BOOK degli ABSTRACT - Dipartimento di Economia e Sistemi ...

ICFBR 2011International Conference on Fire Behaviour and RiskAlghero, Italy - October 4-6, 2011WUI.1 - Modelling the scattered urbanization process within RUI for forest fire risk control planningMaillé E. 1 , Espinasse B. 21. Mediterranean Ecosystems and Risks Research Group, CEMAGREF, Aix-en-Provence, F-13182, France; 2. InformationSciences and Systems Laboratory (LSIS), Paul Cézanne University, Marseille, Franceeric.maille@cemagref.fr, bernard.espinasse@lsis.orgDiscontinuous urban entities mixed with fuel (forest) areas are key factors of forest fire risk within RUI (Lampin-Maillet,2009). Planning of forest fire risk control requires spatio-temporal information about the future evolution of spatialstructures related to the scattered urbanisation process. This process is complex, driven by interactions between human socioeconomicalsystem and ecosystem dynamics. We propose a simulation model to represent this process using the Multi-AgentsBased Systems (MABS) paradigm. Discontinuous urbanisation process has for original formation mechanism parcelscommercial exchange activity between historical landowners (farmers, forest owners) and buyers whose objective is to build ahouse. These transactions have for first consequence change in land use, and then change in land cover: agricultural or forestuse and cover change for new "urban" use and cover. However, before selling one plot of land, the spatial description of theparcels should be modified in order to better suit to the new use: agricultural or forest parcels are usually far larger then urbanparcels, and have different other spatial characters. In relation to the building regulation, original parcels have to be split,merged, reshaped, etc. before the can be built in. Combination of land use/land cover changes on one hand, and populationand spatial description changes of elementary spatial objects (cadastral parcels, isolated buildings) on the other hand, leads tonew spatial structures and risk changes. An example of a whole process of spatial structure change is shown in the followingfigure.New parcelNew buildingInital parcel(forest)splittingSelling (andchanging landuse)Building-inIn order to represent spatial structure dynamics, two very different kinds of human activities have to be modelled: the first isgeographical elementary objects population and spatial description change activity (including land use/cover change), thesecond is geographical objects economical exchanges activity between human actors. Both activities are linked: for example,parcels are usually split or reshaped with the aim to be able to sell and build-in them in relation with the regulationconditions. Both activities have human decision origin. In order to model human driven spatial structure changes, we specifyan agents-based model called MICROPOLIS. Within MICROPOLIS, two kinds of agents interact: social agents,representing social actors (land owners, buyers, etc.) and geographical agents, representing parcels and buildings. Social agentsnegotiate land commercial exchanges while geographical agents optimise spatial operations under the control (order) of socialagents. Agents behaviours are based on atomic models provided by different disciplines: social agents choices and exchangesare based on generic models from micro-economics (hedonic models), geographical agents operate spatial optimisation usingspatial analysis models, etc. Simulations produce new buildings and new spatial structures in terms of spatial relationshipbetween vulnerable areas and fuel areas, under the constraints of the local regulation policy (land use regulation plan). It isaimed at helping decision makers to choose between different planning options, in order to limit forest fire risk. A researchprototype of the Micropolis model was developed and some tests have been led on Mediterranean periurban local territoriesof Southern East of France.Keywords: land use/land cover change, spatial modelling, agents based modelling, multi-agents based systems, discontinuousurbanisation process, rural urban interface.Entità discontinue urbane mescolate ad aree (forestali) di combustibile sono fattori chiave per il rischio di incendi boschivinelle WUI (Lampin-Maillet, 2009). La pianificazione del controllo del rischio di incendi boschivi richiede informazionispazio-temporali circa l'evoluzione futura delle strutture spaziali relative al processo di urbanizzazione diffusa. Questoprocesso è complesso e guidato dalle interazioni tra il sistema socio-economico umano e le dinamiche degli ecosistemi.Proponiamo un modello di simulazione che rappresenti questo processo, utilizzando il Modello del Sistema Multi-Agente(MABS). Il processo di urbanizzazione discontinuo ha per meccanismo di formazione originale, l'attività di scambio28