My thoughts and opinions | 9th Sep 2024
Although Bangladesh’s flat and low-lying deltaic landscape, large river systems, and predictable monsoon seasons have made it quite famous, the country also faces severe flooding situations—mostly reoccurring natural disasters. Such repetitive flooding disasters seriously impact millions of people, agriculture, infrastructure, and the economy. Understanding of the causes of flooding in Bangladesh would therefore help consider effective ways of combating the impacts.
1. Geographic and Topographical factors:
O Bangladesh is a deltaic country at the confluence of the world’s largest mighty rivers, namely the Ganges, Brahmaputra, and Meghna. These three mighty rivers form the lifeline of the drainage system of the entire region that also includes a larger part of India. Because it is low-lying and flat, it is susceptible to river flooding.
O These vast floodplains, which make up about 80% of the country, are highly vulnerable to floods triggered by heavy rainfall or water surges carrying water from upstream.
2. Monsoon Rains and Cyclones:
O Monsoon rains, very heavy in Bangladesh from June to October, occur over a period and can raise river levels considerably and also cause floods. Climate change has led to fiercer and more erratic monsoons, and flooding has become much more frequent and severe.
O This flooding situation is further deepened by the occurrence of cyclones and storm surges, particularly along the coasts. High tides and strong winds push the seawater into the land, flooding the existing drainage facilities.
3. Glacial Melting:
O The glaciers in the Himalayas melt and send the water downstream through the rivers into Bangladesh. Glacier melting due to global warming has also resulted in an increase in river flow, posing a high risk of flooding in the spring and summer seasons.
4. Deforestation and Land Use Changes:
O The rate at which the upstream lands were deforested, particularly the regions of India and Nepal, greatly affected the capacity of water absorption from the soil. As a result, a significant amount of runoff finds its way into rivers. This inorganic imbalance also leads to the riverbed siltation, which decreases the effective flow of running waters.
5. Urbanization and Poor Drainage:
O Urbanisation process such as in Dhaka city lead to poor drainage system because growth and mushrooming of cities results in a condition of unplanned development causing urban flooding. Encroachment of water bodies, canals, and wetlands reduces their natural tendency to retain and drain water and causes widespread waterlogging during heavy rainfall.
6. Siltation of Rivers:
O Sediment deposition in rivers and waterways may lead to the reduction in depth and discharge capacity of rivers, with a consequent outburst of water during flood periods. An important factor contributing to this problem is the sediment load from upstream, particularly during the monsoon season when the water flow is at its highest.
7. Human Activities:
O Projects like construction of dam, barrages, and embankments, sometimes carried out without proper environmental assessments, do influence the natural flow of water by acting as guarantors in some ways, in case of floods or otherwise.
Immediate and long-term Strategies to deal with flood impacts in Bangladesh
Immediate Strategies:
1. Better Forecasting and Early Warning System against Floods:
O Enhanced accuracy and extent of early warning of floods and prediction systems may provide vital time for evacuation and preparedness, so that less number of human lives are put at risk and valuable resources are spared.
O Investment in state-of-the-art technologies such as satellite monitoring and weather radars, coupled with hydrological modelling, would significantly help make flood predictions more accurate.
2. Embankments and Dykes Must Be Strengthened:
O To ensure least flooding in rivers and guaranteed safety of towns that are always at high risk of getting submerged under water, repairing and strengthening the dams, dykes, and levees must be done without any delay.
O Temporary barriers to flood along with sandbag reinforcement in critical areas are also proven effective during extreme heavy floods.
3. Response and Relief:
O Communities affected by floods immediately receive rapid response units, emergency shelters, food, clean water, and medical supplies.
O This requires support from community-based organizations and local volunteers.
4. Drainage Maintenance:
O Desilting canals and rivers will help provide better water flow through the system, reducing city flooding. Tackling promptly urban drainage systems can also reduce impact during critical, intense rainfall.
Long-term Measures:
1. Integrated Water Resource Management (IWRM):
O Integrated water resource management planning, which includes the whole river basin, can be an effective measure to increase efficiency of water resource use. For instance, controlling the water flow and river management systems can effectively establish cooperation between the neighbouring nations of India, Nepal, and Bhutan.
2. Reforestation and Afforestation:
O Extensive reforestation and afforestation campaigns should be implemented in the headwaters to increase the soil’s capacity of holding water, decrease overland flow, and prevent depositing sediments in the rivers.
O Conserving and rehabilitating natural floodplains and wetland areas provide a strong line of defence against flooding in the locality.
3. Sustainable Urban Planning:
O Effective reduction of flood risks in cities can be possible through an environmentally sound urban design. Effective urban design, therefore, includes good drainage systems, water body conservation and public open spaces.
O We have been implementing zoning legislation and by-laws to avoiding development in or encroachment along natural watercourses and flood-prone zones.
4. Climate Change Adaptation:
O Developing and implementing strategies to adapt to climate change, which increases the likelihood of flooding, involves building infrastructure, constructing flood-resistant structures, and implementing flood-tolerant agricultural practices. It requires significant investment in research and development to develop new and improved methods for effectively responding to the dynamic conditions of the environment. Such means include flood-resistant crops and water-dependent dwelling units.
5. Dredging of Rivers and Management of Silt:
O Rivers and water courses must be regularly dredged to ensure their storage and depth to minimize chances of overtopping.
O Sustainable silt management practices should maintain a natural balance of sediment movement and avoid excessive siltation.
6. Community Awareness and Capacity building:
O The awareness of the communities regarding flood hazards, preparedness actions and evacuation schemes can go a long way in building the needed resilience. Community-based disaster management programs ensure that the local people are equipped to respond in times of need, such as flood events.
O Training local government units and community leaders in DRRM strategies makes the community at the local level to always be ready to manage flood-related disasters.
7. International Cooperation:
O Regional cooperation strengthened with agreements signed with neighbouring countries for joint management of rivers and coordinated flood protection measures will dramatically reduce the risk of flooding.
O International forums to extract finance and technical assistance will pay rich dividends for Bangladesh to manage the impact of flooding.
Conclusion
Bangladesh is experiencing a strange problem of flooding, which is the result of both natural and human factors. Quick actions can ensure swift relief, but long-term and sustainable remedies will come from proper planning, involvement of the community, and working with international agencies. An altogether integrated approach to the problem focussing on its causes, vulnerability reduction, and adaptation to climate changes is likely to be the key in reducing the frequency and potential impact of floods in Bangladesh.