Have We Been Shaken Up Enough?
In the wake of recent earthquakes in the country, DR. A. S. M. MAKSUD KAMAL surveys the level of preparedness and what remains to be done.
Half of the world population already lives in the urban area with the highest urban growth rates in the developing world. By 2050, the urban population of the developing world will be 5.3 billion; Asia alone will host 63 percent of the urban population, or 3.3 billion people. With an urban growth rate of more than 4 percent annually, Dhaka, which already hosts more than 13 million people, is one of the fastest but unplanned growing cities in Southern Asia, and is projected to accommodate more than 20 million by 2025.
Recent earthquakes in India (Bhuj, 2001), Pakistan (2005), China (Sichuan, 2008) and Haiti (2010) imply that earthquake disasters are mostly human-induced due to poor constructions because of unavailability or noncompliance of building code and unplanned urbanisation practices. Moreover, earthquake impact on Gross Domestic Product (GDP) implies that poor nations suffer more than rich nations. For instance, earthquakes of the same magnitude cost the nation's economy in Haiti at least 15 percent of its GDP but less than 1 percent in China. Factors which multiply the earthquake vulnerability of the major cities (Dhaka, Chittagong and Sylhet) of Bangladesh include phenomenal growth of the building stocks after independence, poor construction practices flouting existing building codes, a good number of buildings constructed before introduction of the code in 1993, rapid urbanisation on unsuitable land, high population density and narrow road networks in the cities, poor capacities of the major responding organisations during the period of emergency and little awareness (of what to do) among city dwellers.
Bangladesh can be regarded as a supermarket for natural disasters. Flood, cyclone, storm-surges, river erosion, landslides, drought, earthquake and climate-induced hazards can be noted in this context. Though in the last one hundred years, the country has not been jolted by devastating earthquakes, in the last couple of years, the country experienced very minor to moderately low seismic disturbances more than 130 times. It should be noted that between 2000-2010, earthquakes with magnitude over 4.0 within Bangladesh territory rocked the country eight times. Historical evidence reveals that in the last 250 years, eight big earthquakes occurred with magnitude >7.0 in and around Bangladesh. The Great Indian earthquake of June 12, 1897 (magnitude 8.3-8.7), whose epicentre was about 230 kilometres away from Dhaka, caused extensive damage in Bangladesh, killing almost 450 people mostly in the north-eastern part of the country. Being located in the seismotectonic command areas of the Himalayan mountainous terrain, the countries stretching across this mountainous belt are a hotbed of seismic activity due to the existence of geological plate boundaries and the corresponding development of active fault zones in the region. It is postulated that around 50 million people are at risk of encountering Himalayan quakes in this area, many of them residing in densely populated cities in Bangladesh, Bhutan, India, Nepal and Pakistan.
Considering the potential threat of the earthquake hazards, Disaster Management and Relief Division of the Ministry of Food and Disaster Management has undertaken systematic approaches in reducing the earthquake vulnerability of the country through Comprehensive Disaster Management Programme (CDMP) since 2007. Besides CDMP, other wings of the Government such as Disaster Management Bureau (DMB), City Development Authorities (RAJUK), Public Works Department (PWD), Fire Service and Civil Defence (FSCD), Armed Force Division (AFD) and City Corporations are also working on addressing and reducing the earthquake risk of the country. NGO initiatives should also be noted in this context. CDMP-I initiatives considered the following procedures taking onboard the respective organisations for earthquake preparedness and risk reduction: hazard, vulnerability and risk assessment of Dhaka, Chittagong and Sylhet following microzonation techniques, development of risk-based spatial contingency plan for national, city and relevant agency levels, capacity build-up of the major organisations for conducting search and rescue operations and promoting scientific research as well as raising awareness of the city dwellers and decision makers.
Figure 1: Plate boundary and historical earthquake epicentre
Earthquake Hazard, Vulnerability and Risk Assessment of the major cities
Earthquake is a sudden movement of the earth's crust caused by the release of stress accumulated along geological plate boundary, fault zones or by volcanic activities.
In the immediate outside of the eastern frontier of Bangladesh, Eurasian and Indian Plate boundaries exist (Fig: 1) while in the Assam region of the northeastern territory of the country, the convergence of three plates, viz, Indian, Eurasian and Burmese subplates are located and known as Assam Syntaxis, where Great Assam earthquake occurred in 1950 (M 8.6). Beside these plate boundaries, three major active faults, viz, Madhupur Fault (MF), Dauki Fault (DF) and Eastern Plate Boundary Fault (PBF), located inside the country (Fig: 2) have caused historically damaging earthquakes (magnitude over 7.0) in the region, of which, epicentres of two earthquakes (Srimongal Earthquake of 1918 along middle part of Plate boundary fault and Bengal Earthquake of 1885 along Madhupur blind fault) originated within the country.
For the first time, geological fault lines are being studied in Bangladesh, employing national and international experts and following global standard procedures. Studies reveal that recurrence periods of the fault lines located in the northern and central parts of the country are around 230-350 years, having the potential to generate 7.0-8.0 magnitude earthquakes, while fault lines located in the eastern part of the country calculated around 900 years have the potential to generate > 8.0 magnitude earthquake. Earthquakes occurring even outside the territory of Bangladesh may cause significant damage in the country because of its thick soft-sedimentary cover over the engineering bed-rock (relatively hard and compacted rock).
Earthquake hazard assessment has been conducted for Dhaka, Sylhet and Chittagong city areas to determine ground motion, soil liquefaction and slope failure.
-Ground motion hazard is determined comparing the value of 'g' (980 cm/sec2) to represent the severity of earthquake damages.
-Earthquake hazard sizes can be represented in two terms, magnitude and intensity respectively.
-Magnitude represents the amount of energy released during an earthquake, which is computed from the amplitude of the seismic waves. A magnitude of 7.0 on the Richter scale indicates an extremely strong earthquake. Each whole number on the scale represents an increase of about 32 times more energy released than the previous whole number represents. Therefore, an earthquake measuring 6.0 is about 32 times more powerful than one measuring 5.0.
-Intensity is subjective, depending on observations of damaged structures, presence of secondary effects and the degree to which the quake was felt by individuals. There are 12 levels of intensity indicated by Roman number as per Modifided Mercalli Intensity Scale. For instance, intensity 'VIII' represents collapse of poorly constructed buildings and damages to well built structures, while intensity 'X' represents collapse of even well-built structures. Calculated strong ground motions reflect that Dhaka and Sylhet are susceptible to experiencing intensity VIII, while Chittagong could experience intensity around X. Intensity seems too high for Chittagong because of the proximity of the fault zone and its potential of earthquakes of magnitude around >8.0.
-Soil liquefaction is the hazard phenomena which reflects loss of bearing capacity of the soil due to ground shaking. Soil behaves like liquid due to which buildings topple down. For instance, in Chittagong, two to three areas are susceptible due to soil liquefaction, while this figure is less than half for Dhaka and Sylhet.
Building and Lifelines Inventory, Vulnerability and Risk Assessment
Vulnerability is the degree to which a person, system or unit is likely to experience damage due to exposure to hazard. It is estimated that there are 326,000, 182,000, and 52,000 buildings in Dhaka, Chittagong, and Sylhet City Corporation (Fig. 3) areas respectively. Afterwards, building stocks were differentiated into structural types. Such as, in the Dhaka City Corporation area, different types of reinforced concrete and masonry buildings are counted at 85,000 and 180,000 respectively.
To assess the vulnerability of the buildings, three level surveys were conducted in this study, taking into consideration the number of stories, occupancy class, structural type, number of occupants during the day and the night, age of the building, etc. (Level-1); dimensions of columns, concrete and masonry walls (Level-2); and dynamic measurement on few selected buildings in three cities (Level-3).
Using the same methodology for lifeline inventory, essential facility inventory was developed. For instance, the lifeline inventory in the Dhaka City Corporation area includes over 1,270 kilometres of highway road, 10 highway bridges, and pipeline lengths for potable water, waste water and natural gas of 1,100, 630 and 830 kilometres respectively. The essential facility inventories through CDMP study consist of medical care facilities, i.e. hospitals and medical clinics, emergency response facilities, i.e. police stations, fire stations and emergency operation centres and schools. There are 600 hospitals, 2,700 schools, 10 fire stations, 62 police stations and 18 emergency response agency offices in the Dhaka City Corporation area; while in Chittagong, there are 162 hospitals, 1,033 schools, 12 fire stations, 11 police stations and 11 emergency response agency offices; and in Sylhet, there are 87 hospitals, 211 schools, two fire stations, six police stations, and nine emergency response agency offices.
Based on the vulnerability factors of the building stocks and lifelines, vulnerability maps were developed which show the characteristics of the buildings, essential facilities, and lifelines that make them susceptible to the damaging effects of earthquakes. For instance, the most common vulnerability factor in Dhaka city is soft story (ground floor of the building is open for car parking) and overhanging (extension of existing structures over the ground floor).
Figure 2: Major geological fault lines of the country
Risk is the conditional probability and magnitude of damage that occurs on the exposures to a hazard event. Risk assessment reveals that if an earthquake occurred at Madhupur fault with magnitude 7.5, about 72,000 buildings will be damaged in Dhaka beyond repair. The building related economic losses for this earthquake are estimated at more than 6,000 million USD. It is estimated that about 140,000 buildings will be damaged if a 8.5 magnitude earthquake is generated from the plate boundary fault located near Chittagong. During an earthquake of 8.0 magnitude from Dauki fault, about 25,000 buildings will be damaged beyond repair in Sylhet. There will be severe damage to essential facilities like hospitals, schools and police stations. For instance, Madhupur fault earthquake will cause moderate to complete damage in Dhaka to about 250 hospitals or clinics, 1,300 schools as well as 30 police and four fire service stations. In Dhaka, there are about 60,000 hospital beds available for use. On the day after the earthquake, it is estimated that only 24,200 hospital beds (40 percent) will be available for use by patients already in the hospital and those injured by the earthquake. After one week, 54 percent of the beds will be back in service. By the thirtieth day, 70 percent will be operational. During this period there will be around 80 leaks and 270 breaks in the water supply system, 100 leaks and 350 breaks in the waste water system and 60 leaks and 200 breaks in the gas supply network. It has been observed that about 50 percent of highway road, 70 percent of railway track and six major highway bridges in Dhaka are located in moderate to very high liquefaction susceptibility areas. Moreover, about 55 percent potable water pipeline, 52 percent waste water treatment pipeline, 56 percent gas pipeline in Dhaka are located on moderate to very high liquefaction potential area.
Such microzonation-based damage assessment is a common practice over the globe for developing preparedness and emergency response plan/contingency plan for the national and major responding organisation though it cannot pinpoint damage to individual buildings.
Development of Scenario-based Earthquake Contingency Plan
Usually many agencies are involved in accomplishing the activities for preparedness, response and early recovery to reduce the risk of any big disastrous event. Experiences have shown that all agencies need to work together under a well-designed and fully-coordinated plan for optimum and efficient preparedness, response and early recovery, usually known as Contingency Plan, in a systematic manner so that their capacities and resources are best utilised to fulfil the need by complementing and supplementing other agencies. From CDMP-I initiatives, scenario-based contingency plans have been developed for national level, three city corporations (Dhaka, Chittagong and Sylhet) and five key Responder Agencies viz., Armed Forces Division (AFD), Fire Service & Civil Defense (FSCD), Directorate General of Health Services (DGHS), Disaster Management Bureau (DMB) and Directorate of Relief and Rehabilitation (DRR). Moreover, lifelines and utilities agencies, such as Power Distribution Company Limited, Dhaka Water Supply and Sewerage Authority, Titas Gas Transmission and Distribution Company Limited, Bangladesh Telecommunication Company Limited (BTCL) and humanitarian assistance providers have also been addressed in the contingency planning process. This Plan adopts scenario-based Contingency Planning approaches that involve the development of specific scenarios through the hazard, vulnerability mapping and risk estimation assessment, which are then used as a basis for developing an emergency response plan with regard to earthquake hazard based on the need assessment of the organisation.
Realising the need for coordinated and comprehensive emergency response, the United Nations has been promoting its humanitarian response activities in a cluster approach. This approach has proved to be effective and efficient in responding to recent disasters, for instance, during the October 8, 2005 Kashmir earthquake in Pakistan. Hence, it has been assumed that this concept of response operations in functional clusters be applied in Bangladesh also in case of possible earthquake disaster. In this approach, under National Earthquake Contingency Plan, all response activities are grouped into nine relevant operational functional clusters based on the similarity of work, normal time and disaster time mandates of different relevant organisations and possible complementarity in the resources and capacities. Beside emergency opeartions, preparedness and early recovery actvities are also assigned for each functional cluster to reduce the earthquake vulnerability to a certain manageable level. The proposed operational functional clusters with lead and support agencies under National Earthqauke Contingency Plans are: Emergency Operations Cluster 1 Overall Command and Coordination (lead-DMB), Emergency Operations Cluster 2 Search, Rescue and Evacuation (lead-FSCD), Health Cluster (DGHS), Relief Services (Food, Nutrition and other Relief) Cluster (lead-DRR), Shelter (Including Camp Management) Cluster (lead-DMB), Water Supply, Sanitation and Hygiene Cluster (lead-Local Government Bodies: City Corporations/pourashava), Restoration of Urban Services Cluster (lead-Local Government Bodies: City Corporations/pourashava, Transport (Road, Rail, Air, Sea) Cluster (lead-BRTA, BIWTA, Bridge Authority, Security and Welfare Cluster (lead-Police). The role of Armed Force Division is actively associated with almost all the clusters.
With regard to each functional cluster, spatial planning requirements in terms of locating facilities at appropriate locations, need assessment based on spatial coverage, identifying alternative locations and routes for emergency supplies, identifying emergency evacuation routes and places for temporary shelters and medical facilities, pre-positioning of facilities, etc., have been identified and mapped under GIS environment that would enable the key emergency responders to act in a coordinated as well as cohesive way. For instance, the total number of displaced population needing temporary shelter has been estimated at around 870,000 within Dhaka city during Madhupur earthquake. It is estimated that 50 percent of the displaced people will need immediate shelter after the earthquake and the remaining 50 percent will manage shelter at their relatives' and other places.
The population evacuated in immediate shelter requires about 3,800 cubic meters of emergency water at a rate of 15 litres per capita per day. The population taken outside require about 9,200 cubic meters of water per day. So, the total emergency water needed in the emergency shelters is about 13,000 cubic metres per day. Pre-positioning of this amount of water at the planned spaces before the earthquake is the most appropriate way to provide immediate emergency response of water. To manage toilets in the immediate shelters, space is the main challenge related to sanitation. There should be one toilet for every 20 people in the emergency shelter, coming to about 13,000 toilets needed in the open spaces within Dhaka City and an additional 30,000 toilets need to plan for the people of Dhaka who need immediate shelter outside Dhaka city.
The total number of skilled/trained workers required for repairing the potable water and waste water system within Dhaka City Corporation area after an earthquake is about 1,800 people per day to repair the system within seven days, 900 in 14 days and 420 in 30 days. The total estimated cost required for repairs is about 27 million USD.
The contingency plans have been developed in around 30 interactive meetings with the agencies. Moreover, two workshops have been conducted in national level to validate the plans. The plan is a measure of the quality of the process. A good planning process will produce a adequate plan. Even though the earthquake that occurs may be very different from the one planned for, the plan will still be useful. A good contingency plan ensures better preparedness for any emergency that may occur, even one that is very different from the scenario in the plan. Legal provisions and organisational set up, functional response roles and responsibilities assigned for the agency, operating procedures guideline and readiness checklists are also outlined in this plan.
Microzoning led risk assessment and corresponding development of contingency plan is a new approach in Bangladesh through CDMP initiatives. There is still room to improve the earthquake hazard assessment. Once the hazard scenarios change, vulnerability and risk will also bring updated results. In order to understand and operate the plan, training on incident command system and restoration of lifelines within shortest possible time have been provided to the professionals of the responding organisations. To cope with emergency situations, organisations need to exercise the plan through simulation drills.
Recent initiatives for capacity building for Search and Rescue operations and Earthquake research activities
Strengthening with Search and Rescue equipment: Disaster Management Bureau procured heavy equipments worth around BDT 70 crore to enhance current facilities of search and rescue operations of Armed Force Division (AFD), Fire Service and Civil Defence (FSCD) and City Corporations. Moreover, FSCD professionals have received advanced training on Medical First Responder (MFR), Collapsed Structure Search and Rescue (CSSR) and advanced training on civil defence through the initiatives of CDMP and other organisations at home and abroad. The government is also keen to identify effective equipment and procure them through the guidance of recently formed Earthquake Preparedness and Awareness Committee, headed by the minister, Ministry of Food and Disaster Management (MoFDM).
Development of urban community volunteers, a unique initiative of CDMP for community involvement in search and rescue operations to support regular forces of the government: Global scenarios reflect that during any disaster, community people are the first responders. Considering the model of Cyclone Preparedness Programme (CPP) of the Government of Bangladesh and Red Crescent Society, CDMP-I has taken initiatives to develop urban community volunteers through FSCD. CDMP initiatives had been followed by some NGOs such as, Islamic Relief and Action Aid, extending their support to FSCD for developing volunteers. So far, more than 1,000 volunteers have been developed in Dhaka, Chittagong and Sylhet, who have been trained on search, rescue and first aid to support the regular forces of the government during the period of emergency. Two hundred volunteers in each ward of the city corporations will be trained and, by the next five years, around 62,000 urban volunteers will be developed throughout the country.
Capacities to conduct scientific research are not yet adequate in the country. CDMP has procured scientific equipment for GoB organisations as well as academic institutions to promote application-oriented earthquake research activities in the country. Through the procurement of these equipments, the country is now equipped to some degree for engineering and scientific solutions related to strong ground motions.
The country is already equipped with 16 seismometers, 12 controlled by the geology department of Dhaka University and four by the Bangladesh Department of Meteorology (BMD). Collaborative research programmes with foreign universities are also available in Bangladesh University of Engineering and Technology (BUET), Chittagong University of Engineering and Technology (CUET) and Dhaka University.
Professionalizing Disaster Management: CDMP has been working with National Curriculum and Text Board (NCTB) to incorporate earthquake preparedness and evacuation drill into elementary to secondary level text books as well as supplementary learning materials. Disaster management courses have been introduced in public training institutes and a number of public and private universities (University of Dhaka, BRAC) of the country to a level through CDMP initiatives. Earthquake risk management is also taught in these courses and degree programmes. Moreover, CDMP has been supporting the development of earthquake engineering curriculum at CUET and Sylhet Shahajalal University of Science and Technology (SUST).
Safety and evacuation drill in schools: Due to irregular shape and poor constructions, schools are most vulnerable to earthquakes. The Pakistan Earthquake of 2005 killed around 17,000 school children and teachers in a total death toll of 75,000. The Sichuan earthquake in China with a total death toll of 85,000 killed around 10,000 children and teachers. In all earthquake-prone countries, school safety and evacuation drills are conducted regularly and have saved thousands of lives.
It has been observed that even in the most severe earthquakes, buildings rarely collapse completely. Injury and even death is most often caused by the shattering and falling of non-structural elements, such as window glass, ceiling plaster, lighting fixtures, chimneys, roof tiles and signs. There will be no time to think about what to do; therefore, of all earthquake-preparedness measures, earthquake drills are the most important. There is a need to educate the school children and teachers on safety and evacuation measures/drills to make the schools safer, and to know what to do before and after an earthquake occurs in their area. The earthquake safety lessons they learn will stay with them and be useful in adulthood, both for themselves and their children. In CDMP-I, school safety and evacuations drill has been conducted in 28 schools in Dhaka, Chittagong and Sylhet on a pilot basis, along with some NGOs which have done so.
A standard school earthquake safety guidebook and posters have been prepared and distributed to the schools. It is planned to extend this drill in a more effective manner to 65 schools in the earthquake risk-prone cities of the country in CDMP-II. In order to make safety and evacuation drills sustainable, equipments to conduct the drills will be provided to the schools and they will be organised with the administrative framework of the primary and secondary school directorate.
Training for religious leaders (imams) for awareness about earthquake dangers: Natural disasters have usually had some religious meaning for people in ancient times. But, this kind of religious interpretation of natural disasters has declined gradually because of the influence of education in society. Religious leaders have the access to motivate and educate the people in reducing the vulnerability of different disasters. Keeping this in mind, religious leaders were educated through this activity on the earthquake dangers and what to do to reduce the non-structural vulnerability at the household level. The religious leaders were given preliminary knowledge on the earthquake hazard and training on the vulnerability of the non-structural elements and asked to disseminate this during 'khutba' of Friday prayers.
Training for masons and bar-binders for safe construction practices: Construction of residential buildings in a developing country like Bangladesh is primarily carried out by the informal sector, mostly the owners/builders. The workforce (masons, bar-binders and plumbers) employed in this sector do not have any formal training. Most of them acquire skill either through trial and error or through practical experience. While there have been initiatives by the respective government organisations, such as RAJUK, towards improving seismic performance of new constructions by incorporation of seismic designs in the building construction process, it can still be anticipated that local masons and small contractors will continue to play a significant role in the building construction process. So, any enhancement in their skills in seismic-resistant constructions can significantly help in improving the earthquake resistance of informal, non-engineered buildings and hence considerable reduction in the loss of human lives and properties due to earthquake. To improve the construction qualities, training programmes are necessary for small contractors, masons and bar binders, equipping them with basic knowledge of earthquake resistant building construction technology and providing them with a clear and concise framework of earthquake-resistant construction technology. A standard training manual has been developed to produce new masons and bar binders as well as upgrade the skill level of those practising.
Poster and leaflet on earthquake vulnerability reduction measures: Disaster Management Bureau (DMB) has been working on upgrading the awareness and preparedness level of the city dwellers by producing booklets and other relevant documents. CDMP has also produced posters and leaflets on earthquake awareness while some academic institutions (BUET) and NGOs (Islamic Relief, Concern Worldwide, etc.) are also working to educate the people about what to do before, during and after earthquake.
The way forward
While there have been significant developments in the area of earthquake preparedness in the country, much remains to be done. This includes: formation of a well-equipped Earthquake Emergency Operation Centre (EOC), strong laws and building codes, proper monitoring mechanisms during construction of buildings, adequate measures to reduce structural and non-structural vulnerability of hospitals, schools and other critical infrastructure. Earthquake education from the household to institutions is crucial. The most important is institutionalising the preparedness and risk reduction activities within the relevant organisations. In the updated version of Standing Order on Disaster (SOD) approved in April, 2010, the responsibilities for earthquake preparedness and risk reduction of all the concerned ministries and departments have been clearly delineated.
Bangladesh is now considered the world leader in responding to cyclone and flood. However, we have no recent experience of responding to a major earthquake. We have a well-structured disaster management strategy in hand, but we need much more intervention to reduce earthquake hazard to address the long-term vision of the Government of the People's Republic of Bangladesh on disaster management: "to reduce the vulnerability of people to a manageable and acceptable level". We have made some encouraging progress, but there remains a long way to go. Disaster management is everybody's business. The present status of earthquake preparedness is not yet at the level of flood and cyclone hazard management. The work done so far by all parties has established a backbone for earthquake risk management; now we need to escalate these activities across all sectors.
Dr. A.S.M. Maksud Kamal is an urban risk reduction specialist working with Compréhensive Disaster Management Programme (CDMP) and United Nations Development Programme (UNDP).