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Use of very high resolution imagery for control and updating of legal land occupation maps in urban areas

Research project T4/DD/16 (Research action T4)

Persons :

Description :

Objectives :

One of the preoccupations of the sectoral plans is the parsimonious management of territory. This last implies a good local management. Actually, in some regions reserve for additional housing developments can be appear like insufficient and/or can have a negative impact on the land market. In other places, reserves for additional housing developments can look like to generous and simply not justified. Moreover, beside economical social and esthetical preoccupations appear some ecological constraints. Therefor, it is legitimate to update the oldest sectoral plans with an integration of physical and ecological constraints. Sectoral plans have to reflect the present situation and this last is a fundamental information needed for the elaboration of country planning projects.
Classically, needed information is obtained by the combined exploitation of aerial photographs and verification in the field. Up to now, satellite images of means resolution are not able to cope with the requirement of sectoral plan. In fact, this can be explained by the lack of geometrical and spectral resolution of sensor which can not fit the scale needed by author of project.

Methods :

- Unfortunately, digital VHR satellite images (geometric resolution about 1 m for the panchromatic mode) are not yet available for this feasibility study. To surmount this lack of data aerial orthophotoimages of NGI are be used as simulation data.
- First, the study of the conformity between the evolution of landuse and sectoral plan specifications and secondly the disponibility of field for additional housing developments, are be processed by Computer-Assisted Photo-Interpretation (CAPI). Default between legal situation and field situation (landuse) are be mapped directly on the screen.
- The crossing of build-up map with sectoral map allows the estimation of reserve of habitat.

Results:

- Map of the build-up area;
- Map with the comparison between build-area and sectoral specification;
- At the growing level observed during these last years, habit reserve are sufficient until the end of the next century;
- Localisation of build-up areas and estimation of reserve of habitat are given in function of slope and aspect;
- Technical and urbanistic report.