Dear Editor,
With the onset of monsoon, flood woe has begun. Are we prepared for flash floods this year? Flooding is bound to happen, when it rains. It comes every year but the devastation has reminded us during flood only. Central Water Commission serving the nation since 1945 kept hollow promises to protect us. But the reason of flood has remained unresolved. After successive failure, Flood Control Board was renamed as Water Resources Department. Assam is geographically situated below the foothills of NE states. It has hills in the surroundings and it carries a huge amount of water to plain. In such a situation, the mighty Brahmaputra cannot contain excessive rain water from its tributaries. Also it is influenced by snow melt from glaciers. Besides it is caused by big dams from China.
Brahmaputra is a trans-boundary river crossing China, India and Bangladesh. The Brahmaputra is well-known for floods, channel shifting and bank erosion. This is due to the fact that most of its tributaries are large, and bring large quantity of sediments owing to heavy rainfall in its catchment area. Traditional sand embankment just can’t protect Assam. But the condition worsens when the river breach its bank. The much awaited construction of road-cum-embankment to save landscape and its ecosystem hasn’t been started. The most important thing for administration is to chalk out plan for flood prone areas so that loss of human life/livestock, damage to property and destruction of crops could be prevented from natural disaster.
Many cities from North East are facing artificial flood every after one rain. Even there are floods in the hill station. Owing to heavy rains, there is huge silting from the hills and it clogged the drains and finally Guwahati roads had silted up resulting flash floods. The unplanned urbanisation and unchecked deforestation have taken a toll.
There has been no significance analysis on the topography of rainfall-depth-duration-frequency on the mighty Brahmaputra that finally led to extreme cases of loss and destruction of flood. The magnitude of aftermath was higher than expected. The nation should take stock of the latest flood situation for flood relief and rehabilitation of flood damage announced.
A research project for long term study on Brahmaputra and its role in creating devastating flood is also required. Neigh-bouring China must share hydrographical study on flood estimation. So far an empirical approach is generally followed for embankment, waterway of bridges/cross drainage structures leading disasters in plains.
Moreover peak discharge of water from dam during monsoon rainfall is never considered. A rational and scientific estimation of floods is the need of the hour for safe and yet economic design of structures. Data collection on rainfall and river discharge is a critical issue.
A landmark study of flood formula on mighty Brahmaputra can be brought out from a joint effort from Central Water Commission, Railways, Roads and Water Resources and Meteorological department with the support of local expert. A final finding must come out this time for this perennial problem that carries a catastrophic effect to NE development.
A master plan to this perennial problem may be initiated with the help of expert in view of the other countries.
Yours,
Kamal Baruah
Guwahati