What has caused the increase in disastrous floods, and can't the government do something to mitigate the issue?
Poor or no drainage is one of the main cause of flooding.
Some heavy rainfall (and with some other natural disasters) can also cause flooding. The flood that submerged one third of of Pakistan last year would be beyond drainage. Although some flood would have been avoid if drainages are well constructed and if people are not turning the drainages into a dumping ground.
The one that happened in Southern Nigeria last year was as a result of heavy rainfall and displace of water water from dams in Nigeria and in Cameroon caused it.
Thise are natural disasters.