Floods make a big impact on the environment and society. Floods can destroy drainage systems in cities. Also in cases of severe floods, buildings can be damaged and even destroyed. This can lead to catastrophic events on the environment and society. Floods also cause millions of pounds worth of damage. However, floods do have a slight positive effect on the environment as floods spread sediment-containing nutrients to soil that might never arrive there otherwise.
One example of a river basin that had an impact on the environment and society when it flooded was when Bangladesh suffered one of its worst floods ever, between July and September 1998. Flooding is common in Bangladesh however the floods of 1998 were severe causing over 1000 deaths and 30 million people being made homeless and newspaper headlines were full of headlines of the floods.
The flood was caused by many natural causes; Bangladesh is a very low lying country with 70% of its land area being less than 1m above sea level and 80% of it being flood plain. Bangladesh also had two major rivers running through it (the Ganges and Brahmaputra) this forms a huge delta, both rivers have large volumes of water flowing through them to the sea as they have large drainage basins this increases the flood risk. Bangladesh also has a monsoon climate and the annual torrential rains often results in the rivers overflowing and therefore flooding. The flood was also influenced by many human causes, including the increasing population. Deforestation was also a major cause as it is believed to be responsible for the increased soil erosion, and reducing channel capacity and therefore increasing the likelihood of flooding. Bangladesh is also a LEDC (less economically developed country) and its lack of money and heavy national debt means that little money is available to spend on flood protection methods/defenses.