Floods in Bangladesh: due to climatic features
In Bangladesh, at least 10 districts have been affected by severe floods. People are dying, and financial losses are increasing. The Ministry of External Affairs of India has issued a press release regarding this flood situation in Bangladesh. According to the notification, “The flood situation did not arise in Bangladesh due to the release of water from the Indian dam in Tripura’s Gomti River.”
We have seen concern expressed in Bangladesh that the opening of the Dumbur Dam upstream of the Gomti River in Tripura has led to the current situation of flooding in the eastern border districts of Bangladesh. Actually, it is not correct.
The Gomti River catchment area in India and Bangladesh has experienced its heaviest rainfall of the year recently. This flood in Bangladesh is mainly caused by the water of this large catchment on the downstream side of the dam.
Due to geographical location, topography and weather or climatic features, Bangladesh experiences regular floods. There are 405 rivers flow through this country and most major rivers originate outside the country.
When a river flows across more than one country, it is called a transboundary river. The river basins of Bangladesh are Ganges, Brahmaputra and Meghna. They are spread over Bangladesh, India, Bhutan, Nepal and China.
There are 93% of the area of this basin is located in the neighboring countries of Bangladesh. Most of the hilly areas of the country, Madhupur Tract, Lalmai Hills and Barind Tract are flood plains and more than half of them are at an altitude of 8 meters above sea level.
The river water starts to rise due to rainfall under the influence of the south-west monsoon, then if this water rise continues, the low-lying areas like: Haor, Beel, Jheel are filled to the brim with rain water.
So, naturally during the monsoon season, the low-lying areas of the country get flooded due to rainfall. A flood occurs when river water overflows its banks or embankmentss and inundates land, disrupting people’s lives.
The danger level is the height at which water rises enough to damage crops, land, houses, roads, and dams.
There are four types of floods in Bangladesh. The type of flood depends on the nature of rainfall and the level of river flow. One of them is seasonal floods.
Generally, in the month of July-September, the main rivers of Bangladesh and their branches or tributaries gradually increase in water. Then the banks of the river or the adjacent embankments overflow the vast areas.
As a result, floods are seen in those areas. Apart from this, there are flash floods. Sudden floods occur in the north-eastern and south-eastern mountain rivers of the country. The main characteristic of this flood is that the water rises rapidly and recedes rapidly. Heavy to very heavy rainfall in hilly areas causes river water to flow in strong currents.
As a result, such floods caused extensive damage to crops and people’s homes, roads and streets. Many times, people’s lives are lost due to flash floods. Additionally, there are floods caused by rainfall. Such floods are caused by intense long-lasting rainfall and mismanagement of water drainage.
Lately urban areas are prone to flooding due to heavy rainfall. Apart from this, there is coastal flooding. Coastal flooding occurs in coastal lowlands and estuaries in Bangladesh due to tides and cyclones.
Three major river basins of the country play a major role in flooding in Bangladesh. Brahmaputra-Jamuna River water starts rising gradually from June. From the first week of July onwards, the water level of Brahmaputra-Jamuna crossed the danger level.
Then there was flood in the lower areas of Kurigram, Jamalpur, Gaibandha, Sirajganj districts of this basin. Again, at the end of July and in the first half of August the water in the Brahmaputra-Jamuna rises again and the water crosses the danger level and a flood situation occurs.
On the other hand, the water in the Ganga basin started to rise from the second half of July and in August the water crossed the flood limit and flood situation occurred in Chapainawabganj, Rajshahi, Pabna, Kushtia, Rajbari and Faridpur districts.
From April-May, pre-monsoon floods occur due to rise in river water in northeastern Meghna basin area of the country. These floods are also called flash floods and early floods. From June to September in the northeastern region, the rivers Surma, Kushiyara, Manu, Khowai, Kangsha, Jadukata etc. flow over the boundary several times.
Sylhet, Sunamganj, Moulvibazar, Habiganj, Netrokona and Brahmanbaria regions are flooded due to Meghna basin floods. The water of the main rivers of these three basins began to rise simultaneously.
Floods are prolonged and severe when peak flows occur, as occurred in 1988 and 1998. About 61 percent of Bangldesh was flooded in 1988 and about 68 percent in 1998.
According to a report published by the Grantham Research Institute on Climate Change and the Environment and the Center for Climate Change Economics, if global carbon emissions continue and climate change conditions increase,
Bangladesh’s river flow may increase from a minimum of 16 percent to a maximum of 36 percent between 2070 and 2099. The report states that 55-60 percent of Bangladesh is flooded annually, causing around 1 billion dollars in damages.
More than half of the country’s population is at high risk of flooding. As a result, there is a risk of serious humanitarian, economic and environmental crises, the report said.
This problem is deeply rooted in climate change, unpredictable rainfall, intense flash floods, rising sea levels, and melting glaciers.
Studies show that the situation is dramatically worsening due to the drastic effects of climate change. Urgent and major measures are required worldwide to deal with the situation.
