Bangladesh Flood Causes
Bangladesh lies across a huge river delta that contains many distributaries of the Ganges and Brahmaputra, so there is an increased flow of river water in the country. At the time, snow on the Himalayas was melting at an increasing rate due to global warming, which added water to the Ganges and Brahmaputra rivers that flow through Bangladesh. The monsoon rains were exceptionally heavy that year from July onwards. Also, most of the country’s elevation is less than 5 metres above sea level, meaning that the water level does not need to rise by a lot to trigger a flood.
The drainage basins that feed Bangladesh are huge and even span other countries, so the precipitation in these areas that surround Bangladesh still end up inside the country. Deforestation reduces interception by trees and soil storage, resulting in significantly more surface runoff water following a period of precipitation.
The Ganges was diverted to fields of crops for the purpose of feeding them, but this affected the river's floods downstream due to the removal of silt as a result of the diversion. Without silt deposits, the river did not build up the floodplain.
The construction of over 100'000 wells to supply the country's increasing demand of fresh water, due to significant population growth, lowered the water table and caused the land to sink at 2.5 cm a year.
Many of the existing protection measures are faulty, and with the country in dept, corruption resulting in losses of money and private investors not interested in flood protection, improved protection measures could not be afforded.