Dr. Foqan Uddin Ahmed :
In the global context, earthquake stands as the number one natural disaster in terms of damage, destruction and loss of lives and properties. It is the most “deadly and unpredictable natural event”. About 60% of the world casualties associated with natural disaster are caused by earthquake. On average, world experience about one million earthquakes a year, among which 20 are sufficiently violent to destroy a habitable area. Besides, average global record indicates that 1 very large event (M>8) 10 medium (m>7) and 100 moderate earthquakes occur year.
Earthquake is a naturally induced phenomena created as a result of sudden movement of rocks along the existing fracture/fault under the surface of the earth. This movement occurs when the rocks can no longer withstand the tensions and forces that have built up in them. When the rocks can not bend any more, they suddenly fracture and rebound that relieve the pressure where the earthquake first begins is called focus and the point on the surface of the earth directly above the focus is known as ‘epicenter’. One easily understands the mightiness and its strength when an earthquake occurs in a given area. For example and earthquake with M 7 releases 30 times more energy than that of an earthquake with M 6, while it releases 300 times more energy than that of an earthquake with M 5. The modified Mercalli Scale measures the extent of damage of an earthquake in an affected area, while magnitude is the release of energy during an earthquake devised by C.F Ricter in 1935.
Considering the above scenario we must prepare ourselves to survive and steps must be taken to understand and quantity the earthquake problem, build structures capable of resisting earthquake forces and develop early warning, monitoring as well as post disaster mitigation system. In fact, preparedness has been defined by N.W Carter as measures which enable governments, organizations, communities and individuals to respond rapidly and effectively to disaster situations. Preparedness measures include the formulation of viable disaster plans, the maintenance of resources and the training of personnel.
The occurrence of earthquakes is part of the natural process in the earth is geophysical system. Under the present stage of scientific development it is not possible to stop such natural events, and even if it was possible to do so, we should not intervene such internal system of the earth.
However, understanding the characteristics of internal geo-physical process of the earth and possibility of its forecasting as well as preparedness can reduce the casualties from such incident considerably.
However, locating the epicenters and monitoring characteristics of each shock may improve our understanding considerably and lead us to develop some preventive measure to live with earthquake. In the global context standard earthquake preparedness include the major aspects are like- natural Disaster Policy focusing on earthquake, provide Training and Public Awareness related to earthquake risk, integrate Seismic resistance into the process of new construction, improve emergency response planning and capability, develop safety system of all public buildings, Improve seismic performance of existing buildings and introduce community-based per and post earthquake management.
Bangladesh has tremendously improved its management and mitigation measures of natural disasters, like cyclone and flood, but the mitigation strategies regarding earthquake has remained nearly in its infant stage. Bangladesh should take certain measures to mitigate the suffering from earthquake incident. At the beginning of earthquake mitigation and management issues can be incorporated within the existing disaster management program of the government, ranging from National Disaster Management Council to Union Disaster Management Committee. Moreover, procurement of instruments required for rescue operations must get top priority in the management agenda. Proper training to be arranged for community level, voluntary organizations and NGOs to motivate and increasing of people’s awareness can reduce the casualties from any earthquake incident considerably.
It is thus immediate necessity to upgrade and improve the existing earthquake measurement station at Ambagan in Chittagong and complete the two other proposed stations at Dinajpur and Sylhet.
Construction of new buildings should strictly follow the national buildings codes 1993 particularly enforcement of laws and orders and development of people awareness has no alternatives. Earthquake vulnerability of any place largely depends on its geology and topography, population density, building density and quality, and finally the coping strategy of its people and it shows clear spatial variations. It is thus necessary to identify the scale of such variations and take necessary measurements to cope with that.
An earthquake atlas is the presentation of facts relating to earthquakes and the guideline for earthquake mitigation measurements at regional scale in the form of map, graphics picture and text. Such an atlas provides clear guidelines to post disaster rescue operation, regional scale mitigation strategies and stepwise disaster management activities.
We do not have any such atlas neither at national level nor a regional level. However, it is the timely demand to prepare and earthquake vulnerability assessment atlas of Bangladesh in general and for the major cities in particular. Large scale mitigation measurement needs huge initial investment however, to serve human lives and properties, we should not hesitate to do so.
Developments of awareness program educate people regarding the causes and consequences of earthquakes. And also to disseminate knowledge to them regarding their responsibilities before, during and after the earthquake through seminar, symposium and workshop and also through non-formal education by Go and NGOs.
The above discussion clearly indicates that governments’ concerned organization alone is not enough to prepare countrywide population in this regards.
Communities and individuals must involve discharging the responsibilities and to observe the formalities in connection of facing this challenges as well as respond rapidly and effectively to disaster situations. Unless these measures are taken seriously and given adequate priority the preparedness in a country like Bangladesh to face the earthquake would remain far from reality.
