Anne Ruas

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Papers by Anne Ruas

Map Generalization

Springer eBooks, 2008

Disdrometer measurements under Sense-City rainfall simulator

The Hydrology, Meteorology and Complexity laboratory of Ecole des Ponts ParisTech (hmco.enpc.fr) ... more The Hydrology, Meteorology and Complexity laboratory of Ecole des Ponts ParisTech (hmco.enpc.fr) and the Sense-City consortium (http://sense-city.ifsttar.fr/) make available a data set of optical disdrometers measurements coming from a campaign that took place in September 2017 under the rainfall simulator of the Sense-City climatic chamber which is located near Paris. Two OTT Parsivel 2 were used. The size and velocity of drops falling through the sampling area of the devices of roughly few tens of cm 2 is computed by disdrometers. This enables to estimate the drop size distribution and further study rainfall micro-physics or kinetic energy for example. Raw data, i.e. basically a matrix containing a number of drops according to classes of size and velocity, along with more aggregated ones such rain rate or drop size distribution with filtering is available.

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Hurricane and waste collection simulations on QGIS for improving post-hurricane waste collection

Abstracts of the ICA, Dec 13, 2021

In the past decades, catastrophic natural disasters such as storms and hurricanes have impacted m... more In the past decades, catastrophic natural disasters such as storms and hurricanes have impacted millions of people around the world: around 33 million of people are affected per year between 2007 and 2016 (Bellow and Wallemacq, 2018). For instance, hurricane Katrina (USA, 2015) caused catastrophic damage from central Florida to Eastern Texas, at least 1836 people died and total property damage was estimated at 125 billion dollars. Furthermore, climate change is likely to increase frequency of most intense categories of hurricanes and is expected to increase sea levels, leading to more destructive storm surges when hurricanes occur (IPCC, 2013). Hurricanes generate large amounts of waste directly related to the induced impacts (Brown et al., 2011). The speed of waste collection and sorting is essential because the waste not only block or slow down human activity but it also generates pollution. The management of this waste is therefore a major issue in post-hurricane crisis management. Hurricane Irma, which hit the Caribbean in early September 2017, in particular the islands of Saint-Martin and Saint-Barthelemy, is a striking example of this problem. In this paper we present an information system to improve the collection of post-hurricane waste in the French West Indies. The first step of our research consisted of analyzing the waste collection process during Hurricane Irma on the island of Saint-Martin. The information collected during several field missions (Beraud et al., 2019) as well as damage data identified from satellite images made it possible to estimate the volume of waste and to understand the collection process (Ruas et al., 2021). In this paper we present the last part of our research which consists in the development of a prototype allowing to simulate the collection of waste from buildings damaged during the passage of a hurricane. In the following we focus on building waste which include construction and demolition debris as well as household goods wastes (furniture, clothes, and wastes of electrical and electronic equipment) as they constitute the largest waste volume. The process was first designed from the data available after the passage of Irma on the island of Saint-Martin. It was then enriched and generalized to be applied to another territory and from a simulated hurricane. The purpose of this tool is to allow communities and stakeholders to test their equipment and resources for waste collection and to imagine other solutions to reduce delays and improve sorting and recycling. The simulation tool will be presented in details in fall 2021 in Guadeloupe to stakeholders (emergency planners or waste managers) to collect opinions and improve functionalities. The process is made up of three steps: the simulation of buildings damage, the calculation of the location of drop-off areas near the damaged buildings and finally the calculation of waste collection from the drop-off areas to waste treatment or storage plants. This process is implemented as a free and open source QGIS plugin (figure 1). The simulation of damaged building Actually, after the passage of hurricanes, remote sensing methods are increasingly used to assess the degree of damage to buildings. This is the case for the passage of Hurricane Irma on the island of Saint Martin where two companies produced two vector databases to identify damaged buildings classified by categories of damage according to the EMS-98 standard. These data give proportion of damaged buildings per category. A post analysis showed that for the island of Saint Martin the damage was strongly related to the building position (Ruas et al, 2021). We use by default this distribution of damaged buildings for other territories but we can also exaggerate or attenuate the proportion of damage buildings. When percentages of damaged building are set, the algorithm chooses buildings randomly until the desired proportion per category is reached. But the case of Saint Martin is special because the island is very small. So it is possible to add a hazard partition map to distinguish the proportion of damaged buildings per area. For example one can use a marine risk submersion map to distinguish the proportion of damaged buildings according to this criteria. Once

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Artificialized land and land take: Drivers, impacts and potential responses

As a major reservoir of biodiversity, soils are essential for many ecosystem services such as foo... more As a major reservoir of biodiversity, soils are essential for many ecosystem services such as food production, climate regulation, flood mitigation, water quality and air quality. Considered as one of the main factors in erosion of the biodiversity, land take describes the global reduction in the proportion of land allocated to farming and forestry or to natural spaces. This work identifies the decisive economic and social factors in land take and its impact on the environment and agriculture. It carries out a summary of the state of knowledge – as complete as possible – of the determinants and impacts related to land take in France and attempts to identify policy tools through a multidisciplinary approach combining life sciences and economic sciences. It highlights the specific problems associated with this phenomenon

Why and How Evaluating Generalised Data ?

Springer eBooks, Feb 27, 2006

This paper presents our proposal to evaluate generalised data from non generalised data. We propo... more This paper presents our proposal to evaluate generalised data from non generalised data. We propose a methodology of evaluation that decomposes the process of evaluation into sub-processes where the user can enter his own specifications and criteria of evaluation. We also propose different levels of synthesis according to the evaluation needs. The evaluation can be an ‘evaluation for editing’ to detect and correct generalisation inconsistencies, a ‘descriptive evaluation’ to describe more precisely how the data set represents the reality, or a ‘evaluation for marking’ to compare different generalisations. Of course working on data evaluation is also very useful to improve generalisation software. The proposed methodology is implemented on Laser-Scan Lamps2 GIS and has been tested on real geo-graphical data base (the IGN-France BDTopo©) to produce maps at medium scale.

Location and estimation of waste volumes following Hurricane Irma in Saint-Martin

Modelling Heterogeneous and Distributed Spatial Datasets to Support Updates Management

The update of distributed geographic data still poses many problems due essentially to the data's... more The update of distributed geographic data still poses many problems due essentially to the data's specific characteristics (spatial constituent, topology, for example). We propose a metadata model to aid in the management of different actors located at several sites handling heterogeneous data that are regularly updated. This model is based on the ISO 19115 standard, which is the metadata standard for geographic information.

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Detecting Building Alignments for Generalisation Purposes

Springer eBooks, 2002

Generalisation is well recognised as a complex process that should trigger specific algorithms, o... more Generalisation is well recognised as a complex process that should trigger specific algorithms, on different types of objects in some logical or appropriate order. To guide the process (where and how to generalise) one solution is to distinguish characterisation from the generalisation process. Characterisation aims at finding and describing relevant 'working areas' that can be a part of an object or a set of objects. As a result, the choice of an appropriate algorithm(s) becomes easier and can be constrained by the detected properties of this new entity. This paper presents a method to both detect and characterise building alignments in an effort to improve the use of generalisation algorithms namely typification and displacement. The first step consists of the identification of building alignments from straight-line templates. The second step characterises these alignments to retain only those that are perceptually regular. The characterisation is based on an analysis of the spatial location of buildings as well as on the properties of the buildings that belong to the alignment in question. To evaluate the regularity of the distribution, estimators are proposed for each property.. At the end a global quality estimator of the perceptual alignment-based on the aggregation of the estimators-is proposed. This global estimator is used to retain the best building alignments that will then be carefully generalised. The results presented have been implemented in the Lamps2 GIS software.

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From sensor data to the perception of phenomena : Software architecture for online access and offline analysis

HAL (Le Centre pour la Communication Scientifique Directe), Aug 26, 2013

In this paper, we present a software architecture that enhances the 3D visualization of sensors' ... more In this paper, we present a software architecture that enhances the 3D visualization of sensors' data. We aim to better explore and analyze sensors' data dealing with atmospheric pollutants. Hence, our software architecture provides two techniques to interact with our geospatial data : a light web application for an easy access and visualization of this data, and a 3D GIS that allows an enhanced analysis of the geospatial data as well as the atmospheric pollutants. In consequence, this work helps at proposing better civil and urban engineering strategies in order to reduce pollution rates, and hence, enhance urban life quality.

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Logiciel de simulation pour améliorer la collecte de déchets post ouragan

Risques urbains =, 2022

Les ouragans constituent un risque naturel important et une menace réelle pour certaines populati... more Les ouragans constituent un risque naturel important et une menace réelle pour certaines populations et certains territoires. Dans ce papier nous présentons les principes et résultats d'un logiciel déposé un open source qui permet de simuler des endommagements en se basant sur des statistiques de l'ouragan Irma et de simuler différents scénarios de collecte de déchets. Après l'analyse de la collecte sur l'île de Saint Martin, nous avons reproduit le processus de collecte en deux étapes, puis nous avons enrichi la méthode pour l'appliquer à des territoires plus grands, disposants de nombreux sites de traitement et de stockage tels que la Guadeloupe ou la Martinique. La méthode proposée permet d'estimer les temps de collecte et la distance parcourue en fonction de la gravité de l'évènement, du nombre et de la localisation des aires de stockage temporaires et des sites de traitement et de stockage mais aussi en fonction des moyens (en camions) et de l'organisation de la collecte en bassins de collecte. Le logiciel peut être utilisé en amont pour optimiser les moyens de collecte ou juste après l'évènement à partir du moment où des zones ou des bâtiments endommagés sont identifiés par télédétection, ce qui est de plus en plus souvent le cas. A noter qu'un des enjeux est non seulement de réduire le temps de collecte, mais si possible de mettre en place des tris, au moins des équipements électriques et électroniques DEEE, pour transformer les déchets en ressources dans un contexte d'optimisation des ressources planétaires et de réduction des trajets. Les enquêtes et expérimentations révèlent également que le temps de chargement-déchargement de déchets est très important ce qui pourrait orienter les choix d'équipements au niveau des collectivités pour accélérer le retour à la normale. ABSTRACT. Hurricanes are a major natural hazard and a real threat to certain populations and territories. In this paper we present the principles and results of an open source software that allows to simulate damage based on statistics from Hurricane Irma (2017) and to simulate different waste collection scenarios. After the analysis of the waste collection on the island of Saint Martin after Irma, we reproduced the collection process in two stages, then we enriched the method to apply it to larger territories, containing more treatment and storage sites such as Guadeloupe or Martinique. The proposed method makes it possible to estimate collection times and the distance traveled according to the severity of the event, the number and location of temporary storage areas and treatment and storage sites, but also according to the means (in trucks) and the organization of waste collection in collection basins. The software can be used before any event, in anticipation, to optimize the means of collection or just after an event from the moment damaged areas or buildings are identified by remote sensing, which is more and more often the case. It should be noted that one of the challenges is not only to reduce collection time, but if possible to set up sorting, at least for electrical and electronic equipment, to transform waste into resources in a context of resource reuse and transport reduction. Surveys and simulation experiments also reveal that the waste loading-unloading time is very important, which could guide the choice of equipment at community level to speed up the return to normal. MOTS-CLÉS. collecte de déchets, simulation, déchets post-catastrophe, ouragans, Caraïbes.

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Map Generalization

Springer eBooks, 2016

Artificialized land and land take

éditions Quae eBooks, May 27, 2020

Implantation d’un modèle conceptuel avec multi-représentation

Le chapitre précédent a proposé plusieurs modèles de données pour décrire des données spatiales o... more Le chapitre précédent a proposé plusieurs modèles de données pour décrire des données spatiales ou spatio-temporelles sous plusieurs représentations. Notamment le modèle MADS [VAN 02] a été défini pour la conception des bases de données spatio-temporelles avec multi-représentation. Il offre une approche générale qui permet au concepteur d'associer à chaque entité, lien ou propriété du monde réel plusieurs descriptions selon le point de vue, la résolution sémantique ou spatiale, ou selon toute autre caractéristique générant des descriptions différentes. Cependant, une fois défini le schéma de la base de données selon ce modèle, la conception de la base de données n'est pas terminée. Il reste alors à implanter ce schéma, qui est de niveau conceptuel, sur un SIG ou SGBD existant. Les modèles de données de ces systèmes sont de niveau logique. Les concepts qu'ils offrent sont moins génériques que ceux d'un modèle conceptuel en général et de MADS en particulier. L'éventail de concepts est plus restreint. Par exemple, le plus souvent pour la dimension temporelle seul le type de données temporel Date est offert, alors que MADS en offre un jeu complet allant des types simples Instant et Intervalle, au type générique Temps qui permet de décrire toute valeur temporelle qu'elle soit un instant, un intervalle ou un ensemble d'instants et/ou d'intervalles. De même, les possibilités de multi-représentation offertes par les systèmes actuels se résument aux possibilités de multi-instanciation des systèmes de type orienté-objets, qui permettent de représenter une même entité du monde réel par des instances de plusieurs classes et sous-classes. Mais aucun système n'offre un mécanisme générique de multi-représentation comme celui de MADS. Enfin, les modèles de données des SIG pour la dimension spatiale sont souvent fortement contraints par les techniques d'implantation interne propres au système. De plus, les SIG n'offrent qu'un jeu limité de concepts spatiaux : soit une vue discrète, soit une vue continue, et si les deux vues sont offertes ce ne sera pas

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Investigating the Effects of Population Growth and Urban Fabric on the Simulation of a 3D City Model

Lecture notes in networks and systems, 2021

Une meilleure connaissance et estimation du risque caniculaire en zone urbaine dense

HAL (Le Centre pour la Communication Scientifique Directe), Jul 1, 2015

-L'îlot de chaleur urbain est étudié à l'échelle de toute une ville, voire de toute une aggloméra... more -L'îlot de chaleur urbain est étudié à l'échelle de toute une ville, voire de toute une agglomération. Depuis quelques années de nombreux travaux visent à améliorer leur précision en incluant la géométrie urbaine, le rôle de la végétation etc. Or, il reste encore à améliorer la description de ces impacts à l'échelle de la rue. Cet article rappelle le modèle d'estimation (TEB), replonge les données calculées dans l'espace géographique pour visualiser les résultats du modèle puis propose une méthode pour désagréger cette information pour enrichir les prévisions à l'échelle de la rue.

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Generalisation of Geographic Information

Publisher Summary Geographers have long understood the relevance of scale to the discernment of p... more Publisher Summary Geographers have long understood the relevance of scale to the discernment of pattern and the derivation of meaning from geographic data. The power of the map lies in its ability to abstract space. It plays a critical role in identifying and interpreting process. Their variety reflects the breadth of application, now made broader by advances in database technology and media. Traditionally the human cartographer was tasked with selecting and symbolizing some abstracted subset of reality. But technological developments in the capture, management, and visualization of geographic information have created a paradigm shift in how we create, utilize, and interact with maps. This technology shift has required us to precisely examine the art and science of cartography and explore innovative ways of modeling cartographic design in the context of geographical information science and interactive techniques. The process of democratization of geographic information raises exciting challenges and opportunities for those working in this field.

Que penser du sens donné à l'artificialisation et à la désartificialisation des sols ?

HAL (Le Centre pour la Communication Scientifique Directe), Sep 22, 2020

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Que penser du sens donné à l’artificialisation et à la désartificialisation des sols ?

De nombreuses études et chiffres sur l’artificialisation des sols En 2015, le CGDD (Commissariat ... more De nombreuses études et chiffres sur l’artificialisation des sols En 2015, le CGDD (Commissariat Général au Développement Durable), après consultation du ministère de l’écologie (MEED à l’époque), de l’agriculture (MAAF), de l’ADEME et du conseil scientifique et du comité d’orientation du programme GESSOL, propose ‘de lancer une évaluation critique de l’ensemble des connaissances scientifiques relatives aux déterminants et conséquences de l’artificialisation des sols ainsi qu’aux leviers d’..

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Methods for improving and updating the knomledge of a generalization system

HAL (Le Centre pour la Communication Scientifique Directe), 2006

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Copyright

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Methods for improving and updating the knowledge of a generalization system

HAL (Le Centre pour la Communication Scientifique Directe), 2006

In this paper we present a method to improve and to update the knowledge used for the automation ... more In this paper we present a method to improve and to update the knowledge used for the automation of the generalization of buildings based on agent paradigm. We propose to store 1/ each building decision, 2/ the reason why the decision was taken (the conflicts) 3/ the result of each algorithm (an improvement or not) and 4/ the successful process chain within all trials. At the end, the processes of all buildings are compared in order to identify the weakness (for example the case where a specific algorithm is often used but never succeeds). When a deficiency is identified we introduce new rules and we study the effect of this change on the efficiency of the process. It can be used either to improve existing knowledge or to introduce new rules associate to the use of a new measure or a new algorithm. The first study has been made on building independent generalization to set the learning methodology. We wish now to apply it on more complex cases such as contextual generalization which still needs knowledge improvement.

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