Remote sensing technology in India is being increasingly used for a range of tasks, from building highways to predicting landslides.

"Remote sensing technology can provide critical inputs to policy and decision-making in priority areas like food security, water security, environmental conservation, weather and ocean state forecasting and disaster support," said R.R. Navalgund, director of the Hyderabad-based National Remote Sensing Agency (NRSA).

Addressing the 92nd session of the Indian Science Congress here, he said: "With the Indian Earth Observation Programme, the country has a rich constellation of satellites pouring images of one kilometre to one metre resolution.

"In recent years, we have institutionalised our systems into a Decision Support Centre (DSC) at NRSA as an evolving body that collects inputs and disseminates information," he said.

NRSA's data proved useful for the National Highway Authority of India while planning the road link between Bangalore and Mysore.

"With the help of the satellite images, the extension of a two-lane highway into a four-lane one can be planned better by taking into account what land or water bodies need to be cleared," Navalgund said.

Similar data were also under analysis for planning an extension of the railway network to the mountainous terrain of Jammu and Kashmir.

"It is long known that there is a high potential for hydropower generation in the Himalayan regions. With the help of remote sensing technology, NRSA has identified 40 specific sites that should be prioritised for setting up power units," he said.

In recent years, the agency has been analysing satellite images of the pilgrimage routes in Uttaranchal, where landslides are common.

"We have been regularly providing inputs to the state governments in areas of vulnerability. Our predictions turned out to be right during the last monsoon," he said.

Talking to, Navalgund added that the agency was keeping a watch on the Pareechu lake in Tibet in which a large amount of water had led to warnings of an impending disaster in Himachal Pradesh in August 2004.

"A large amount of water is still there. It may get frozen in the winter. What happens in April-May depends on a number of factors. It is a highly inaccessible region, making the task of taking out the water difficult.

"The Indian and Chinese governments will be working on the problem," he said.

While the agency did record detailed images of the destruction brought about by the quake-triggered tsunami waves of Dec 26, Navalgund clarified there was no way of predicting the disaster with the available technology.

The agency similarly mapped the flood damage in Assam and elsewhere in
July-August 2004.