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I use ArcGIS 9.3 and the Hawth's tools for Home range analyses. I try to create MCP of marine mammals which all works fine. However, the MCP include some land as well. How can I create a MCP so that it only considers the water area?


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Do you have data that distinguishes between water and land already? I.e., a layer you can use for an erase? That seems like the simplest way to remove the land areas to me. – Baltok Apr 5 '12 at 15:55
thanks for your reply! yes, I do have a shapefile for land and one for the water. how can I do that then? I want to draw the homeranges around the land as well. – user6761 Apr 10 '12 at 12:22

Based on your comment, then the Erase tool should work fine. Just use your water layer as input and your land layer for your erase feature. You do need an ArcInfo license to use Erase.

One easy alternative if you don't have an Arcinfo license is the ET GeoWizards add-on toolbar. The free version allows the use of several tools (including Erase) that would require an ArcInfo license and some tools that don't even come with ArcGIS.

Another option is to download/install QGIS which is free software and use its Difference tool which is just Erase with a different name.

I hope that helps.

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