First, the bad news — Ladakh, a plateau on the northern tip of India, has a major problem. With only four inches of rain a year, this area depends upon winter snow and mountain glaciers for most of its water. But due to climate change, the snow is melting earlier and the glaciers are receding.
In the short run, melting glaciers are something of an advantage; the water supply actually increases. But what happens when the glacier is completely gone?
Sonam Wangchuk, an Indian engineer who had founded an alternative school (https://en.wikipedia.org/wiki/Sonam_Wangchuk_(engineer)), has found a way to store water so it lasts throughout the summer. He noticed how ice in the shade stays frozen much longer. Could that be the clue?
As an engineer, he realized a cone was the perfect shape; it shades its own interior. So one November he and his students routed a mountain stream through a pipe, then turned it vertically with a nozzle at the top. They opened the nozzle at night when the temperature was below freezing and let the spray freeze around the pipe. The eventual result was a cone-shaped mound of ice.
Their first test was 20 feet high with about 40,000 gallons of water; it lasted until May. Now these “ice stupas” can grow to over 100 feet tall, hold up to two million gallons of water, and survive throughout the summer. The eventual goal is to build a stupa so big that when the process starts again the following winter, it will be on a foundation of leftover ice, so the stupa will actually get bigger every year. Think of it as an artificial glacier!
Hopefully, this low-tech solution will provide enough water to safeguard the region’s population.
Sonam Wangchuk explains the concept in this video: https://www.youtube.com/watch?v=7dChiLpYifs
Also see “Making Glaciers in Northern India” by Arati Kumar-Rao in the July, 2020 issue of National Geographic magazine.