Publication sur data.gouv.fr
French Guiana landscape map 2012
This landscape dataset was built using Shuttle Radar Topography Mission (SRTM) data with full resolution (1 arc sec ~ 30m). This map aims at evaluating the geodiversity of natural areas. Twelve landscape types into 5 main categories have been identied with respect to Migon's typology (2006): the coastal plains landscapes (AA. AB. AC); the typical multi-convex landscapes (B. I. J); the multi-concave and joint-valley landscapes (C.D); the more or less dissected plateau (E.F.G) and the all-slopes topography (H). The map was produced at the request of the French Guianan public forest manager of the Office National des Forêts (ONF).
Origine de la donnée :
The landscape map was computed by analyzing the spatial distribution of the different types of landforms. This analysis was conducted in five steps. At first. a manual expert segmentation was performed based on landforms spatial distribution, searching to draw homogenous region based on repeated pattern or dominant type. Secondly, 3 local indices were computed from the landforms map on 1.5 x 1.5 km sliding windows: the Shannon-weaver diversity index, the contagion index, and the majority index (O'Neill et al.. 1988, Mc Garigal et al.. 2002). Thirdly, each boundary of the manual segmentation was compared with maps of the 3 indices for validation. In case of inconsistency, the landscape segmentation was modified in the light of the spatial variability of these indices. Then another Principal Components Analysis was performed with 14 variables computed for each region (average Shannon index. average Contagion index and relative proportions of the 12 different types). A hierarchical…
Objectif : non renseigné