Introduction:During the past decades, Nepal has progressed significantly in the area of emergency preparedness by providing earthquake awareness programs to general public, initiating disaster response plans, developing health sector preparedness and awareness about safety measures in school education programs in order to combat the enormous potential disaster from future earthquake hazards.   Recently, on October 11, 2009, the Nepal government approved a National Strategy on Disaster Risk Management, which deals with the mechanisms needed for preparedness, response, and recovery from any disaster. The mechanisms include, but not limited to providing compensations and rehabilitation to the affected communities and infrastructure impacted by this natural disaster.

Every year since 1999, Nepal is also observing "The Earthquake Safety Day" on January 16th by organizing various earthquake awareness programs in Kathmandu, and lately in other parts of the country as well.  This is intended to remind people about the catastrophic earthquake of 1934, and the subsequent earthquakes occurred in various parts of the country and to make them aware of the need for advance preparation for such disasters. 

Brief History of Earthquakes in Nepal and Current Assessment

The 1934 earthquake of magnitude 8.25 in the Richter scale had devastated the entire Kathmandu valley and had caused a huge loss of human lives and properties throughout the country.  An earthquake monument at Bhugol Park in New Road, Kathmandu reminds the disaster caused by this earthquake.  Lately, the 1980 earthquake of Magnitude 6.5 and the 1988 earthquake of magnitude 6.6 had also caused a significant loss of human lives and properties in the country.  These earthquakes have greatly helped create general awareness among the government authorities, engineers and the scientists from various professional organizations in Nepal, to seek various ways and means in order to save the loss of lives and properties caused by potential future earthquake hazards.  In 1994, the Ministry of Physical Planning and Works published the first building code in Nepal, titled "Nepal National Building Code."

According to United Nation's study, Nepal is placed top 11th in the ranking of earthquake-prone countries. The whole length of Nepal, from east to west, lies in an active shallow earthquake belt.   Nepal is also placed in a zone that has the highest probability of risk and the greatest potential of major damage of buildings and infrastructure during an earthquake episode, and is more or less comparable to California.  Geologists believe that Kathmandu is built on the soft sediment of a former lakebed, (even historically, it's said that Kathmandu Valley was, one time, a big lake surrounded by the mountains), which contributes to a higher level of earthquake risk in the valley.

Kathmandu Valley Earthquake Risk Management Action Plan has estimated that up to 40,000 could lose their lives and close to 100,000 injured if an earthquake similar to that of 1934 occurred.  Also, it is estimated that around 60 percent of the houses in the Valley would be severely damaged, many beyond repair. In addition, the National Society for Earthquake Technology - Nepal (NSET) established in 1996 to provide the necessary services, including providing training to masons and craftsmen, in the area of earthquake preparedness, risk management plans and general awareness programs; and the Geo Hazards International, USA have predicted that 95% of the water pipes and 50% of the pumping stations and treatment plants could also be seriously affected hampering water supplies for several months. Also, half of the bridges and many narrow streets/roads in the Kathmandu Valley could be impassable due to damage and debris.  In hilly regions, it is obvious that landslides may occur at various places and transmission towers and telephone lines may collapse blocking the roads.  This may make many areas inaccessible, making the rescue and emergency operations a Herculean task. The earthquake disasters are known to trigger fires in the community; houses are being burnt making the post-earthquake operations even more challenging.

Learning Lessons from Recent Earthquakes in Haiti and Chile

The Nepali Diaspora in USA and around the world is very much alarmed from the recent Haitian Earthquake of January 12, 2010 (Magnitude 7.0) and the Chilean Earthquake of February 27, 2010 (Magnitude 8.8).  The Haitian earthquake took 200,000 human lives in a population of 20 million; roughly half of the buildings in Haitian capital, Port-au-Prince, have been destroyed, and 1 million people became homeless.  The island nation must rebuild from ground up.  News indicates that the devastation caused from the recent earthquake in Haiti was worsened by shoddy building construction due to lack of building standards. Haiti does not have a national building code.  Engineers and Architects in Port-au-Prince discuss that the first step to rebuilding Haiti would be also to set up a national building code. On the contrary to the Haitian's tremendous loss from the earthquake disaster, engineers and scientists state that an adherence to strict building codes helped prevent a higher death toll from Chile's earthquake of a much bigger magnitude than that of Haiti. 

Building Code for New Construction

Nepal does have a building code since 1994. However, it is widely believed that the code needs to be updated at appropriate intervals to keep abreast with the current research and development in the structural design and analysis, construction industries with new construction materials, and the state-of-the-art technological advancement nationally and internationally. The building code requirements need timely update even to incorporate the experiences gained and the lessons learned in using the codes from previous code-cycle. In USA, the building codes are updated every three years, and currently the International Building Code 2006 is in use. Being located in a highly active earthquake zone, it is necessary that Nepal's building code also see the frequent updates and follow the general code development process suitable to the nation's need for earthquake resistant design of building and infrastructure.

The building code normally outlines the necessary minimum design and construction standards that are required to meet the earthquake-resistant building criteria. Certainly, following the appropriate earthquake resistant building code helps reduce the damage and collapse of buildings, and hence the losses and damages that would have caused by such collapse. However, it is important to realize that to enhance the greater safety of the building occupants and the general neighborhood from an earthquake disaster, it is essential that along with the adequate building design and construction codes, various other codes dealing with the electrical, plumbing, heating, ventilation and air-conditioning, fire-safety, elevators, stairs, and the exiting and evacuation system requirements are developed and implemented in the development projects.

The building code mandates only the minimum design criteria that are required to prevent a sudden collapse of the building in a major earthquake. The buildings are not designed to be fully earthquake-proof; due to the obvious reason that they will be very expensive and prove to be economically not feasible. Consequently, the building can have damages that are easily repairable. By preventing the building from collapse, the occupants can easily be evacuated and rescued. However, all essential facilities including schools and hospitals are designed with a higher design safety criteria because they are occupied by children and patients respectively, who need special assistance for evacuation and rescue, unlike other able people.

Code for Retrofitting Existing Buildings

The building code covers only the design of new buildings and does not address the procedures and norms required for retrofitting the existing buildings. Kathmandu Valley has full of old unreinforced-masonry buildings, low and mid-rise in height, built mostly prior to the publication of the 1994 Nepal Building Code. They are therefore significantly vulnerable to damage, even collapse, in case of a major earthquake occurrence. This demonstrates an immediate need for developing a separate building code to address the retrofitting design standards and criteria for both the existing historical and non-historical buildings in Nepal. In USA, The Uniform Code for Building Conservation is used in general for such purpose. However, different cities have also developed their own criteria to retrofit the existing buildings in order to make them stronger and prevent them from collapse during earthquakes. The major portion of the existing old buildings in Kathmandu valley and outside the valley were built using simply out of burnt or un-burnt clay bricks laid in mud mortar combined with structural wood members.  These types of buildings do not have much lateral-load-resisting abilities to respond to the loads generated by major earthquakes.  Depending on the various seismic and geological conditions of the site, these buildings can crumble or collapse, sometimes even in a moderate earthquake. Similarly, in other existing and new buildings, the unreinforced walls (out of plane failure) might be more vulnerable to earthquake damage, as is evident from past earthquakes in the world.

Conclusions

In conclusion, it can be said that to lessen the loss of life and properties, it is vital for earthquake prone countries, like Nepal, to have an adequate earthquake resistant building design codes for constructing new buildings as well as retrofitting and repairing old buildings. It must also be added that it's not only enough to make the individual building safe from earthquake disaster, but the full spectrum of infrastructure, e.g., roads, bridges, airports, telecommunication and electrical towers, water and all utility lines, which are the lifelines for the community, must be built earthquake-safe.  Nepali Diaspora should come forward to share their knowledge and experience gained internationally with their colleagues in Nepal. In this effort, a joint initiative led by three voluntary engineering/scientific/medical organizations, American Society of Nepalese Engineers (ASNEngr), American-Nepal Medical Foundation (ANMF), and Computer Association of Nepal (CAN)-USA in order to prepare a position paper for earthquake preparedness and disaster relief for Nepal is recently being launched. As of now, sixteen Nepali Diaspora organizations in the U.S including Association of Nepalis in Americas (ANA), Association of Nepalese in Midwest America (ANMA), Nepalese Association in Southeast America (NASeA) and Non-Resident Nepali National Coordination Council (NRN NCC) of USA, and one prominent organization in Nepal - National Society for Earthquake Technology (NSET) - Nepal have committed/shown willingness to support this initiative. As the project moves ahead, it is expected that more Nepali Diaspora and other organizations worldwide will come forward to support this worthwhile cause.

(Kanhaiya Kayastha is a California licensed Consulting Civil and Structural Engineer, and Vice-Chair of the Technical Committee and Fellow (Life) of American Society of Nepalese Engineers (ASNEngr) and can be reached at kkayastha@aol.com .)

(Dr. Ramesh B. Malla is an Associate Professor, Department of Civil & Environmental Engineering, University of Connecticut, Storrs, CT, U.S.A. and Founding President and Fellow (Life) of the American Society of Nepalese Engineers (ASNEngr) and can be reached at MallaR@engr.uconn.edu )