Towards Cartographic Portrayal Interoperability – the Revision of OGC Symbology Encoding Standard

International audienceAs Standard Working Group chairs at the Open Geospatial Consortium, this presentation shares our experiences and our results concerning the ongoing revision of the Symbology Encoding standard

Enjeux de la standardisation des représentations cartographiques : Vers une révision de Symbology Encoding

National audienceCette présentation réalisée pour le séminaire transversal du département Aménagement, Mobilité et Environnement (AME) ayant comme thème "Analyse et représentation géographique des données environnementales" expose les limites des standards de cartographie et propose des éléments pour une révision du standard Symbology Encoding

GDMS-R: A mixed SQL to manage raster and vector data

11pInternational audienceTo evaluate urbanization impact on territories, an accurate knowledge of the urban and peri-urban fabrics is unavoidable. To provide advanced characterization of the terrain, modern GIS applications target even wider geographic areas at finer resolutions but they also have to mix data of different types such as Digital Elevation Model (raster layer), buildings (polygonal layer) and roads (polylines layer). Processing both raster and vector data with the same semantic and in an efficient way presents significant challenges to GIS insofar as underlying granularities but also data layout and processing patterns might be absolutely different. We have already focused on the definition and the implementation of an abstraction layer called GDMS (Generic Datasource Management System) to handle and process vector data. Main objectives with GDMS, were to provide the user not only a simple and powerful API but also a spatial SQL derived language. Moreover, as an intermediate layer between the user and the information source, GDMS intends to reduce the coupling between the processes and the specificities of each underlying format. As a consequence, former work may easily be reused in a much larger set of scenarii. The learning curve is consequently even simpler. In this paper, we propose a raster extension to the GDMS layer called GDMS-R. Even if, there is currently no OGC standard concerning raster processing (using well-known SQL language), there already exists a de facto standard called Map Algebra defined by C. D. Tomlin in 1990 and commonly implemented in a wide set of GIS. Our objective is a bit different insofar as we propose to extend SQL language. We present the integration of Map Algebra concepts in GDMS through the GRAP (GeoRAster Processing) language. As for GDMS, reuse is enhanced by the possibility of being vendor-independent (middle-ware approach) and the extension capabilities of the underlying SQL language. To demonstrate the capabilities of GDMS-R, we present a use case relative to the deep impact of increased urbanization on the vulnerability of peri-urban hydro-systems: impact of the linear constraints on the runoff water pathways and accumulation that uses both vector and raster data in an unified way

GDMS: An abstraction layer to enhance Spatial Data Infrastructures usability

15pInternational audienceThe practical exploitation of SDI (Spatial Data Infrastructures) raises number of issues as far as it grows. Among them is the heterogeneity of data sources and thus the difficulty for GIS users not to depend on the data source format and of course to learn different systems. This a major flaw with respect to reuse and data sharing. The purpose of our work is to propose a new semantic layer derived from the SQL language that is independent of the underlying data source. This layer, called GDMS (Generic Data source Management System) can first be seen as an abstraction layer between data sources and the SDI tools. We will also show how this layer extends both SQL and spatial semantics and improves the exploitation of the SDI, by providing feedback both in terms of work and data reuse. A simple example mixing heterogeneous data sources will be presented

H2GIS a spatial database to feed urban climate issues

International audienceTo understand the urban climate, predict the effect of urbanization or attend to improve the impact of some human activities, it is necessary to have a good understanding of the role of the urban surface. Indeed it has been demonstrated that surface forms affect urban microclimate (Givoni 1989, Oke 1981, 1988) and therefore changes the consumer behaviour of residents especially the building energy consumption (Santamouris, 2001, Ohashi et al., 2007).The urban territory is continuously changing: high-rise buildings densification, new road infrastructures, increase of impervious surfaces, consumption of agricultural and natural areas… The result is new border, new shapes and new morphology for the urban geometries. In this context, monitoring urban changes became a challenge for urban planners and decision makers.Geographical Information System (GIS) applications are increasingly being used to compute a set of indicators such as the Sky View Factor, the mean building height, the compactness ratio… All of theses indicators are used to study and monitor the urban structure (Long et al 2003, Bocher et al 2009). Besides, in the late 1990s, a large number of GIS-based tools have been developed by taking advantage of data organisation, spatial analysis and visualisation (eg. cartography). These three functions coincide with the focus of an indicator that needs to organize data, to quantify and to communicate.If this diversity is valuable, on the other hand it can also act as a disincentive for the scientists and urban stakeholders communities. These tools are often build to answer a particular subject (mono-thematic approach). Moreover, most of them are based on proprietary softwares which limits their distribution, the possibility to examine their implementation (algorithm) since the main software is required to run the tool (black box) (Steiniger and Bocher, 2009, Steiniger and Hay, 2009). Last but not least, the definitions used to compute an indicator may differ according to the authors.This situation is in sharp contrast with the needs of the scientific community to share results and experiences, and to experiment with new methods. Moreover, it is inconsistent with number of laws and regulations relating to the protection of the environment that promote common indicators.To fill this gap, we propose a new open source spatial database, called H2GIS (http://www.h2gis.org/), to manipulate and process geographic and alphanumeric data (Gouge et al, 2014). H2GIS is a spatial extension of the Relational Database Management System (RDBMS) H2 Database Engine (http://www.h2database.com/) in the spirit of PostGIS (http://postgis.net/). It adds support for managing spatial features and operations on thenew Geometry type of H2. H2GIS is fully compliant with the OGC’s Simple Features for SQL (SFSQL) 1.2.1 standards (Herring 2010, 2011).In this paper we show how the spatial RDBMS H2GIS should be an ideal framework to model the urban data (store and distinguish spatial relationships), create a generic set of spatial urban indicators and used them with massive data (scalable, multi-core processing).As an illustration, H2GIS is used in the MApUCE project which aims to integrate in urban policies and most relevant legal documents quantitative data from urban microclimate, climate and energy. Based on literature review, we offer an open spatial analysis toolbox to study the urban surface

Noise mapping based on participative measurements

The high temporal and spatial granularities recommended by the European regulation for the purpose of environmental noise mapping leads to consider new alternatives to simulations for reaching such information. While more and more European cities deploy urban environmental observatories, the ceaseless rising number of citizens equipped with both a geographical positioning system and environmental sensors through their smartphones legitimates the design of outsourced systems that promote citizen participatory sensing. In this context, the OnoM@p system aims at offering a framework for capitalizing on crowd noise data recorded by inexperienced individuals by means of an especially designed mobile phone application. The system fully rests upon open source tools and interoperability standards defined by the Open Geospatial Consortium. Moreover, the implementation of the Spatial Data Infrastructure principle enables to break up as services the various business modules for acquiring, analysing and mapping sound levels. The proposed architecture rests on outsourced processes able to filter outlier sensors and untrustworthy data, to cross- reference geolocalised noise measurements with both geographical and statistical data in order to provide higher level indicators, and to map the collected and processed data based on web services

Evaluation des sources de polluants susceptibles d'impacter les ouvrages de gestion des eaux pluviales – Diagnostic exhaustif à l'échelle du territoire nantais

International audienceTo offset the effects of soil sealing and to deal with stormwater management issue s , cities have adopted BMPs (Best Management Practices) for twenty years . Many facilities exist on urban areas and h ave proved to be efficient on a hydrological point of view, but questions remain about pollutants. Under the Matriochkas project, w h ich focuses on performances of stormwater management facilities in terms of retention of pollutants, an inventory on retention and infiltration basins and swales is conducted throughout the Nantes metropole territory. An exhaustive diagnosis of sources of pollutants is carried out on the facilities identifi ed in this inventory, using a methodology based on spatial analysis of geographic data. More specifically, contributive area of facilities is identified by an automatic method based on drainage networks. The description of these contributive areas in terms of geographic data (land use, human activities such as road traffic , and practices ), and literature data on emissions of pollutants in urban areas, makes it possible to estimate potential pollutant loads which discharge into these facilities.Afin de compenser les effets de l'imperméabilisation des sols et pour répondre à la problématique de gestion des eaux pluviales, les collectivités se tournent depuis une vingtaine d'années vers les techniques alternatives. De nombreux ouvrages existent sur les territoires urbains, et si leurs performances hydrologiques sont connues, leur rôle vis-à-vis de la rétention des polluants l'est moins. Dans le cadre du projet Matriochkas, qui s'intéresse aux performances des ouvrages de gestion à la source vis-à-vis de la rétention des polluants, un recensement des bassins de rétention et d'infiltration ainsi que des noues est mené sur l'ensemble de l'agglomération nantaise. Un diagnostic exhaustif des sources de pollution est réalisé sur les ouvrages identifiés dans ce recensement, en utilisant une méthodologie basée sur l'exploitation de données géographiques. Cette méthodologie consiste à déterminer la zone contributive des ouvrages en développant une méthode automatique qui s'appuie sur les réseaux de drainage. La description de ces zones contributives à partir de données géographiques (occupation du sol, activités anthropiques dont le trafic routier, et usages) et de données de la littérature relatives aux émissions de polluants sur les surfaces urbaines, permet d'estimer a priori les flux de polluants déversés dans ces ouvrages

Crowdsourcing of Noise Map Pollution using Smartphones: Journées des Laboratoires SIG de Suisse romande

We present at the LSSR journey, the ENERGIC-OD project and the application developed by the LAB-STICC (CNRS) and LEA (IFSTTAR) laboratories to collect noise data from smartphones.We present the ENERGIC-OD project and the application developed by the LAB-STICC (CNRS) and LEA (IFSTTAR) laboratories to collect noise data from smartphones

Urban Climate, Human behavior & Energy consumption: from LCZ mapping to simulation and urban planning (the MapUCE project)

International audienceThe MApUCE project aims to integrate in urban policies and most relevant legal documents quantitative data from urban microclimate, climate and energy.The primary objective of this project is to obtain climate and energy quantitative data from numerical simulations, focusing on urban microclimate and building energy consumption in the residential and service sectors, which represents in France 41% of the final energy consumption. Both aspects are coupled as building energy consumption is highly meteorologically dependent (e.g. domestic heating, air-conditioning) and heat waste impact the Urban Heat Island. We propose to develop, using national databases, a generic and automated method for generating Local Climate Zones (LCZ) for all cities in France, including the urban architectural, geographical and sociological parameters necessary for energy and microclimate simulations.As will be presented, previous projects on adaptation of cities to climate change have shown that human behavior is a very potent level to address energy consumption reduction, as much as urban forms or architectural technologies. Therefore, in order to further refine the coupled urban climate and energy consumption calculations, we will develop within TEB (and its Building Energy Module) a model of energy consumer behavior.The second objective of the project is to propose a methodology to integrate quantitative data in urban policies. Lawyers analyze the potential levers in legal and planning documents. A few “best cases” are also studied, in order to evaluate their performances. Finally, based on urban planning agencies requirements, we will define vectors to include quantified energy-climate data to legal urban planning documents. These vectors have to be understandable by urban planners and contain the relevant information.To meet these challenges, the project is organized around strongly interdisciplinary partners in the following fields: law, urban climate, building energetics, architecture, sociology, geography and meteorology, as well as the national federation of urban planning agencies.In terms of results, the cross-analysis of input urban parameters and urban micro-climate-energy simulated data will be available on-line as standardized maps for each of the studied cities. The urban parameter production tool as well as the models will be available as open-source. LCZ and associated urban (and social!) indicators may be integrated within the WUDAPT database

RÔLE DE L'OCCUPATION DU SOL VIS À VIS DE LA MODÉLISATION DES FLUX ENERGÉTIQUES ET HYDRIQUES EN MILIEU URBAIN ET PÉRIURBAIN

National audienceLe projet Rosenhy vise à étudier l’impact de l’occupation du sol sur la modélisation météorologique et hydrologique en termes de flux énergétiques et hydriques, en milieu urbain et périurbain. Trois sites appartenant aux observatoires français OTHU et ONEVU sont au centre de ce projet. Le quartier urbain hétérogène du Pin sec (Nantes), imperméabilisé à environ 45%, a fait l’objet d’une campagne expérimentale durant le mois de juin 2012, visant à estimer les flux de chaleur sensible et latente avec une haute résolution spatiale et temporelle par rapport aux mesures réalisées en continu sur ce site depuis 5 ans. Deux bassins versant périurbains (La Chézine à Nantes et l’Yzeron à Lyon), avec un taux d’imperméabilisation moins important (environ 10%) mais grandissant depuis plusieurs décennies, sont aussi étudiés. Ces deux derniers sites bénéficient d’un suivi hydrométéorologique depuis 10 ans pour la Chézine et 15 ans pour l’Yzeron. Sur ces trois sites, différentes sources de données d’occupation du sol à différentes résolutions sont disponibles :différentes bases de données géographiques communément utilisées par la communauté scientifique et les collectivités et des données télédétectées (multispectrales et hyperspectrales). L’utilisation de ces données en entrée de différents modèles météorologiques et hydrologiques implique un travail d’analyse et de classification pour adapter les informations aux besoins des modèles. Dans ce projet, les différents modèles adaptés au milieu urbain ou périrubain sont évalués et améliorés. Ainsi, les modèles hydrologiques périrubains sont en développement pour prendre en compte les différentes pratiques de gestion des eaux pluviales existantes (noues, toitures végétalisées, ...). L’utilisation conjointe des données simulées par les différents modèles aidera à déterminer le rôle de la part des surfaces naturelles et artificielles sur les bilans énergétique et hydrique en milieu plus ou moins urbanisé. Le milieu périurbain étant en évolution, le projet s’intéressera aussi à des scénarios d’urbanisation prospectifs en regardant d’une part l’impact de la densification sur les scénarios construits pour l’Yzeron lors du projet AVuPUR (ANR-VMCS, 2008-2011) et d’autre part, en réfléchissant conjointement avec Nantes Métropole, aux possibles voies d’évolution sur le bassin de la Chézine