The Hyderabad-based National Remote Sensing Agency in India has built a laser-based system that can predict the gravity of floods and sea surges about six hours before they occur anywhere in the country. The system, called Light Detection and Ranging (Lidar), forecasts the places or locations, which are most likely to get inundated. The system was indigenously built by scientists at NRSA and those from the Council for Industrial Scientific Research.
The system can be used in a variety of situations, including planning urban drainage systems and locating telephone and electricity poles, land-mapping and examining changes in forest cover. Lidar works like a radar that tracks, for example, aircraft. The Lidar system beams pulses of laser light through the atmosphere and catches light reflected by dust and other particles in the air, called aerosols. Information about the areas which would be flooded can be known beforehand because Lidar can accurately ascertain the terrain of the ground.