Himalayan glaciers have receded massively in recent years. Shiva Shankar, a former agriculture professor in Bangalore, fears that this will lead to water shortages in northern India.
 | Dr. K. Shiva Shankar, retired professor of agronomy and forestry, University of Agricultural Sciences, Bangalore |
What is the water situation in India?
Average water consumption around the world is about 53 liters per head per day. In India, we expect to soon have only about 20 liters available per head per day. We have had droughts for a long time, and now with global climate change, things will become even more difficult. The glaciers are receding from the Himalayan Mountains. They are about one fifth the size they were about 60 years ago.
Why are these glaciers so important?
The waters from the Himalayan glaciers provide water for about 70 percent of all the people in Asia. In India, we have three major rivers - the Indus, Ganges, and Brahmaputra – and it is likely that they will drain to small rivers. It will be a very big disaster for India, more than any other country.
In most of northern India, there will be no water. Right now there are floods. The flood area has increased from 25 million hectares to 60 millions hectares in the last 30 years. That is an indication that after the water is draining away, and these will become dry areas. This will happen in less than 30 years. It is a very serious matter.
Already today, irrigation, which has benefited agriculture in India a lot, has become very difficult. Things have changed since the Green Revolution. The rate of agricultural production has come down. Groundwater, which is already scarce, has gone down to 800 feet (240 meters) or even 1,000 feet (300m) in some regions around Bangalore.
 | Picture Gallery (click on the image to start)Find out more about the causes of floods, their impacts, and how to limit their damage (Photo: Reuters) |
What can be done to counter this development?
One major step is to rejuvenate rivers and lakes. They are all filled up with silt, and if we are able to remove this, the flow of water will be greater.
We are also working on rainwater conservation, but this takes a long time. People who are dependent on rainwater cannot store it, because it all drains away and becomes polluted by wastes. We have to stop this. We are trying to do that by storing water in the households. In my house, I have installed a 1,000-liter tank for my personal use. I also recycle my water.
How does rainwater storage for households work?
We already have drainage pipes from the rooftops, but they lead the rainwater into the drainage system. Instead of losing the water, we should collect it, filter it, and store it in 12,000- to 15,000-liters tanks. If we are able to store it during the rainy season, we can use it in the dry months when the water situation is very difficult.
Our problem in Bangalore is not the lack of rain. You just have to compare the water situations in Hamburg and Bangalore to understand this. The amount of rainfall these two cities receive is almost the same, but the distribution pattern is totally different. If you look at Hamburg, you get 50 to 70 liters of rain per square meter per month on average. In Bangalore, all of the 800 liters of annual rainfall per square meter occurs in just about 55 days, whereas in Hamburg it occurs over 300 days or more. In Hamburg, there is little evaporation from the soils, and the tanks are always full, whereas in Bangalore the water drains away almost immediately, taking away all sorts of nutrients from the soil and making our rivers very polluted.
How much does it cost to fit a house with a rainwater storage system?
Fixing the rain harvesting system won’t cost you more than 15,000 rupees (235 euros), but for the storage, construction costs will be very high, about 50,000 to 55,000 rupees (780 to 860 euros) for a 10,000-liter underground tank. So far, less then one percent of all households have such a system, but government will have to help. They already require that new houses have such a system.
Could such systems make up for the loss of water incurred by shrinking glaciers?
No, that is not possible. This is only a very small system to manage water in areas with enough rainfall. In places that depend entirely on water from glaciers, this won’t be enough.
This is not just an Indian problem. The German Aerospace Centre and NASA have studied about 50 river basins in the world to see where and how much water is lost. They found that the river basins of the Congo, Zambezi, and the Nile River are all draining. And in India, the storage capacity of all the basins is going down, as well. Both nationally and internationally, people will really have to think about water.
editor: Thilo Kunzemann
publishing date: March 18, 2008
