Disaster Prevention

Bangladesh is a land of perennial floods and its image is that of a country which is always flooded. It is washed by the Ganges-Brahmaputra and Meghna river system. They combine to form the world's third largest river, the lower Meghna the monsoon spillage is so high that it regularly overflows the banks.

About 20 per cent of the country is regularly inundated which is considered benign as it maintains soil fertility, floodplain fishlands and bio-diversity. Even, severe periodic flooding is common. Since 1954, flooding has covered 37 per cent of the land once every 10 years. The highest was in 1988 when 62 per cent of the land was inundated. In 1987, it was forty per cent. Data also shows that notwithstanding 1987, 1988, 1995 and 1996, there is a declining trend in flood intensity.

Extensive floods greatly affect the marginal population who lose whatever assets they have and suffer from lack of work and wages. People who live in perennial flooded zones, whether in Haor (tectonic deppression) areas or in the Kurigram Jamalpur Sirajganj belt in the north, have low indicators in all sectors of health, nutrition and education. Floods also contribute to the concentration of landownership due to distress sale by the poor in the post-flood situation to the cash heavy people. This is observed in all areas subject to natural disasters. They seem to serve as an imbalancing factor in society.

While this maybe true, there are field reports that the quality of water is rapidly declining and the silt carrying floods-the soil fertilizer-are now carrying more sands which often cover entire fields making them useless for cultivation.

Flash floods cause serious damage to crops, property fish stock and other resources particularly in the north, north-east and eastern part of the country.

The worst flood in history: The flood of 1998 is considered the worst in the natural history of Bangladesh until the end of the century past. The floodwater camped for more than two months in the terrain leading to serious damage. A number of factors were said to be responsible for the flood. July was the warmest month in 118 years, which experts believe Was a causative link.

Experts say that floods were always more severe when the temperature was high. Many said global warming contributed to the severe flood. However, natural phenomenon also played a role. El Nino, which causes drought and dry weather, brings in its wake another phenomenon La Nina that causes high rainfall, almost as if nature was replenishing the loss. But unlike previous years, La Nina came almost immediately-within a few months-compared to the usual gap of 18-24 months. This meant that the heavy rains compounded the usual flooding in Bangladesh caused by the La Nina syndrome. The immediate cause therefore appears to be 'the exceedingly high rainfall in the upper catchment area in the Assam belt as well as within the country. This overwhelmed the loadbearing capacity of the three main river systems. The fact that the carrying capacity of the rivers had been declining for years also played a role. This was not only due to reasons such as tectonic movements but also poorly designed water flow management structures.

The earlier floods were more dramatic but less destructive because of their short duration The floods of 1998 showed that floods were not just destroying fields but infrastructures and income outlets as well. Ithad become both a rural and urban phenomenon. What mattered were not just the quanta of water flowing through but the duration Of the flood, which determined the level of damage.

Natural disasters in Bangladesh have their roots in the nature of its terrain, the physical geographic features, its long coastline and the tropical climate. The increasing density of population, by causing ecological damage, also adds to the misery. Bangladesh is a land of rivers and it has adjusted itself to a wet season when every year about 20 to 25 percent of its land area remains under water. During the period between 1870 and 1990, 12 major floods were reported within what are now the boundaries of Bangladesh. Prior to the floods in 2004, the worst floods in Bangladesh in the recent past occurred in 1998 and 1988.

Macro-economic losses due to floods in Bangladesh do indicate significant impacts on the aggregate output of the country. A comparison of the 2004 floods with the floods in 1988 and 1998 shows that the floods in 2004 have been less severe in terms of inundated area, duration, persons affected and loss of human lives. However, the 2004 floods have caused much greater damage to the economy in areas adjacent to the major rivers. Table 4 provides a comparison of the floods in 2004 with those of 1988 and 1998.

The analysis of the macroeconomic impact of floods in 2004 points out that the growth of per capita income is likely to fall from 4.5 percent to 3.7 percent due to income loss. The fall in per capita income may be more for the poor and the non-poor households that are very near the poverty threshold. An estimate of the non-poor household groups within 10 percent above the poverty line in the districts hit by floods in 2004 shows that they accounted for 4.3 million people in 2000. These people risk slipping into poverty unless they are protected under appropriate safety net programmes. In a country where the growth of aggregate output in the recent past has been around 5.5 percent, the magnitude of loss of output and assets due to natural disasters as observed during
the floods in 2004 does impact on the economy seriously. It may take two years just to get back to the pre-flood level of GDP, and this will have a consequent negative impact on the pace of poverty reduction.

The NWMP aims at institutional development, which proposes separation of planning and regulatory functions from implementation and operational functions at each level. One prominent step will be to progressively withdraw the central government agencies from activities that can be performed by local institutions and the private sector so that decentralization of decision-making takes place with stakeholders’ participation. For integrated water resource management, the Government will create an enabling environment through legal and regulatory reforms, research, reliable information flow and capacity building. Flood protection is given the topmost priority and it will be implemented for zila and upazila towns in phases using both structural and non-structural

Flood: Floods affect the poor most as they live in the agro-ecologically disadvantaged areas. The critical areas include char lands, coastal areas, haors and other deeply flooded areas. Flood shelter, flood forecasting and flood control measures are suggested as immediate intervention.

Major Sources of flooding in Bangladesh

• Tides and cyclonic rainfall

• Tides, cyclonic rainfall and surges, and overspill of Lower Meghna

• Local intense rainfall, eroded drainage, breaches in the Teesta and Brahmaputra

• Right Embankments and breaches in internal polder embankments and drainage

• congestion preceded by high flows in the major rivers

• Local intense rainfall, impeded drainages, spillage from the Brahmaputra and congested drainage on the Meghna

• Flash floods on transboundary rivers, local intense rainfall, impeded drainage and drainage congestion on the Meghna

• Flash floods on transboundary rivers local intense rainfall, impeded drainage and drainage congestion on the major rivers

• Flash floods and cyclonic rainfall

• High inflows through the Ganges and the Brahmaputra and surges

• Source: National Water Management Plan Project.

The following factors may also contribute to flooding:

• Excessive melting of snow in the Himalayas.

• Human interventions in all the major rivers in the form of building embankments, dams and
  barrages have shrunk the natural flood plain. They have also locally changed sedimentation
  pattern, causing rise of riverbed and higher flood water level.

• The sedimentation has been worsened by deforestation in Nepal and India. It causes more
  soil erosion and less surface retention of rain by the leaves of the trees and loose ground
  cover materials.

• Synchronisation of flood peak with high tide during full moon can make the flooding more
  damaging by raising the peak and prolonging the duration of the flood. Tidal heights vary
  between 60 cm and 3 m along the coastline.

• Change in the natural drainage pattern due to development activities. Both the intensity and
  the duration of flooding might have increased due to unplanned construction of roads and
  railway tracks. They have compartmentalised the countryside and disrupted the natural flow
  of water out of the flooded land.

Another serious problem in the urban areas is improperly planned land development, whereby low lying lands, canals, and ponds are filled up for constructing residential and commercial buildings. This is causing reduction in the floodwater retention areas, water logging and drainage problems. Construction of roads without appropriate environmental mitigation measures is also adding to these problems. Flood protection activities around urban areas without appropriate environmental mitigation measures are also responsible for water logging.

Due to rapid urbanization and unplanned and unregulated urban growth, lack of drainage and stagnation of rainwater affect many areas within large cities. The situation is particularly bad in Dhaka where many areas, both within old and new parts of the city, experience water logging. Unwise closure and encroachment of natural and artificial drainage and navigational canals have aggravated the situation. Many urban centres including Dhaka also suffer from annual as well as abnormal floods like the recent ones of 1987, 1988, 1998 and 2003. In major cities like Dhaka, the settlements of the poor are the worst affected by such floods and water logging.

Source: Bangladesh National Report
Progress of implementation of the Habitat Agenda (1996-2001)
Unlocking the Potential, National Strategy for Accelerated Poverty Reduction (PRSP)
Government of the People’s Republic of Bangladesh
Bangladesh Environment Facing the 21st Century:SEHD
Peoples Report 2002-2003: Unnayan Shamannay