Urban seismic risk management: A methodology

Hammoud Zelloum

Laboratoire du Bâti dans l’Environnement (LBE – FGC/USTHB), Université des Sciences et Technologie Houari Boumediene (USTHB), Alger, Algeria, University of Architecture, Civil Engineering and Geodesy, Sofia, Bulgaria.

E-mail: hamoud_z@yahoo.fr

Accepted 15 October, 2009

   Abstract

This research work presents a methodology for urban seismic risk reduction and illustrates the implementation to the methodology proposed to the site of Bab El Oued in Algiers (Algeria). The main goal is to reduce seismic urban risk at the site considered in Algiers. The seismic risk to which of more the urban centers are exposed became a world phenomenon. A significant element is the population. According to the last statistical data of the United Nations, the urban population is multiplied by twenty (20) times whereas the world population only by four (4) times. In the developed countries, 75% of the population lives in the cities, (concentration within the mégapoles: 20 amongst them exceeded the 10 million inhabitants). The main reasons of this attraction towards the city are misery, isolation of the rural areas and the movement towards the welfare of the city (Morand-Deville J., 2005). The beginning of the 21st century is marked by an acceleration of the major risks related to the natural hazards such as earthquakes. This constitutes the greatest challenge today for the scientists and the authorities. Lately the frequency of earthquakes occurrence, all over the world , challenge the decision makers and the scientific community towards a particular attention directed to the design, not only to the structures of the buildings but also to space planning and organization of the city with the aim of risk reduction. A co-operation on a worldwide scale is necessary for exchange of information and experience for the prevention and implementation of management plans and actions in the countries prone to this phenomenon. The seismic risk is as much crucial than it is necessary even of fundamental importance for the scientists to define which are the tools and the methods to provide for the various stakeholders in the act to conceive or to manage the city, namely the architects, the town planners, the developers, the engineers and the authorities in order to be able to insert the problems of the risk reduction in all the steps related to planning and city management. Seismic risk prevention constitutes an essential component of the operation of modern societies. The precondition to any prevention policy one needs is a clear-sighted examination and responsibility for all the actors concerned. This research work presents a new method for urban seismic risk reduction based on the application of an interdisciplinary work integrated in a dynamic and evolutionary process of the city planning when designing urban sites. This will clarify the aspect of prevention and management of the local risk, the vulnerability of the site and the use of the zoning, which is a dominating aspect in the risk reduction. This will encourage the decision makers and the local authorities as well as the civil society to have a local and permanent follow-up organization of the site (built, open spaces, lifelines, various networks etc.) and of a program for intervention such as simulations of an earthquake as a training tool of the population living in the territory at risk. The findings using this method are defining the safe shelter areas for the disaster victims and to redesign the road system for the access of relief, water and food supply, and a safe evacuation of wounded towards the health care establishments for a better risk management based on sound scientific research.

Key words: Risk, seismic, management, urban prevention planning, vulnerability.