GENIUS: A tool for classifying and modelling evolution of urban typologies

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The work presented in this paper is part of two French national research programs (ACCLIMAT and MUSCADE) that assess the impacts of climate changes and city sprawl until 2100 on the urban areas of Toulouse and Paris. The projects use numerical models to simulate the behaviour of city components (microclimate, energy consumption, etc.) under different scenarios. These models, as most urban modelling tools, use data with high definition levels. However, in the case of a prospective project, the input data are imprecise. In particular, there is a lack of information about buildings footprints, roofs sloping, envelope materials, … In this sense, we developed a new tool to build high definition maps from available data, called GENIUS (GENerator of Interactive Urban blockS). GENIUS creates maps composed of "typical blocks" coming as shape-files of polygons with additional information (height, age, use, insulation…). The "typical blocks" come to seven archetypes of urban blocks that can be found in most European cities. The first task of our method is to transform an existing map into an "archetypical map". To do this, the urban database of the IGN (French Geographical Institute) was used. The maps were divided into cells of 250 meters by 250 meters. For each cell, over 50 morphological indicators were calculated. Seven groups of blocks were identified by means of Principal Component Analysis. The obtained maps will enable us to come up with an accurate simulation of cities energy consumptions and microclimate both present and future. INTRODUCTION During the last years, many research programs have assessed energy-efficient buildings and many models have been developed. However, those tools do not take into account issues related to the urban scale. The scale of urban development requires new paradigms that include urban form, energy use, renewable energy and urban microclimate. Few studies deal with the complexity of energy-efficient cities. Moreover, the temporal scale of urban development and climate change forces urban planners to reconsider the impact of their decisions in a far future (over a hundred years).