The aftermath of an earthquake in Kathmandu
Suitability of open spaces for emergency shelter.
In an international collaboration between German and Nepali scientists a new tool was devised to identify emergency shelter sites in Kathmandu’ open spaces for a planned earthquake scenario. The methodology rates open spaces according to capacity and access to services and was developed to facilitate shelter planning in case of a major earthquake that could hit the city. The research results and tool for a postulated event was placed into a real context following the M7.8 earthquake that struck the country on April 25.
The method, Open Space Suitability Index (OSSI), was developed by scientists from the Center of Disaster Management and Risk Reduction Technology (CEDIM) at Karlsruhe Institute of Technology (KIT) and the South Asia Institute (SAI) of Heidelberg University in Germany in collaboration with experts from the National Society for Earthquake Technology (NSET). Details of the methods were published in the Journal of Natural Hazards and Earth System Sciences in March of 2015.
The OSSI ranks shelter sites based on their capacity, availability of services, environmental conditions and accessibility, and combines these criteria to develop a holistic assessment of post-disaster risk. It covers physical damage projected for a certain place and the social circumstances of affected people. The methodology focuses on "pre-event planning and preparedness for emergency shelter placement" to identify the most appropriate locations for emergency shelters to help coordinate aid organisations' responses after disaster strikes.
A map representation of OSSI shows, for instance, the distribution of building blocks that have an open space accessible nearby that can serve as a shelter, compared to blocks without such spaces (see figure). The methodology computes shelter demand for a list of approved shelter sites identified by the International Organisation for Migration office in Nepal.
Population displacement is driven by damaged buildings, utility outages and other forms of building inhabitability, but is also aggravated by socio-economic vulnerability. The "backbone" of the shelter capacity analysis is a shelter demand model developed by Bijan Khazai at KIT which computes shelter needs for an input earthquake as a function of the number of people in unhabitable homes as well as a number of factors influencing people’s decision to seek public shelter. In Kathmandu this includes densely built urban areas where there is little open space, and a greater portion of the displaced population is likely to take up shelter on designated emergency shelter sites rather than their own property or nearby areas. Another important factor is areas with less possibility for outward migration as the residents are homeowners and not working migrants. Thirty-five percent of the populations aged 5 years and above in the Kathmandu Valley have migrated from other places.
The study’s results estimated that if a Magnitude 8.0 planned scenario earthquake occurred in the middle of Nepal, 50 percent of the buildings in the Kathmandu Valley would be heavily or partly damaged. This led to an estimate of the 342,300 persons likely to seek shelter in open, public spaces within Kathmandu Metropolitan City, and found that in the event of a disaster, only 253,900 can be accommodated in the designated emergency shelter sites.
While information on damage extent from the recent M7.8 April 25 earthquake in Nepal is still unclear, from initial reports we know that the damage rate in the Kathmandu Valley was well below the anticipated 50% rate and few of the newer buildings in the rapidly expanding capital appeared to have been damaged. Most of the reported damages have been observed in earthen-mud, stone and adobe buildings. The lower than expected damage rates from the recent earthquake is a current subject of investigation for scientists at CEDIM from both GFZ and KIT.
The recent earthquake did however confirm experience from many past earthquakes, such as the Gujarat (in India) and Pakistan earthquakes, which show that whenever possible people seek temporary shelter in nearby spaces, not big spaces far away from their home. Despite the heavy rains, many people in Kathmandu whose homes were undamaged still preferred to shelter in make-shift arrangement outdoors due to fears of aftershocks. Thus, the numerous smaller areas like courtyards and schools that are difficult to manage are serving as important first shelter sites, while the16 open spaces currently identified by the Government among the approved sites around Kathmandu remain sparsely populated. Within these sites, there are concerns of overcrowding with lack of access to basic services. The collaboration between KIT and Heidelberg University is continuing its research and is currently seeking to monitor the evolving situation bringing in the help of the Heidelberg Crisis Mappers. Together they are coordinating a shelter mapping program with the Kathmandu Living Labs and Humanitarian OpenStreetMap community to map and analyze the smaller shelter sites with respect to accessibility and availability of services.
The collaboration between the two German universities was made possible through the HEIKA program, which aims to bring together complimentary expertise from the Karlsruhe Institute of Technology and Heidelberg University. In this case the HEIKA “Integrated Earthquake Risk Assessment for the Himalayan Region” project bridges engineering and risk modeling capabilities at the Center for Disaster Management and Risk Reduction Technology (CEDIM) at KIT with expertiseon GIS and socio-cultural and economic vulnerability mapping at the South Asia Institute (SAI) of Heidelberg University to be able to adequately describe the risks people, businesses and governments face in earthquakes.
In responding to the April 25 earthquake in Nepal the collaboration was extended to a larger team of scientists from KIT and Heidelberg University in the frame of the CEDIM Near Real-time Forensic Disaster Analysis which aims to rapidly integrate scientific analysis with information and data emerging in disaster situations. The close collaboration between KIT and Heidelberg has already produced an initial FDA report issued on April 27th only two days after the event, and a second report focused specifically on the shelter response issued on Tuesday, May 5th.
Anhorn, J. and Khazai, B.: Open space suitability analysis for emergency shelter after an earthquake, Nat. Hazards Earth Syst. Sci., 15, 789-803, doi:10.5194/nhess-15-789-2015, 2015.
The Center for Disaster Management and Risk Reduction Technology, CEDIM, is an interdisciplinary research institution of the German Research Centre for Geosciences (GFZ) and the Karlsruhe Institute of Technology (KIT).