The Causes of Flooding in Bangladesh

1. The Causes of Flooding in Bangladesh Name: • Bangladesh has a high population density due to • people centring around fertile farm land • clustering in the two major urban areas of Dhaka and Chitttagong Background: Bangladesh is a low lying country situated on the delta of the rivers Ganges and Brahmaputra. The country suffered from regular flooding caused by over flowing rivers or by tidal flooding. • Causes of Fluvial Flooding: • Monsoon climate creates high levels of rainfall which swell the rivers. Rainfall up to 2600mm in about 5 months. • Bangladesh is the natural flood plain for the 2 rivers to flood • Increased runoff from the Himalayas due to partial deforestation in the surrounding countries. Deforestation causes less interception so water can enter the system quicker. • The land is only 1 to 6 metres above sea level so water is slow to runoff the area. • The flat flood plain enables the water to easily spread over large areas. • Spring high tides can also prevent water from escaping from the flood plain. • Causes of tidal flooding • As most of the country is 1 to 6 metres above sea level it is at risk of tidal surges. • The strong cyclones in the area surge water up the Bay of Bengal. Example of Tidal Surge Flooding • Summary of why Bangladesh is at Risk • Low lying land at less then 6 metres above sea flood. • Large floodplains enable flood waters to spread out and cover large areas of land quickly. • Strong tidal surges can easily be higher than the land. • Siltation in the rivers decreases their capacity to transport flood water.