Gherardi M.

Gherardi M.
Paul Valéry University, Montpellier 3 · Géographie

About

31
Publications
14,851
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
139
Citations
Introduction
Featured research
Article
Full-text available
En contexte post-catastrophe les moyens aériens représentent une solution efficace pour agir avec rapidité dans un environnement dévasté. Parmi ces moyens, la flexibilité, l'atout économique et les possibilités que peuvent offrir les aéronefs télépilotés, aussi appelés drones, notamment en termes de reconstitutions 3D et de cartographie, en font un outil d’investigation alternatif en pleine expansion. Cinq applications de ces relevés par drone sont illustrées dans cet article suite au passage de l’ouragan Irma sur les Antilles françaises du Nord en septembre 2017 (Saint-Martin et Saint-Barthélemy). Elles permettent non seulement d’illustrer les potentialités techniques et scientifiques de ces nouveaux outils et des modalités de leur mise en œuvre, mais aussi de discuter de leurs limites dans le cadre de retours d’expériences post-désastre. Les résultats obtenus sont multiples et à forte valeur opérationnelle pour la prévention des risques cycloniques. Ils concernent l’analyse spatiale des dispersions de débris et la reconstitution des volumes associés, la fiabilité des estimations de dommages sur les bâtiments, le suivi du processus de reconstruction, et la compréhension des impacts géomorphologiques sur le littoral. Mots-clés : Drone, Cyclone, Irma, Catastrophe, Antilles, Retour d’expérience In post-disaster context, air assets represent an effective solution to act quickly in a devastated environment. Among these means, the flexibility, the economic advantage and the possibilities offered by Unmanned Aircraft System, also known as UAS, particularly in terms of 3D reconstructions and cartography, make them an alternative investigation tool that is rapidly expanding. Five applications of these UAV surveys are illustrated in this article after the passage of Hurricane Irma over the French North West Indies in September 2017 (Saint-Martin and Saint-Barthélemy). They illustrate the technical and scientific potentialities of these new tools, the modalities of their implementation, and give us also the opportunity to discuss about their limitations in the context of post-disaster feedback. The results obtained are multiple and offer a high operational value for the prevention of cyclonic risks. They concern the spatial analysis of debris dispersal and the reconstruction of associated volumes, the reliability of damage estimates on buildings, the monitoring of the reconstruction process, and the understanding of geomorphological impacts on the coastline. Keywords: UAS, Hurricane, Irma, Disaster, Antilles, Experience feedback
Article
Full-text available
The objective of our study is to establish an assessment of four volcanic hazards in a country threatened by the eruption of the OlDoinyo Lengai volcano. The last major eruption dates back to 2007-2008 but stronger activity in 2019 has revived the memory of volcanic threats to the Maasai and Bantu communities and human activities (agro-pastoral and tourism). The methods chosen have had to be adapted to the scarce and incomplete data. The volcanic hazards and their probability of occurrence were analysed on the basis of data available in the scientific literature and were supplemented by two field missions combining geography and hydro-geomorphology. Our study enabled us to map the hazards of ash fall, lava flows, lahars and avalanches of debris. Each hazard was spatialised by being ascribed an intensity. hey are sometimes synchronous with the eruption sometimes they occur several months or years after a volcanic eruption. The results are the first step towards developing a volcanic risk management strategy, especially for the pastoral communities living around Lengai and for the growing tourist activities in this area.
Article
Full-text available
The intense hurricane season of 2017 in the North Atlantic brought a number of major hurricanes including Hurricane Irma (cat. 5), which landed on the French islands of St. Martin and St. Barthélemy. These two French Overseas Collectivities, separated by a distance of some 20 kilometres, have very different territorial and social characteristics. The study reported in this article is part of a scientific feedback conducted a few weeks after Irma. The social approach to the disaster conducted within this research framework aims to characterise the behaviour and implications of the inhabitants in the experience of the event, placed in a social and territorial context thanks to narrative interviews administered in situ. The comparative approach reveals similar behaviour before and during the hurricane, but individual and collective social and territorial factors guided very distinct post-event reactions.
Book
Full-text available
Le projet TIREX (Transfert des apprentissages de retours d'expérience scientifiques), dirigé par Pr. Frédéric LEONE, part du constat que les résultats des retours d'expérience scientifiques ne sont pas assez communiqués aux acteurs des territoires concernés. En analysant la saison cyclonique 2017 dans les Petites Antilles, TIREX répond à la fois à une demande scientifique visant à mieux comprendre les mécanismes et facteurs de production d’une catastrophe sur des territoires insulaires, ainsi qu'à une demande sociétale et institutionnelle d’apprentissage des leçons des catastrophes pour anticiper l’adaptation aux effets de futurs épisodes climatiques extrêmes. Ce projet est porté par un groupement scientifique de métropole et des Antilles, à forte composante universitaire en sciences humaines et sociales, spécialiste des régions étudiées et de la gestion des risques et catastrophes. Il associe également deux directions interrégionales de Météo-France, ainsi qu'un acteur privé, la Caisse Centrale de Réassurance. A travers cette synthèse, le projet TIREX tend à capitaliser, valoriser et transférer les acquis scientifiques du retour d’expérience vers des partenaires locaux, au premier rang desquels les collectivités de Saint-Martin et Saint-Barthélemy, des 31 communes littorales de Guadeloupe, des trois préfectures concernées, et de l’Etat- Major Interministériel de Zone Antilles (EMIZA).
Article
Full-text available
The hurricane season 2017 in the North Atlantic was intense. The events recalled the exposure of the West Indies to these phenomena sometimes devastating, such as the cyclone Irma which caused heavy losses on the French islands of Saint-Martin and Saint-Barthélemy. The post-event phase sometimes gives rise to an experience feedback (RETEX), which reports on the steps and management processes of the event. RETEX is widely conducted with institutions but leaves to hear the people. This study is based on a scientific RETEX in which the individual dimension of crisis management is integrated, by asking to what extent do individuals participate (or not) in crisis management (directly and indirectly) and how? The scientist team went to meet populations to assess how they lived and prepared themselves to cope with TC Irma in order to present the invest of populations in crisis management. The acknowledgment of populations about natural hazards is fine, and they also know recommendations to cope with cyclone. However, TC Irma was more strong that the reference event (Luis in 1955) for which the populations were prepared. Damage revealed and/or increased existing vulnerabilities which raise the question of built back processes.

Publications

Publications (31)
Article
Full-text available
En contexte post-catastrophe les moyens aériens représentent une solution efficace pour agir avec rapidité dans un environnement dévasté. Parmi ces moyens, la flexibilité, l'atout économique et les possibilités que peuvent offrir les aéronefs télépilotés, aussi appelés drones, notamment en termes de reconstitutions 3D et de cartographie, en font un...
Article
Full-text available
The objective of our study is to establish an assessment of four volcanic hazards in a country threatened by the eruption of the OlDoinyo Lengai volcano. The last major eruption dates back to 2007-2008 but stronger activity in 2019 has revived the memory of volcanic threats to the Maasai and Bantu communities and human activities (agro-pastoral and...
Article
Full-text available
The intense hurricane season of 2017 in the North Atlantic brought a number of major hurricanes including Hurricane Irma (cat. 5), which landed on the French islands of St. Martin and St. Barthélemy. These two French Overseas Collectivities, separated by a distance of some 20 kilometres, have very different territorial and social characteristics. T...
Article
Cet article explore les relations entre les caractéristiques territoriales et les capacités de relèvement d’une petite île caribéenne, confrontée à un événement cyclonique exceptionnel : Saint-Barthélemy face à IRMA (sept. 2017). L’analyse repose sur l’acquisition de données récoltées in situ dans le cadre d’un retour d’expérience (RETEX) scientifi...
Book
Full-text available
Le projet TIREX (Transfert des apprentissages de retours d'expérience scientifiques), dirigé par Pr. Frédéric LEONE, part du constat que les résultats des retours d'expérience scientifiques ne sont pas assez communiqués aux acteurs des territoires concernés. En analysant la saison cyclonique 2017 dans les Petites Antilles, TIREX répond à la fois à...
Article
Full-text available
Guadeloupe is subject to hurricane that generate significant damage. Depending on the local and global economy, cyclones create positive or negative disruptions for island societies and economies. Adaptive forms remain the most numerous at all scales of the territory at the initiative of local authorities, production sectors and inhabitants. The se...
Article
Full-text available
The hurricane season 2017 in the North Atlantic was intense. The events recalled the exposure of the West Indies to these phenomena sometimes devastating, such as the cyclone Irma which caused heavy losses on the French islands of Saint-Martin and Saint-Barthélemy. The post-event phase sometimes gives rise to an experience feedback (RETEX), which r...
Article
Full-text available
L’augmentation du volume des débris, les impératifs de protection de l’environnement, le coût de la collecte et du traitement pour les collectivités territoriales ou les entreprises sont des défis de plus en plus complexes dans les territoires soumis à des catastrophes naturelles, technologiques ou géopolitiques (conflits) destructrices. Le passage...
Article
Full-text available
In the aftermath of a disaster, the debris caused by the destruction of property or vegetation become a crucial problem. The increase in the volume of debris, the growing requirements for environmental protection, the cost of waste collection and treatment for local authorities or companies are increasingly complex challenges for lands subject to n...
Article
Full-text available
This article provides a spatial and comparative approach to evaluate the territorial accessibility in the event of a volcanic crisis in the French West Indies. A spatial assessment of resources and populations exposed to volcanic hazards is performed, followed by an assessment of the risk of territorial isolation due to lahars. Modelling of the ris...
Article
Full-text available
This study aims to better understand coastal processes associated with extreme cyclonic events through the study of the coastal changes, flooding and damage that resulted from the passage of a category 5 hurricane (Irma) on 6 September 2017 over the islands of Saint-Martin and Saint-Barthélemy in the Lesser Antilles. Hurricane Irma was contextualiz...
Article
Full-text available
In the aftermath of a disaster, the debris caused by the destruction of property or the vegetation become a crucial problem. The increase in the volume of debris, the growing requirements for environmental protection and the cost of waste collection and treatment for local authorities or companies are challenges increasingly complex for the territo...
Article
Full-text available
The Caribbean islands constitute a dynamic and old touristic area, but it depends on the international economic context. Different forms of tourism meet the requirements of varied customers and are more or less appropriated by insular actors, allowing local development. The level of development generally leads to a strong appropriation by the popul...
Article
Full-text available
Background Climate change and rising sea level will certainly lead to significant changes in the management of low-lying coastal areas in the coming decades. While the most recent studies in the field of coastal storms-related flooding are increasingly integrated, simultaneously addressing hazards and vulnerability, as well as population risk perce...
Article
Full-text available
Preventing people exposed to natural hazards is a fundamental lever to reduce their vulnerability and the associated risk. In this context, evacuation maps can be considered as a useful tool to educate populations in order to get an appropriate behavior in case of disaster, and to maintain a culture of the risk in exposed areas. Since the catastrop...
Article
Full-text available
Contributions of Geographical Sciences to Tsunami Risk Prevention in Morocco By focusing on Morocco, this article shows how the geographical sciences can contribute to improving the knowledge of tsunami risk and its prevention following an integrated and spatial approach based on the concept of scenario. The main results presented here come from t...
Technical Report
Full-text available
This report focuses on large scale accessibility mapping and evacuation simulations of the ASTARTE test sites. It presents the main results achieved in the Task 9.4 of the WP9. The aim of this task is to provide operatives with scenario-based tools and solutions to develop evacuation plans for local communities. The hazard scenarios were based on t...
Conference Paper
Full-text available
Dans le cadre du programme de recherche CRISSIS, une analyse des perceptions et des représentations sociales sur le risque de submersion marine à Leucate est réalisée. Le projet se concentre sur trois secteurs de la commune particulièrement exposés au risque de submersion marine en raison de leur implantation, entre mer et lagune, sur un cordon lit...
Article
Full-text available
L’accessibilite routiere revet un caractere particulierement strategique pour le maintien des activites economiques, mais egalement pour les interventions de secours. En montagne, les avalanches representent une menace particulierement forte car, outre les victimes et dommages directs qu’elles peuvent causer, elles entrainent tres souvent une perte...
Article
Full-text available
Road accessibility is highly strategic for the maintenance of economic activities but also for the emergency services. In mountains, snow avalanches are a particularly strong threat because, in addition to the victims and direct damage, they cause a loss of accessibility more or less prolonged when the networks are already strongly altered by seaso...
Article
Full-text available
Territorial Accessibility Modeling Serving Tsunami Crisis Management (Mayotte, France) Mayotte, a French territory located in the southeastern Indian Ocean is particularly exposed to natural hazards. Since 2010, the PREPARTOI Program has focused on assessing the tsunami risk in this region and developed original methods to do so. The aim of this ar...
Article
Full-text available
Mayotte, a French territory located in the southeastern Indian Ocean is particularly exposed to natural hazards. Since 2010, the PREPARTOI Program has focused on assessing the tsunami risk in this region and developed original methods to do so. The aim of this article is to bring forward a study of terrestrial accessibility before a tsunami crisis...
Article
Full-text available
This paper seeks to estimate the exposure of the Atlantic coast of Morocco to tsunami risk. A methodological approach and a first set of tsunami risk indicators are presented. The proposed approach is based upon a coupling of tsunami numerical modeling with coastal land use geo-referenced databases. Tsunami numerical modeling is performed for a 175...
Technical Report
Full-text available
Le projet de recherche PREPARTOI propose d’effectuer une étude intégrée du risque de tsunami dans les deux principaux territoires français de l’Océan Indien que sont La Réunion et Mayotte.
Technical Report
Full-text available
Le retour d’expérience mené à la suite du tsunami du 26 décembre 2004 en Indonésie dans le cadre du programme Tsunarisque, nous a permis d’appréhender ce risque sur d’autres territoires exposés. Cette communication développe une approche d’évaluation intégrée du risque de tsunami sur le littoral atlantique Marocain, focalisée sur la ville d’El Jadi...

Network

Cited By

Projects

Project (1)
Project
De la caractérisation des aléas et des risques volcaniques aux outils opérationnels de gestion de crise: le cas des communautés traditionnelles massaï face aux menaces du Ol Doinyo Lengaï (Tanzanie).