Riverbank Erosion is an endemic natural hazard in our country. When rivers enter the mature, they become sluggish and meander or braid. These oscillations cause extreme riverbank erosion. Every year, millions of people of our country are affected by erosion that destroys many kinds of resources such as standing crops, farmland and homestead land, etc. About 5% of the total floodplain of our beloved country is directly affected by this kind of erosion.
Figure-1: Riverbank Erosion in Bangladesh (View1)
The causes of riverbank erosion:
- Flood: Bangladesh is a riverine country. About 700 rivers including tributaries flow through Bangladesh constituting a good waterway of total length around 24,140 kilometers. Most of the country’s land is formed through silt brought by the rivers. In our country, every year the people are affected by floods, especially for a rainy reason. This is the most crucial reason for riverbank erosion.
- Deforestation: Deforestation refers to the cutting down trees and makes a forest non-forest. Trees can hold on the soil aggregates. But when the trees are cut down, the soil particles become loose and for this reason, the soil of the river bank can be eroded gradually.
- Heavy Rainfall: We are in monsoon climate zone. We face heavy rainfall in the rainy season. This extreme rainfall is also an important cause of riverbank erosion. Where there is no well-constructed levee of a river, the soil can be eroded because of heavy rainfall at that time.
Figure-2: Riverbank Erosion in Bangladesh (View2), Credit: KHALIL AHMED SHAMIM
4. Strong Current of the River: Another responsible factor of erosion strong current of the river. The major rivers of our country are Padma, Meghna, Jamuna, etc. There are some specific zones of these rivers where the current of the river water is very much high than the other places. Those places are affected by riverbank erosion badly.
5. Silt Deposition: Deforestation, landslide and other unplanned embankment and destruction of hills for road construction which carried a huge amount of silt in the river beneath by the tributaries of the rivers of Bangladesh. Which result accumulation of silt. This produces the water holding capacity of the rivers. The direction of the river is changed and thus the bank of the rivers is eroded. Silt fence refers to a temporary barrier of woven geotextile fabric that is used on construction sites to help protect streams, rivers, lakes and other aquatic resources and terrestrial resources from contamination by silt, sediment as well as construction debris.
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Figure-3: Riverbank Erosion in Barishal, Bangladesh.
The effects of Riverbank Erosion:
- Displacement of people from one place to another.
- Affect in public health
- Educational structure is also negatively changed
- Affect in the occupation of the affected people
- Unemployment Problems can be increased
- Poverty in society
- Affect in the transport system
- Agricultural demotion
- Losses crops
- Shortage of cropland
- Increase landless labor
- The salinity of land increases
- Isolation from the geographically of eroded areas
- Acquisition of and by government
- Low investment
- Hinder of capital formation
- Affect productivity in eroded Soils
Check out the article: Definition of Soil | The Composition of Soil
In a nutshell, the people of our country are affected because of riverbank erosion every year. The effects can’t be described in a word. The Government of our country and some reputed NGOs should take some immediate steps to reduce the volume of the effects of riverbank erosion. We should conduct some outstanding research projects to find out some awesome findings that can be helpful to improve the socio-economic status of the affected people. Thus we can play an important role in developing our country day by day.
Md. Nayem Hasan Munna
Soil and Environmental Sciences,
The University of Barishal,
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