Tuesday, July 23, 2013

how "do-it-yourself glacier" can save farmers

Last week, i found a pretty interesting article in The Economist.
Farmers in Kashmir have reduced length of growing period, because glaciers have disappeard. So a team has just rebuilt a glacier to make sure that farmers get their water when it is needed.
A pretty impressive story : just get yourself convinced.

Do-it-yourself glaciers

The iceman cometh

If climate change takes your local glacier away, why not build another?

AS THE climate warms, glaciers shrink. That is a problem for those who rely on meltwater from them to irrigate their crops: farmers living in the valleys above Leh, in Jammu and Kashmir, for example. Most of the lower-lying glaciers in the area they inhabit have disappeared, and those at higher altitudes have retreated by as much 10km (6 miles). The meltwater that farmers need to irrigate their newly sown crops used to arrive in March or April. Now it does not come until June—too late to be of much use in a place with such a short growing season.
Chewang Norphel, a retired civil engineer who lives in the area, thinks he has the answer: if the natural glaciers have gone, why not build artificial ones? That is what, for the past decade or so, he has been doing. Moreover, he has built the new glaciers in places where they will thaw at exactly the right time, and debouch their contents directly onto farmers’ fields.

Based on a Newton-and-the-apple-like moment, when he noticed that a stream in his garden had frozen under the shade of a poplar grove, though elsewhere it flowed freely, he realised that the way to build a glacier is to slow water’s flow and shield it from the sun. And that is what he and his team of engineers are now doing. They have diverted several streams in the worst-affected areas into canals that take long, meandering routes through shady, gently sloping topography. They have also built stone weirs across these canals at regular intervals, to slow the current down still further and encourage water to spill over the canal banks. As the spring thaw sets in and the canals fill up, this overspill freezes into a layer of ice. And as the process repeats itself over the ensuing months, these ice sheets stack up and get thicker.

taken from http://www.hydratelife.org/wp-content/uploads/2012/07/photo-via-gommes-dot-net1.png

So far, Mr Norphel and his team have built a dozen artificial glaciers in this way. The largest of them is a kilometre and a half long and two metres thick. Meltwater from these glaciers helps sustain the livelihood of thousands of farmers. Indeed, because the new glaciers are located where they will be most useful, rather than where the whims of geomorphology dictate, some farms are better-off now than they used to be in the days before the natural glaciers vanished. Land that previously yielded but one crop a year yields two. And water-loving cash crops like willow (whose twigs and branches are used in the area as building material) can be grown.

Picky glaciologists might argue that what Mr Norphel is creating are not, strictly speaking, glaciers. For a body of ice to qualify for glacier status, according to the textbooks, the layers it is made of must, by a process of repeated freezing and thawing, have metamorphosed into a solid block of granular ice. Mr Norphel’s have not—at least, not yet.

This distinction is, however, probably lost on Leh’s farmers. They are just glad to have their meltwater back. And Mr Norphel has identified several other places which might benefit from his technique, including Spiti in Himachal Pradesh, Gilgit-Baltistan over the border in Pakistan, and a number of valleys in Kazakhstan and Kyrgyzstan. In an area where neighbours do not always see eye to eye, the spread of his technique may perhaps put a positive spin on the phrase “diplomatic relations are glacial”.

Note that a film, entitled white knight has been made over Norphel's life.

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