Activities Related to Disaster Management for Earthquake In Bangladesh

Transcription

1 Activities Related to Disaster Management for Earthquake In Bangladesh I. ABSTRACT Ms. Suraiya Begum & Md. Shah Alam, Principal Scientific Officer, Bangladesh Space Research & Remote Sensing Organization (SPARRSO) & Prof. Dr. Mehedi Ahmed Ansari, Bangladesh University of Engineering & Technology (BUET) Earthquakes are related to faulting and tectonic instability of an area. Lying in the confluence of India Burme-Eurishya plate; Bangladesh is extremely prone to earthquake. A strong earthquake affecting the major cities like Dhaka, Sylhet, Chittagong, may result in severe damage and long term consequences for the entire country. Different organizations like Ministry of Disaster Management & Relief (MDMR), Disaster Management Bureau (DMB), National Center for Earthquake Eng.(NCEE), Bangladesh Meteorological Dept.(BMD),Bangladesh University of Eng. & Technology (BUET), University of Dhaka(DU), Chittagong University of Eng. & Technology etc. play a major role in earthquake risk mitigation to help the economic planning and Sustainable development of the country. In this paper, a brief summary of activities related to earthquake undertaken in Bangladesh have been presented. Key words: Awareness, Disaster Management, Hazards, Mitigation II. INTRODUCTION Bangladesh has an alluvial deltaic land with Himalayas on its north and Bay of Bengal on its south. It is located between N to N Lat and E to E Lon. It has an area of about 1, 47,570 sq,km with population more than 140 million. Most of its area is relatively flat lying in the deltaic plain of the Ganges-Brahmaputra- Meghna river system. Due to its geographic location and population density, it experiences diff. types of natural disasters which cause losses to lives and properties every year. Earthquake is the worst of them. The overall tectonics of Bangladesh and adjoining region is convective for frequent and recurring earthquakes. The geo-tectonic setting of the country is seismically very active. The adverse impact of all natural and man-made disasters needs to be reduced for sustainable development of the country. Consequently, it is needed to prepare against all possible disasters. III. EARTHUAKE ZONES OF BANGLADESH Bangladesh is divided into 3 earthquake zones : Zone 1: the less risky zone (includes Jessore, Khulna, Barisal and Noakhali Dist.) Zone 2 : medium vulnerable zone (includes Dhaka,Chittagong,Rajshahi, Dinajpur and Bogra Dist Zone 3 : the most vulnerable zone ( includes Sylhet,Mymensingh and Rangpur Districts. Fig-3 shows the zones.(source: Ansary,2005) IV. EARTHQUAKE AFFECTING IN BANGLADESH Bangladesh is a part of Bengal basin which is one of the most seismically active zone of Asian countries. It experienced some of worst earthquakes in the past which causes damage to cities of > RJSITM: Volume: 02, Number: 02, December-2012 Page 9

2 Sylhet, Chittagong Srimangal, Dhaka etc. Table-1 shows some remarkable earthquake affecting in and around Bangladesh and Fig-1 shows the hypocenters of them. (Source: internet) Table 1: Some remarkable Earthquakes affecting in Bangladesh Date Name( Place) Magnitude in Rihcter Epicenter distance from Dhaka (km) 14-Jul-1885 Bengal earthquake (Bogra ) Jul-1918 Srimangal Earthquake ( Srimangal) May-1997 Sylhet Earthquake (Sylhet ) Nov-1997 Chittagong Earthquake (Chittagong) Jul-1999 Moheskhali Earthquake (Cox;s Bazar ) Jul-2003 Chittagong Rangamati Earthquake Aug-2006 Fridpur Earthquake Aug-2007 Chandpur Earthquake Nov-2007 Bandarban Earthquake Sep-2008 Hajiganj Earthquake Mar-2008 ManikgonjEarthquake Sep-2010 HajiganjEarthquake Jun-2011 Faridpur Earthquake Aug-2011 ChandpurEarthquake Mar-2012 DoharEarthquake V. PARAMETERS OF EARTHQUAKE Generally, the tectonic movement of the earth s plates which forms the thin outer shell of the earth s crust causes earthquake. It is a geological hazard. There are mainly 4 measures for earthquake: (source: internet) Magnitude Intensity Epicenter Depth Magnitude measures the energy released which is generally based on the Richter scale measurements. Intensity measures the scale of damage or casualty of the disaster. VI. CATAGORY OF EARTHQUAKE According to the magnitude, the Earthquakes are normally categorized as: (Source: BMD) Very Minor (Less than 3 in Richter Scale ) Minor ( in Richter Scale ) Light ( in Richter Scale ) Moderate ( in Richter Scale ) Strong ( in Richter Scale ) Major ( in Richter Scale ) Great (8.00 or More in Richter scale ) > RJSITM: Volume: 02, Number: 02, December-2012 Page 10

3 VII. DISASTER MANAGEMENT GOB has undertaken a lot of plans and programs and formulated a set of mechanism for effective and systematic disaster management to mitigate the sufferings of disaster, for the sustainable development of the country. These are: Establishment of Ministry of Disaster management & Relief ( MDMR ),the Govt. coordinator which is responsible for all activities regarding all types of disasters. Establishment of disaster management organization named Disaster Management Bureau (DMB) Establishment of Council & Committee upto union level to maintain proper coordination among the concerned departments and and community people and to ensure their proper functioning. Establishment of Emergency Operation Center for collect information about the disaster during the emergency period. Establishment of Task Force to operate awareness programs. For the mechanisms to be best operative, the Standing Orders on Disaster (SOD) act as a guidebook. (Country Report: DMB). Besides these, SPARRSO, Bangladesh has taken some projects for strengthening capability of disaster monitoring systems for better disaster management towards sustainable development. VIII. ORGANIZATION RELATED TO EARTHQUAKE MANAGEMENT Disaster mitigation and management is not the responsibility of govt. alone or any specific organization or agency. It requires skilled human resources and well-coordinated efforts from all concerned bodies as well as the public. These are: Ministry of Disaster Management & Relief (MDMR) Disaster Management Bureau (DMB) Bangladesh Meteorological Dept. (BMD) Bangladesh Earthquake Society (BES) Directorate of Relief and Rehabilitation (DRR) Red Crescent Society (RCS) Bangladesh Space Research & Remote Sensing Organization (SPARRSO) Water Development Board (WDB) Geological Survey of Bangladesh (GSB ) Bangladesh University of Engineering & Technology (BUET ) Dept. of Geology of Dhaka University Public Works Dept. (PWD) Armed Forces Div.(AFD) NGO's etc. IX. EARTHQUAKE MANAGEMENT/MITIGATION The casualty and damage due to an earthquake can be reduced by suitable mitigation, measures which are categorized as: 1) Structural 2) Non-structural In order to reduce the consequences of major earthquake in the city of Bangladesh, it is necessary to give equal importance to both Structural and Non-Structural mitigation measures. > RJSITM: Volume: 02, Number: 02, December-2012 Page 11

4 IX.B. Structural mitigation Structural measures are those that directly influence the building stock through strengthening of code provisions and the prevalent constructions practice. As part of structural measures GOB has So far constructed shelters nearby the highly vulnerable areas. Set up a committee in 1992 to prepare Building Code setting the minimum standard which had to be met to construct any building. Public Works Department (PWD) arranged several in-house workshops to train their engineers about earthquake, to use the seismic codes in designing buildings. Dept. of Geology of Dhaka University has started the vulnerability assessment of their existing buildings to prioritize their retrofitting measures. IX.C. Non-Structural mitigation The non-structural mitigation measures include improvement in the state of awareness, preparedness, and other activities before and after disaster. IX.C.1. Awareness / Preparedness Preparedness/awareness requires monitoring, workshop/seminars as well as community based management. Monitoring Though Earthquake is rather difficult to predict, Bangladesh Meteorological Dept (BMD) has installed the Digital Seismic Equipment for earthquake monitoring which has 4 components: Broadband seismometer at 4 stations (Dhaka, Chittagong, Rangpur and Sylhet Districts ) Borehole Seismometer at 2 stations upto a depth of 100m( Dhaka and Rangpur Districts ) Short Period Seismometer at 2 stations ( Chittagong and Sylhet Districs ) Strong motion Accelerometer at 4 stations (Dhaka, Chittagong, Sylhet and Rangpur dist.) Fig-2 shows their locations. The data obtained from these seismometers and accelerometers are being processed and analyzed to find out the following parameters of the earthquake: Location ( Lat/Lon ) Magnitude ( Richter Scale) Origin Time Focal Depth These observed data /massage are sent to New Delhi Regional Telecom Hub (RTH) and to the local concerned offices, by Global Telecommunication System (GTS ). BMD share these data with BUET, DU, GSB, PMO via radio modem. Besides this, Bangladesh has the following earthquake monitoring systems: Geohazard research group of Dept. Geology of Dhaka University in cooperation with USA, installed a broadband seismometer in Dhaka and several GPS devices at some places of Bangladesh for earthquake monitoring. > RJSITM: Volume: 02, Number: 02, December-2012 Page 12

5 Bangladesh University of Engineering & Technology (BUET ) installed seven free-field seismic instruments on Jamuna Bridge and on its surrounding areas ( east and west end of the bridge, at Dhaka, Gazipur,Bogra and Nator Dist.(Fig-5). In addition, they installed a borehole accelerograph at 57m. depth. BUET also acquired 60 analog SMA-1 type Accelerograph (Fig-6) installed at different Govt. institutions of the country to acquire earthquake data to develop the attenuation laws for Bangladesh, which can be readily used for earthquake hazard analysis and updating of seismic zonation map. Workshop/Seminar/project Disaster Management Bureau (DMB) with the help of different international funding agencies and local administration and other organizations like Bangladesh University of Engineering & Technology (BUET), Bangladesh Earthquake Society (BES), Bangladesh Academy of Sciences (BAS), Dhaka University (DU), Bangladesh Meteorological Dept. (BMD), Chittagong University of Engineering & Technology (CUET), Bangladesh Red Crescent Society (BDRCS), Local Govt. Engineering dept (LGED), BRAC University, Institute of Engineers Bangladesh (IEB), Institute of Diploma Engineers Bangladesh (IDEB), Real Estate Housing Association of Bangladesh (REHAB), SPARRSO,CARE Bangladesh etc. organized and conducted diff. types of workshop, seminar, symposium and other public awareness and earthquake preparedness programs throughout the country. Community based management Govt. alone cannot properly manage and handle all types of disasters. It requires active participation of local people to provide necessary service during and after the disaster. This new approach of managing disaster known as Community-Based -Approach (CBA), is going on and popularized gradually. BUET has undertaken several projects related to earthquake vulnerability assessment and community awareness. They also started earthquake safety ( mock drill) training to diff. school students (Fig-7). Disaster Management Bureau (DMB) also has published a Disaster Management Training Manual for public awareness guidelines. IX.C.2 Other activities/policies Mapping /Survey Geological Survey of Bangladesh (GSB) is involved with survey and the development of seismic zonation maps for pre and post disaster management. Dept. of Civil Engineering of BUET and SUST undertaken field survey in diff. cities and collected the infrastructure information of diff. existing buildings. For future seismic events and mitigation, BUET and Shah Jalal University of Science & Technology (SUST) prepared microzonation maps of major cities to know local site conditions Fig-8 shows microzonation map of Dhaka. CARE Bangladesh has developed a seismic risk scenario for diff. cities.. Research /Institutional Activities Dept. of Geology of Dhaka University has got funding from Ministry of science and Technology to carryout researches in the field of earthquake hazard assessment. BUET has also undertaken diff. types of research activities related to earthquake. > RJSITM: Volume: 02, Number: 02, December-2012 Page 13

6 Department of Civil Engineering of BUET has established a National Center for Earthquake Engineering (NCEE) and offers Postgraduate courses on earthquake Engineering, Soil Dynamics, Structural Dynamics and Vibration Analysis. Directorate of continuing education, BUET, Institute of Engineers Bangladesh (IEB) has conducted short courses on Earthquake resistant design and Retrofitting of building Institute of Diploma Engineers Bangladesh (IDEB) has offered several courses on earthquake vulnerability and seismic design of structures. Relief /Rehabilitation The damage/losses due to any disaster as well as earthquake is assessed by Disaster Management Bureau (DMB ) and Ministry of Disaster Management & Relief (MDMR ). They are responsible operate relief activities and medical assistance for the victim people with the help of concerned agencies. Armed Forces Div.(AFD) also activate Disaster Management and Relief Monitoring Cell in Prime Minister s Office and monitor rescue operation after any disaster. XI. Conclusion Bangladesh is one of the disaster (earthquake) prone country with extremely limited resources. The development of the country is not possible without the integration of disaster management which is dependent upon awareness and early warning. Pre-disaster planning is much more useful than a post disaster management. All Societies at risk of natural disasters require greater awareness of the threats they face and need appropriate education and training to mitigate the hazards. Realizing these facts, Bangladesh is striving hard to establish an elaborate and systematic disaster management system. For this reason, we need to have a system and facility of advanced technology for Early Warning and Monitoring earthquake. International cooperation and mutual collaboration is necessary for that. Ref: 1) Internet source 2) Bangladesh Meteorology Dept. Data 3) Disaster Management in Bangladesh(country report-2003) 4) World Environment Day(disaster prevention: earthquake) 5) Periodic Briefing session on Earthquake Disaster Management(DMB) > RJSITM: Volume: 02, Number: 02, December-2012 Page 14

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