October 2005
abstract
Responsabilité & Environnement
Natural disasters
Issue 40
Editorial
By François Valérian
Tectonics, the current source of major earthquakes
By Paul Tapponnier
Physicien, Laboratoire de tectonique, Institut de physique du globe de Paris
Cataclysms have made millions of casualties during the past century. We now have the ability to predict major earthquakes and thus take measures in advance. For the most part, only major earthquakes are unforeseeable. Why? What we know, what we can do and how to advance toward making short-term predictions…
Volcanic risks
By Claude Jaupart
Institut de physique du globe de Paris
Volcanos still erupt, killing people. Major eruptions can affect the climate and thus have an impact on the population all over our planet. Vulcanology has made progress in both theory and observations during the past three decades. What point has the discipline reached? What can now be predicted? What hopes for the future?
Understanding and preventing tsunamis: Input from numeric simulation
By Hélène Hébert, François Schindelé, Anthony Sladen
Département Analyse surveillance environnement CEA Bruyères-le-Châtel
The tsunami that struck Sumatra in December 2004 has aroused a new, global awareness of such risks. This is going to stimulate prevention work. It will enable those who design models to experiment with methods and test them against the vast body of available data. At stake: improve the planning and development of coastlines; intervene so as to manage alerts; and better understand the physics of tidal surges, of their production, propagation and impact on coastal areas.
Landslides: Assessing the risks
By Anne Mangeney
Institut de physique du globe de Paris
Who has not walked on, lived in or drove over what was left from a landslide or subsidence without even knowing it? The theoretical description and understanding of the physics involved in these processes is still wide open. Tackling this question entails understanding a major factor in the evolution of a planet’s surface — the dynamic forces whereby matter shifts and is stocked. Beyond these theoretical aspects, a framework for managing risks must be adopted.
Contingencies and risks in geographical analyses
By Yvette Veyret, M. Reghezza
Laboratoire Gecko, Université de Paris X-Nanterre
In France, geography used to be part of the natural sciences before it shifted its grounds to the social sciences. Following in the footsteps of American geographers who, in the early 20th century, started focusing on the “facts” of both nature and society, French geographers now, as they study contingencies and risks, insist on risk exposure and on the relations between risks, place and territory. Now discontinuous, “territories” are becoming more vulnerable as they are hooked up in networks.
Scenarios, a tool for taking into account seismic risks: The example of Nice
By Pierre-Yves Bard
Laboratoire de Géophysique interne et tectonophysique (LGIT)
Anne-Marie Duval
Laboratoire régional des Ponts-et-Chaussées
Patrice Foin
Conseil général des Ponts et Chaussées
Philippe Guéguen
Laboratoire de Géophysique interne et tectonophysique (LGIT)
Etienne Bertrand
Laboratoire régional des Ponts-et-Chaussées
Jean-François Vassiliades
Laboratoire régional des Ponts-et-Chaussées
Sylvain Vidal
Laboratoire régional des Ponts-et-Chaussées
Christian Thiblault
Laboratoire régional des Ponts-et-Chaussées
and François Dunand
Laboratoire de Géophysique interne et tectonophysique (LGIT)
The French Riviera lies far removed from Japan or California, but the risk of an earthquake is quite high there. Nonetheless, prevention work still runs up against a low awareness of the dangers. For this reason, and as has been successfully done in countries facing higher risks, scenarios have been designed to draw up prevention policies. Here are the major points figuring in the Gemgep Project, the most recent study conducted in Nice, France.
Expertise for preventing natural risks: The Séchilienne rockslide
By Michel Bart
Préfet de l'Isère
Beyond expected technical analyses and the advances made in our knowledge of risks and of the means for preventing natural disasters, a scientific task force has stimulated an awareness of dangers. It has thus moved actors to react — thanks to exemplary work in terms of methods and results, and thanks also to a transparent, educational approach involving a dialog. Though not replacing action, this expertise does make it possible to take actions: the case of the Séchilienne rockslide in Isère department, France.
Typology of risks and scientific knowledge about risk exposure: The engineer’s viewpoint
By Jean Dunglas
Ingénieur général honoraire du Génie rural des Eaux et des Forêts
Volcanos, cyclones, earthquakes, floods, landslides, tsunamis… our knowledge of these phenomena is growing fast. But for scientists and engineers, there is still plenty of room for progress in understanding risks and risk-exposure. It is senseless to imagine that we can avoid all natural catastrophes. However, better understanding the processes involved means improving our knowledge of how to protect ourselves. This challenge is all the more urgent given the rapid urbanization of our planet’s population.
Federal agencies knew that New Orleans was menaced: Drills and evacuation plans were useless
By Scott Shane, Eric Lipton
in International Herald Tribune, 3-4 septembre 2005
Katrina should not have taken officials, whether federal or local, unawares. The hurricane had been expected for several years. Evidence of this are the hundreds of thousands of dollars spent on the likes of studies, drills and emergency plans. Nonetheless, the conclusions drawn were uncertain; and authorities have been unable to respond to the need to provide shelter to thousands of people, or to evacuate those who could not leave on their own.
Let Katrina be a warning…
By John Carey, Lorraine Woellert, Eamon Javers, Otis Port
on BusinessWeek online, 1er septembre 2005
Katrina’s devastating effects were perfectly foreseeable and… avoidable. Beyond the controversies about unheeded warnings or policy shortcomings, lessons are to be drawn with regard to how we manage energy and natural resources.
Do natural catastrophes still exist?
By Jean-Pierre Dupuy
Ecole Polytechnique Paris et université de Stanford
How could Katrina, the hurricane of 29 August 2005, be compared with the terrorist attack of 11 September 2001? Because we thought people were somehow responsible for the devastation. Because Western science, underlaid by religion, has gradually pushed the bounds of human actions outwards — till the ultimate, outermost limit of an alien, powerful. Coming droughts, cyclones or tsunamis will, therefore, be the unexpected outcome of our actions.