Intersect tool? Please help ArcGIS novice!

[EmmaGrubb]

Hello,

I am a beginner using ArcGIS so apologies in advance for what is probably (hopefully) a simple question....

I have a set of points, which I have created a buffer around. I have a Land Cover raster map. I want to find out which habitats from the Land Cover Map are within the buffer zone and % coverage within the buffer for each habitat present.

Which tool would do this for me, and how?!

Thanks in advance,
Emma

[MichaelStead]

Probably intersect yep. Intersect gives you only the common area so it is likely what you want.  The percent area can be calculated in an intersect by maintaining a field with the original polygon areas and adding a new area field for the result of the intersect, then just creating a percent from the 2 areas.

If you were interested in more than the percent areas or foresaw further overlays/processing in areas not common to both layers you could union and then you would maintain the residual areas and records.

Either way would work for your purposes. But the intersect doesn't need you to "work" the table much to get your answer

[EmilyJoachim]

Hi Emma,

Did you find a method of automatically calculating the % of habitat classes from land cover maps within a defined buffer zone? I have 1100 sites with a defined buffer zone around each one. I have Land Cover Map 2000 and I am hoping that there is a method of asking Arc GIS 9.3 to do this for me and add the areas to the attribute table for each site. I am a complete novice of GIS!! Thank you in advance!