Background

The Central American region is highly vulnerable to a wide variety of natural hazards, which constitutes a major challenge to its sustainable socioeconomic development.  In consequence, in recent decades, risk management policies have evolved to become more proactive, focusing on risk prevention and reduction.

As regards the seismic phenomenon, the San Salvador Metropolitan Area (AMSS) has been impacted by major earthquakes that resulted in loss of life and property, with impact on the country’s growth and economy.  The most recent events, in 1986 and 2001, make evident the city’s high vulnerability, which stems especially from poor planning and poor oversight of application of existing seismic-resistance standards.

In defining activities for disaster risk reduction, an assessment must be made of the potential impact on infrastructure of different events and, to that end, better knowledge gained of the hazard and level of exposure of exposed elements, as well as better assessment made of expected loss or damage.  The Ministry of Environment and Natural Resources (MARN), aware of the needs for assessment of maximum probable losses of health and education structures, has requested support from the World Bank to develop probabilistic seismic risk models for some portfolios through the use of the CAPRA technological platform, and to build institutional capacities for risk assessment and for the design and implementation of vulnerability reduction measures.

In view of the situation described above, a technical assistance project (TAP) is now in execution, whose main goal is to build institutional capacities for probabilistic seismic risk assessment through analysis and evaluation of the health and education portfolios of the AMSS.  Under the TAP, activities are being carried out to compile and analyze seismic hazard and local impacts, as well as data on health and education infrastructure, identify vulnerability curves for each existing structure, and assess maximum probable physical and economic losses resulting from potential seismic events. One output will be a seismic risk reduction program for the AMSS, to be implemented by the Ministry of Environment and Natural Resources (MARN) in coordination with the Ministry of Education (MEDUCA) and Ministry of Health (MINSA).

Achievements

Compilation and analysis of the seismic hazard and site impacts 

Several regional studies of seismic hazard that include El Salvador have been prepared, with data on San Salvador’s geological and geotechnical characteristics and accelerographic records obtained at different points around the city during past seismic events.  For execution of the TAP, it was necessary to compile, analyze, and identify soil and seismic hazard parameters and transfer functions to create an .ame file for modeling through CAPRA. This activity was led by MARN.

Identification of exposed elements of the education and health portfolios

In order to characterize health and education structures, the respective ministries have conducted a thorough survey of data on 352 healthcare facilities and 1052 education structures and 148 governments buildings in the AMSS. Much of the data has now been organized for modeling with CAPRA.

Establishment of vulnerability functions and assignment to exposed elements

The country had not prepared representative vulnerability curves for the construction typology of health and education infrastructure.  Therefore, research had to be carried out on vulnerability functions prepared in other countries that could be used for the seismic risk modeling.  With ongoing advice from the consultant group hired by the World Bank, the responsible officials of the ministries selected the curves to be used in the seismic risk model. This activity is now in its final stage and the formats required for use with CAPRA are being adjusted.

Probabilistic seismic risk assessment

This activity seeks to integrate, through the CAPRA-GIS platform, knowledge of hazard, exposure, and vulnerability to determine probable physical and economic losses for the portfolios analyzed.  At present, MARN is conducting pilot tests in specific areas of the AMSS. 

Seismic risk reduction program for health and education infrastructure in the AMSS

One of the essential outputs of the TAP is a seismic risk reduction program prepared as guidance for the Government of El Salvador in investment projects required in the short, medium, and long-term to obtain better knowledge, establish prevention and mitigation activities, and identify possible financial instruments for seismic risk reduction. Thus far, the MARN has identified actions for incorporation in the program.  However, based on the results of the CAPRA modellings, required action priorities will be set.

The main objectives that were identified in the program are targeted at:

• Safe location: Reducing risk (existing and future) resulting from poor location of structures in relation to existing hazards.
• Safe construction:  Reducing risk (existing and future) resulting from inadequate design and/or construction of structures vis-à-vis the requirements of the area. 
• Safe operation:  Reducing risk (existing and future) resulting from flows of services (operation and environmental impacts).

The technical assistance project ended in March 2012.