national institute of geographic and forest …...of public data produced by its partners : e.g....

NATIONAL INSTITUTE OF GEOGRAPHICAND FOREST INFORMATION

F R A N C E

Modellingterritories to better understand

natural risks and risk managementthrough the production of adigital terrain model (DTM)

Designingmonitoring tools

for earthquake zonesand terrain movements

Ensuringquality data distribution

for risk preventionthrough IGN’s geographic

information portal, Géoportail,freely accessible to all

Studyingthe impact of natural disasters

through the interpretationof satellite images

and aerial photographs

Contributingfeedback on risk prevention

through before/afterimpact assessments

Archivingterritorial data

on natural disastersby digitalizing and storing

maps and photographs

14-18 March 2015Sendai, Japan

Supplyingexpertise

for the definitionof risk maps

Identifyingrisks and stakes involved through the production of

authoritative reference databases

A more precise digital terrain model for flood zonesand coastlines. With a precision of 20 to 30 cm, the DTMfor flood zones and coastlines in France is a direct implementationof the European flood map risk management directive.Insofar as coastlines are concerned, the French Navy’s Hydrographicand Oceanographic Department (SHOM) in partnership with IGN,have recently produced a continuous digital model of the coastlinewhere the land meets the sea : ©LITTO 3D. This reference databasewill support public policy decision-making on maritime and coastalissues in the field of natural risk prevention in the case of tsunamis,seawater flooding, cyclonic swells, etc.

IGN provides expert support to create map legends(according to the rules of graphic design) and geographicinformation systems to produce clear, easy-to-read risk maps.

One of IGN’s star products is the Large Scale ReferenceDatabase (©RGE), a structured geographic database, indispensablefor spatial analysis, decision-making and communication in thefield of risk prevention in France. The RGE contains 4 componentsthat can be superimposed and enriched with thematic data:the Topographic Database (© Topo BD), the Address Database(© Adresse BD), the Land Parcel Database (© Parcellaire BD)and the Orthophotographic Database (©Ortho BD).

Geoportail, www.geoportail.gouv.fr,provides access to geographic reference informationwith over 4 million visits per month.In addition to IGN data, Géoportail also contains a vast archiveof public data produced by its partners : e.g. flood maps fromthe 1910 disaster in Paris can be viewed online.

IGN’s Map Archive Collection (Cartothèque)National Aerial Photographic Archive Collection (Photothèque)IGN establishes avalanche risk maps to warn decision-makersof the probable location of avalanches based on data fromeye-witness accounts and archive collections.These maps are used to publicize the existence of potentialareas of risk, where avalanches can (re-)occur.

Data acquisition during flood emergencies.IGN takes its own aerial photographs over the flood zonesat the height of the emergencies and acquires satellite imagesfrom Airbus Defence and Space. These images can be used to assessactual flood areas and evaluate damage incurred.Data acquired during the event can also be superimposed ondata from the Land Parcel Database and the Address Databasefor damage assessment.IGN also contributes to the European emergencymapping program, Copernicus.

Forest damage inventories after stormsAfter major hurricanes, IGN assesses damage to forests by fieldworkand photointerpretation. This data collection leads to forest mapswhich include an estimation of the size of areas affected andthe volumes of wood concerned.Forest firesIGN manages a forest fire database. This homogeneous andreliable data is essential for establishing risk prevention plans,coordinating emergency efforts and developing a EuropeanForest Fire Information System (EFFIS).

IGN has developed a high precision GPS receiver, Geocube,which can detect the smallest movement in the terrain.In single or networked stations, it is used to monitorearthquake zones, landslides on coastal cliffs and glacialmelt in mountainous areas.

www.ign.frwww.geoportail.gouv.fr

Communication Directorbenedicte.dussert@ign.fr

IGN: Natural risk prevention for territorialmanagement in FranceGeographic information, especially in IGN’s geographic and photographicdatabases, provides the elements required for spatial analysis as an aidto decision-making, contributing to a better understanding of the risksand stakes involved, by locating them in time and space.

IGN Conseil / IGN ConsultantsNeil Guion, engineer

neil.guion@ign.fr

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