, but also how much mountain water is needed downstream and how vulnerable these systems and communities are to a number of likely changes over the next few decades.
By analysing these various factors of the 78 mountain water towers worldwide, scientists have identified the five most relied-upon systems by continent that should be on the top of regional and global political agendas:
- Asia: Indus, Tarim, Amu Darya, Syr Darya, Ganges-Brahmaputra
- Europe: Rhône, Po, Rhine, Black Sea North Coast, Caspian Sea Coast
- North America: Fraser, Columbia and Northwest United States, Pacific and Arctic Coast, Saskatchewan-Nelson, North America-Colorado
- South America: South Chile, South Argentina, Negro, La Puna region, North Chile
To explore the data in more detail and compare water tower rankings, visit natgeo.com/PerpetualPlanet.
Water Balance App
The Water Balance App could be useful as a front-of-class tool. It shows soil moisture, snow pack, precipitation, evapotranspiration, runoff and change in storage globally and over time. The Water Balance App presents data on the different inputs, outputs and stores of water around the world over the last 20 years.
Students may be able to work through exploring the app on their own, or in a classroom environment. This is an ArcGIS Online app.
There is a ready-made storymap and guide to maximising success at A-Level here.