Sub Himalayan northern West Bengal under high sedimentation risk

SILIGURI: In contrast with southern half of West Bengal, suffering from shortage of rainfall, the Sub Himalayan region in northern half of the state has recorded around 15% higher than normal rainfall, highest in the country this monsoon. But, the rivers at foothills, badly suffering form high sedimentation and thus unable to carry heavy hydroload, have started putting vast forest, agro and tea land under trouble.

As reported, South Bengal had around 30% lesser than normal rainfall this monsoon till 16 thJuly.

Against this, "Sikkim and Sub Himalayan West Bengal have received around 15% higher than long duration average rainfall. Percentile difference between rainfall this monsoon and long duration average of this region is the highest in country," said senior meteorologist Mr. G N Raha form Sikkim.

But, instead of making north Bengal happy, heavy water flow has put north Bengal under trouble. Many major rives were put under red alert, units of National Disaster Rescue Force have arrived, relocation of people have been started.

But more importantly, u ncontrolled human activities, in hills are causing loosening of the top soil. These cause landslide and increased discharge of sand, stone and debris to be carried out by water flow to the downstream foothills. Deposition of these increases height of river beds and thus reduces water retaining capacity. Now after every heavy downpour, water overflows these rivers and covers vast areas of forest, tea or agro land with sand making them sterile- explained eminent geologist Dr. S Sarkar.

"Deep within Buxa Tiger Reserve(BTR) core area, river beds are going up at even 25cm per year rate and we are loosing forest land," said Mr. L G Lepcha, Ex. Field Director of BTR. The picture is same with many other reserved or unreserved forests.

Satellite images revels that over 25% of agriculture land surface in north Bengal foothills is now under sand cover threat. "Many tea gardens have already lost huge area of productive land. But Government is silent," complained planters.

As a remedial measure, Dr Sarkar said, " To have a truly effective and long term result, we must allow the rivers to take their own course by withdrawing all human interferences as best as possible."