Bangladesh is prone to a variety of natural hazards. It has witnessed the havoc of some of the worst natural disasters of the world due to tropical cyclones and storm surges. Floods and local seasonal storms are annual events which cause loss of lives and damage to housing, agriculture and economy. The country is also exposed to the risk of earthquakes. There are other natural hazard concerns such as coastal erosion and sea level rise due to global warming, which have been in the limelight in recent years. Bangladesh is exposed to threat of hazards resulting from a number of natural disasters and remains classified as one the most vulnerable countries. Majority of the country is affected by cyclone, drought and floods. Bangladesh is prone to the natural disaster of flooding due to being situated on the Ganges Delta and the many tributaries flowing into the Bay of Bengal. The coastal flooding twinned with the bursting of Bangladesh's river banks is common and severely affects the landscape and Bangladeshi society. 75% of Bangladesh is less than 10m above sea level and 80% is flood plain, therefore rendering Bangladesh a nation very much at risk of further widespread damage despite its development. Whilst more permanent defenses, strengthened with reinforced concrete, are being built, many embankments are composed purely of soil and turf and made by local farmers. Flooding normally occurs during the monsoon season from June to September during the monsoon. The convectional rainfall of the monsoon is added to by relief rainfall caused by the Himalayas. Melt-water from the Himalayas is also a significant input and flood every year.
Many natural hazards were seen in Bangladesh at recent times which destroyed the regular life as well as causes extensive damages to the life and property. Common Hazards of Bangladesh are:
4. Land sliding
Fig: Hazard Scenario in Bangladesh
In recent years the frequency of abnormal floods in Bangladesh has increased substantially, causing serious damage to lives and property. Floods are the most significant natural hazard in the country causing extensive damage to human life and property. The country lies on the downstream part of three major river basins: Brahmaputra, Ganges and Meghna and thus is frequently flooded. There have been many destructive floods in Bangladesh, including very severe floods of 1987, 1988 and 1998. The 1988 flood set a new record for flooded area, while 1998 flood was unprecedented with its long duration. The flood damage potential in Bangladesh is increasing due to the possible causes of climate change, urban concentration in the three river basins, encroaching of settlements into flood prone areas, and overreliance on the safety provided by flood control works such as levees, reservoirs. There are two types of floods which occur in Bangladesh: annual floods (barsha) that inundate up to 20% of the land area; and low frequency floods of high magnitude that inundate more than 35% of the area (bonna). The major floods that occurred in 1954, 1955, 1974, 1984, 1987, 1988, 1993, 1998, 1999, 2000 and 2007 have been very destructive and caused serious threat to lives and economy. In the context of human exposure in flood hazard zones, nearly 19,279,960 people are present in these zones and Bangladesh ranks 1st among 162 nations. Similarly, the modeled amount of GDP in seismically hazardous zones puts Bangladesh 3rd among 162 countries.
Table 1: Major Floods in Bangladesh
Impact of Flood
* Economic loss
* The government is asking for "any form of assistance" from any government or agency. It estimates the damage so far at $140 million. Nearly 500,000 tonnes of rice has been ruined in the fields. More than 2,000,000 acres of agricultural land have been submerged...