Raster processing problem

Question

I am currently doing an assignment using only raster data. Part of that assignment entails finding a potential site for a wildlife park that is accessible by road. I previously did this assignment using only vector data (and did it easily enough using the select by location). I just cannot for the life of me figure out how to do something similar using raster data.

So far I have used the raster calculator OR function in an effort to find roads that intersect park sites - this gave me tiny dots as a result of fragments of roading that intersected park sites (as expected). I did the same thing with buffered and reclassed roads within 100 m of park sites - similar result.

[ATTACH=CONFIG]27946[/ATTACH]

The trouble I am having as that I want to treat the park raster file as separate but complete entities (refer to the image) in that entire park block becomes highlighted if it is within close proximity to roads (and not just small chunks of it).

Sorry if this is quite basic - I think it has gotten to the point where I have been overthinking it!

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Luke_Pinner · Answer

The image software ENVI is one good tool to do it through creating training area and reclassify whole raster image.
The ArcGIS is not a good tool to do it.

How does a supervised classification in ENVI help answer the OP's question? (which is a very simple operation in ArcGIS Spatial Analyst).

TOMKONG · Answer

I am currently doing an assignment using only raster data. Part of that assignment entails finding a potential site for a wildlife park that is accessible by road. I previously did this assignment using only vector data (and did it easily enough using the select by location). I just cannot for the life of me figure out how to do something similar using raster data.

So far I have used the raster calculator OR function in an effort to find roads that intersect park sites - this gave me tiny dots as a result of fragments of roading that intersected park sites (as expected). I did the same thing with buffered and reclassed roads within 100 m of park sites - similar result.

[ATTACH=CONFIG]27946[/ATTACH]

The trouble I am having as that I want to treat the park raster file as separate but complete entities (refer to the image) in that entire park block becomes highlighted if it is within close proximity to roads (and not just small chunks of it).

Sorry if this is quite basic - I think it has gotten to the point where I have been overthinking it!

The image software ENVI is one good tool to do it through creating training area and reclassify whole raster image.
The ArcGIS is not a good tool to do it.

Luke_Pinner · Answer

Have a read of the Raster dataset zones and regions help topic.  Then check out the Zonal Statistics tool which I used to do this:

[ATTACH=CONFIG]28034[/ATTACH]

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