Bangladesh (1998)• Bangladesh is one of the most densely populated countries in the world

• It has a population of 125 million

• Is one of the poorest countries in the world with a GNP of $20

• There are three main rivers passing through the country, and they are called the River Ganges, Meghna and the Brahmaputra

• Experience floods and tropical storms every year as they are by the bay of Bengal which acts as a funnel for cyclones and tropical storms to occur in Bangladesh

Physical Causes

• Most of the country is a huge flood plain and delta of rivers• 70% is less than 1m above sea level• Rivers, lakes and swamps cover 10% of the land• Tropical cyclones bring heavy rain and storm waves from the bay of Bengal which cause coastal

flooding• Snowmelt from the glaciers in the Himalayas in late spring and summer increase discharge of the

rivers• Heavy monsoon rains occur over the Himalayas

Human Causes • Deforestation- The Ganges and the Brahmaputra rivers have their sources in the Nepal and Tibet mountains and in recent years the

rapid population growth has caused the removal of large forest areas.

• In Nepal 50% of the forest has been cut down

• The removal the forest causes a decrease in the amount of interception and an increase in the amount of surface run-off and soil erosion.

• The silt and soil is deposited in the river channels causing the capacity of the river channels to reduce, therefore increasing the risk of flooding

• Dam Building

• Farraka Dam is blamed for the raising of the river bed of a river that leads into the Ganges. During the dry season the dam reduces the discharge of the river encouraging sedimentation on the river bed increasing the risk of flooding

• Global Warming

• The higher sea levels meant that the surface water on the floodplain took longer to infiltrate. Also, the increase of rainfall in the Himalayas and the glaciers melting is down to global temperatures increasing

• Urbanization

• Recent schemes involving the construction of networks of roads and embankments have added obstacles to the free drainage of water from the land

Social Impacts• Over 1000 people were killed and millions made homeless

• 240 villages were submerged

• Shortages of drinking water and food

• Respiratory infections affected large numbers of people and their were outbreaks of cholera and other diseases

• Some people died from snake bites in the flooding

Physical Impacts• Large amounts of silt was deposited which is a positive impact as this is very fertile soil but

deposition in the channel would cause the capacity of the rivers to decrease. The river levels would increase and as it is very lying land this would mean many villages would be under threat.

• The channel would have been widened and deepened, increasing the hydraulic radius of the river• New channels would have been cut open due to the erosion of the soil • Animal’s habitats would have been destroyed• Pollution from the river, some of it toxic would have been spread across the land by the

floodwater.

Economic Impacts• Large amounts of farmland and many properties were washed away

• The cost of the floods was in the region of $1 billion

• 2 million tonnes of rice was destroyed

• 1/2 million cattle and poultry were lost

• Rescue attempts cost money and further damage the economy of Bangladesh

• The floods have meant that many garments factories are running below capacity

• The main highway connecting Dhaka to the rest of the country was flooded isolating the capital

• Infrastructure was destroyed, roads and railways destroyed and electricity supplies affected

• Also, communications became difficult, with shipping impossible in the main port