Human and Institutional Perspectives of the 921 Earthquake in Taiwan: Lessons Learned
by George C. Lee, Director
Multidisciplinary Center for Earthquake Engineering Research
State University of New York at Buffalo
Chin-Hsiang Loh, Director
National Center for Research in Earthquake Engineering
National Taiwan University
On Tuesday, September 21, 1999, a devastating earthquake struck the central region of Taiwan. This earthquake became known as the 921 earthquake or the "Ji-Ji" or "Chi-Chi" earthquake. The magnitude of the 921 earthquake was MS = 7.6 (Richter scale) or ML = 7.3 (the system used in Taiwan). There were 10 aftershocks greater than magnitude 6. Of these, an ML = 6.8 occurred about 30 hours and 120 hours after the main shock, respectively.. An ML = 5.3 aftershock was recorded as late as 260 hours later causing collapses of already damaged structures. As of October 8, the death toll stands at more than 2,350. Over 8,700 people were injured, and dozens remain missing. Approximately 10,000 buildings/homes collapsed and over 7,000 more were damaged.
Taiwan has 49 known active faults. The one that ruptured is known as the Chelungpu Fault, which is approximately 70 km long and runs north-south located in the central region of the island. (The quake's epicenter was located at 23.85° N and 120.78° E at a depth of approximately 7 km. The average dislocation of an area of 70 km x 40 km was about 2.5 m (with a maximum dislocation on 6 m). The maximum horizontal acceleration recorded (thus far available) was approximately 0.99 g which is more than four times the designed value of 0.23g for buildings in this region.
The Multidisciplinary Center for Earthquake Engineering Research (MCEER) and the National Center for Research on Earthquake Engineering (NCREE) have had a research collaboration agreement to carry out fundamental earthquake engineering research in areas of mutual interest. A number of joint studies in the general area of seismic response control began after the first workshop in 1995. A second workshop was carried out in April 1999 in which two additional research projects were added (remote sensing applications, and protective systems for bridges). NCREE has a brand new research laboratory funded by Taiwan's National Science council. It is located at the National Taiwan University in Taipei. The lab has served as a focus point for many international professional reconnaissance teams since the earthquake, and provides updated information about this earthquake on the web (http://www.921ncree.gov.tw).
Shortly after the 921 earthquake, discussions between the authors led to the idea of an MCEER-NCREE workshop, which took place on October 3-5, 1999 in Taiwan. The purpose of the workshop was to identify important short-term strategies/actions for post-earthquake restoration and research needs, including specific cooperative projects for investigators from both centers to work as teams based on the 921 experience.
This article summarizes the observations and reflections of the authors after the three-day workshop in Taiwan with respect to the societal and government responses of the 921 earthquake. The authors are of the opinion that this earthquake not only destroyed a segment of Taiwans physical landscape, but also made a significant impact to the society and government. Taiwan, like the U.S., is lucky because it hasnt experienced a major destructive earthquake with large number of death tolls in recent memory. This 921 earthquake presents a reminder and an opportunity for the people and government in Taiwan to begin a serious effort to establish more resilient communities against future earthquakes.
Earthquake ground motions are felt by people living throughout Taiwan. Thus, the term "earthquake" is a familiar one. However, an earthquake of the magnitude of 921 has not happened in recent history. To many people, an earthquake amounted to the swaying of buildings and the development of cracks on a wall. Occasionally, the roof of some houses collapsed. The building code in Taiwan provides for reasonable design guidelines (the most recent update to the guidelines was made in 1997). Based on historical data and measurements made by strong motion instrumentation programs, the Taichung/Nantou area is classified as a region of moderate intensity with a design peak horizontal acceleration of 0.23 g. The 921 earthquake generated a horizontal force of more than four times this maximum design criterion. It is thus easy to see why so many buildings and bridges collapsed. Psychologically, the public in the area was accustomed to earthquakes, but not one of such destructive magnitude, occurring in built-up areas.
The public showed tremendous spirit as they worked together to save lives and help each other with the basic needs to survive in the days following the earthquake. After a day to two, many began to complain that the government was too slow in its rescue and relief efforts. As a few more days passed and people were forced to accept the loss of a loved one whose body had not yet been located, these complaints of ineptitude and inefficiency were understandably intensified. Nonetheless, it seemed that the government was actually quite swift and effectual in its response to the event, given its magnitude. At the same time, many people praised the efforts of military personnel and international emergency response teams, even though such help was limited in its effectiveness by the scarcity of critical information such as local area maps, building blueprints, and other such data. The disaster management effort at the regional and local level was clearly unprepared for this disaster.
In speaking with a variety of individuals, one can see that this earthquake has had an enormous impact on the way the public views the importance of building safety and location of both workplace and residences. In the short three-day visit, questions regarding these issues were the most frequently raised by the general public. Now is the time in Taiwan to emphasize public education on earthquake hazards and mitigation measures. A well-educated public will affect improvements in policy regarding mitigation and preparedness for earthquake and other natural hazards. In the past, real estate properties for many are the means to become rich. The landslides, the disappearance of the lake (reservoir), and the interrupted skylines in the city caused by the 921 earthquake had elevated the awareness of the public to treasure the small island shared by 22 million people. One may expect that environmental conservation and protection will be emphasized. Activities such as illegal pumping of fresh ground water for growing seafood (sinking land surface level) will be condemned by the public.
On the national level, the government seems to have responded well. It was certainly not possible to satisfy all those affected by the earthquake. However, many of the complaints stemmed from lack of preparedness rather than lack of emergency action. Within hours of the initial main impact, the national government announced policies for relief, short-term restoration and an organized interagency structure for efficient execution of rescue efforts. By September 28th (one week later), there were 17 major policies implemented, including hotlines, information and health centers, temporary housing, disaster relief funds and materials, and others.
However, a lack of earthquake disaster preparedness at both the national and local levels was evident. To varying degrees, this state of affairs exists everywhere in the world with respect to unexpected natural disasters. Because the occurrence of devastating earthquakes is probabilistic in nature, the consequences of such events are often not taken seriously by both the government and its constituents. In recent decades, the professional communities and government in Taiwan have made significant progress to mitigate earthquake hazards by, for example, funding the Strong Motion Instrumentation Programs at the Central Weather Bureau of the Ministry of Transportation and communication, and funding earthquake and earthquake engineering research projects by the National Science Council including the establishment of NCREE. The Ministry of the Interior and the various structural engineering professional organizations have also been active in updating building codes and the ministry of Education has been investing in human resources development and earthquake engineering facilities at the universities. Additionally, a National Science and Technology Program for hazard mitigation was established several years ago to coordinate the development of national hazard mitigation strategies.
All these efforts have been carried out by many talented researchers and administrators. They now beg the question "What difference did these programs make in the communities where the earthquake struck?" Other than building code improvements for recently built structures, very little can be said about how the investment of tax money improved the preparedness and resiliency of the communities. It seems that a systems approach involving multiple agencies and professionals at all levels from national to local must be designed and implemented. An effective institutional structure for earthquake hazard mitigation is needed to develop well-prepared communities. It is important, however, to distinguish between a comprehensive block diagram of relevant components (which is easy to draw) and a properly functioning hierarchy of agencies (which makes decisions at each level in a manner consistent with the overall system objectives).
Some Lessons Learned: Recommendations for Possible Actions
An earthquake resilient community should have three elements at its core:
- Properly developed codes for the physical infrastructure
- high quality professional practice in planning, design, construction and maintenance.
- An informed and participating public.
- An institutional infrastructure system prepared for mitigation and response.
All these points require long-term sustained commitment from both the government and its citizens.
The 921 earthquake offers a chance to learn from "real world experience." Many issues related to earthquake engineering, from both the research and practical sides, have been addressed in other reports co-authored by investigators from both NCREE and MCEER. Several reconnaissance teams have also issued technical observation reports (for example, the NSF-supported reconnaissance team, the EERI reconnaissance team, etc.). In this section, the authors reflect on their observations of the damage from the 921 earthquake and its effect on the local people, their community and government infrastructure and the level of public knowledge on issues of earthquake hazard preparedness. Other reconnaissance reports have paid special attention to earthquake engineering research opportunities and the importance of long-term professional practice dealing with the physical world. The following observations are made from the total perspective involving human, institutional as well as physical infrastructure system for which post-event actions may begin. They are offered for the public and the government in Taiwan as they face the restoration challenge after the 921 earthquake:
I. If the epicenter of the 921 earthquake had been located just 50 miles either North or South of the Taichung/Nantou area, the devastation to Taiwans economy and the quality of life would have been much worse. To the North, the high-tech industrial park in Hsin-Chu and the political and economic center Taipei would have been struck; to the South, the center of heavy industry and manufacturing KaoHsiung could have been destroyed or seriously damaged. Eventually, these areas will be hit with a major earthquake. The opportunity exists today to carry out careful loss estimation and risk assessment studies for these areas. Ground motion information, geotechnical and structural design information all exist in sufficient quantities to conduct credible analyses of possible earthquake scenarios. These results could have a significant impact on the general public, elected officials and other decision-makers and stakeholders in Taiwan. Many individuals and organizations have gained financially from the booming real estate market of the past several decades these groups will surely be supportive of such studies while the 921 earthquake is fresh in the populations collective memory. This type of study would allow for some quantification of the vulnerability of critical regions in Taiwan and could serve as the focus for a sustained effort in public education.
Many individuals directly impacted by the earthquake require psychological help, for which the government has implemented a program. Often, survivors of critical events (drunk driving car crash, recovery from a terminal disease, etc.) become the best crusaders. These individuals may be provided with adequate understanding of the issues involving earthquake preparedness so that they can contribute to the public education task.
II. There is an immediate need for reliable methods of evaluating the extent of damage to a structure so that proper decisions can be made with regard to retrofit/repair/replacement of the structure. More than 7000 damaged buildings (unconfirmed) remain standing in and around the epicenter and they all need critical assessment of the damage sustained. This is a significant opportunity to begin accumulating the knowledge about "building damage" by developing an "expert system" or standardized system of measures for non-destructive building evaluation. Of high priority is the evaluation of essential infrastructure buildings such as command centers, hospitals, manufacturing complexes and critical lifeline systems such as water, electrical power networks and bridges. An additional research effort to explore advanced technologies for deployment and implementation of emergency response, communication and rescue is also appropriate at this point, based on the lessons learned. There are many other long term research opportunities in earthquake engineering that will not be addressed in this article.
III. The current emergency management and restoration organizational structure was swiftly and rapidly established immediately after the earthquake. It should be replaced gradually by a long-term institutional infrastructure which involves agencies at all government levels concerning all types of hazards. But beyond a simple box diagram of the hierarchy, such system requires thoughtful implementation. One very important element is the appointment of the proper individuals at key positions in the various agencies (an Emergency Response Corps - the ERC). In an emergency situation, these individuals of the ERC are the connecting nodes of the system of agencies. They must be well versed in and loyal to the overall strategic and tactical aims of the system because they may be called upon to make decisions on short notice without the ability to consult either their superiors or their subordinates. These individuals would need to meet regularly, say twice a year, to review the emergency operating plan that should exist, and to update their coordinated efforts in mitigation and emergency preparedness including training and practice for emergency professionals. An institutional infrastructure for multiple hazard mitigation and response may be organized differently consistent with a countrys own system and culture. The system in the United States (Congressional hearings and actions, the NEHRP agencies, the lead agency FEMA and its regional office, etc. and how they function) can be used as a starting point for development.
In general, a functioning institutional infrastructure system is much more difficult to establish than to reconstruct the physical infrastructure system. The latter may be targeted to complete in three or five years if resources are available. Emergency response and short-term actions require a top-down approach. But for long term re-establishment, the top-down approach must be coupled with the bottom-up efforts of the participation of well-educated public. The government must consider the current emergency management organizational structure as the beginning of a sustained pursuit, not as a one-shot event. One action to enhance the bottom-up effort is to define the responsibilities of elected district administrators (county executives, town supervisors, etc.) to maintain inventory of the physical environment in the district and be knowledgeable of the issues making the district more resilient.
IV. One of the most pressing issues in short-term restoration is that of construction quality. This has always been an ill-defined factor that makes the evaluation of existing damaged facilities more difficult. It also becomes a factor of importance in the time immediately following an earthquake, as reconstruction begins. Other issues such as public education, research, institutional effectiveness and building code improvements are longer term efforts. However, working with the real estate and construction industry can and should begin immediately with the restoration efforts. A workshop might be organized to review the current practice in building inspections (see item 2 above) and construction monitoring. Additional guidelines or recommendations would be issued as necessary. Building inspection and construction quality assurance should be examined from the overall perspective of planning, design, construction, decision-making processes (in the case of public works) and cost.
V. The short-term and long term research needs identified by the 921 earthquake indicate that most of the research programs of MCEER and NCREE, particularly those involving current and potential joint MCEER-NCREE research efforts in loss estimation and risk assessment, in developing retrofit strategies for critical facilities (water and electric power networks, medical facilities and bridges) and in application of advanced technologies in structural response mitigation and emergency responses can benefit from the real world experience of the 921 earthquake, and at the same time make a contribution to the state-of-the-art of earthquake engineering practice both in Taiwan and US. We look forward to a success story resulting from this center-to-center cooperation enhanced by the 921 earthquake.