1.1.1. Indices Of Arrangement
It would be illusory and quite tedious to propose an exhaustive list of indices of spatial arrangement suggested in the literature. The most productive fields of research in this respect are certainly those of the geography, ecology, regional sciences and the numerical image processing. From the methodological point of view, most significant is to seize the aspects of the spatial arrangement which one wishes to describe through indices, the way of interpreting them, as well as their context of use.
The context of application of the indices of arrangement is influenced by the following factors:
- The nature of spatial features:
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- For point and linear objects distributed in the study area, one will describe their spatial arrangement by a measurement of density per quadrat. We will not approach this situation within the framework of this Unit.
- For contiguous zonal objects proposing a spatial division of the study area. It is on this type of context that we will pay our attention in this Unit.
- Mode of description of the spatial distribution:
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- Our major interest is certainly the description of the arrangement of spatial objects. In object mode the units of observation fully correspond to the spatial objects.
- In image mode, the spatial objects correspond to the "zonal regions" produced by the aggregation of the units of observation, the contiguous cells sharing the same property. But it is also possible to be interested in the spatial arrangement at the level of the neighborhood of each cell.
- The scale of description of the spatial arrangement:
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- At the scale of the whole of the study area, one will account for the "structure" of the spatial arrangement, either globally for all the objects, or specifically by category or class of properties of these objects.
On the level of the spatial objects | On the level of a group of objects with a common thematic property | On the level of the study area |
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12 spatial objects | 4 objects with a class of average aptitude for agriculture | Distribution of the thematic properties of the 12 objects |
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