Number Theory: How bad are the floods in northeastern states?

Parts of all northeastern states have been affected by floods this monsoon season. But how bad is the situation? Assessing the extent of floods is a long and complicated exercise . However, a part of this problem can be simplified for the North-East since large parts of the populated region in these states are exposed to floods because of overflowing rivers , or fluvial floods. This is different from pluvial floods, which are caused by poor drainage of rainwater. Therefore, the water level in rivers can be a reasonable indicator of the severity of the hazard. Here is what the data shows.