The thick green cover of the upland forests - said to be the water towers - of the North-Eastern states is disappearing at a faster pace than ever before, a phenomenon that has stirred global concerns and activism. Last year marked the International Year of the Mountain. Noted Jawaharlal Nehru University ecologist Prof PS Ramakrishnan led a team of scientists to Cherrapunjee on the southern slopes of Khasi hills in Meghalaya. It is a 70-km-long spur, overlooking the Bangladesh plains, which receives the world's heaviest rainfall but faces acute water shortage several months a year.