Guwahati, Aug. 5 -- The massive flood in eastern Assam, triggered by heavy rainfall across the region, was worsened by man-made environmental degradation in the hilly terrains of Nagaland. The unprecedented rainfall (up to 137 mm) in Assam, Arunachal Pradesh and Nagaland during July 18-22 swelled all the major rivers in the region, namely the Dikhow, Disang, Darika, Dhansiri, Jhanji and Bhogdoi, carrying a sudden surge of water laden with silt and debris. The volume of muddy water exceeded the capacity of the riverbeds and eventually breached embankments in many places.

The Nagaland government reportedly warned the Assam administration promptly about the possibility of a disaster, but the Assam State Disaster Management Authority probabl...