Q1.
What is an ice stupa? How is it made, and how does it help the people of Ladakh?
Answer
An ice stupa is a tall, cone-shaped structure of ice built in Ladakh in winter to store water for the dry spring months (Fig. 7.13).
How it is made:
- During winter, water from the mountain streams is channelled downhill through underground pipes.
- The water is then sprayed into the cold air.
- As the spray falls, the extremely low temperature makes it freeze.
- The ice builds up layer by layer, growing into a tall cone — the ice stupa.
How it helps: in spring the streams of Ladakh often dry up, because the heat from the Sun's radiation is not yet enough to melt the snow high on the mountains. The ice stupa melts slowly through the spring, releasing water for farming and other needs right through the summer.
The science inside it: the cone shape is the clever part. A cone has a small surface area for the volume of ice it holds, and its own shadow shields much of it, so the Sun's radiation melts it slowly instead of all at once — exactly when the farmers need the water.
Did you know? The same thinking is behind rainwater harvesting structures and recharge pits used elsewhere in India — catch the water when it is plentiful, store it, and use it when it is scarce.