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I'm on a steep learnig curve here, so aplogies if my question is a one-banana problem.

In ArcGIS 10 I have a contour layer that was generated from an ESR ASCII raster file (batyhmetry of the South Pacific). I also have a point layer (indicating certain seabird breeding locations). For each point I produced 20km buffer zones. So far so good.

What I need to do now, is clip the circular buffer zones so that only the buffer regions between two contour lines remain (in my the case 0m and 150m isolines).

Is there a way in ArcGIS to clip/remove the buffer zones that are outside the 0-150m contours?

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If the purpose of this clipping is to prepare for further analysis, consider returning to the original raster file and carrying out all your operations in raster format. They will be simpler, faster, more accurate, and more amenable to spatial analysis than their vector-formatted versions would be. –  whuber May 29 '12 at 14:37
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2 Answers

up vote 1 down vote accepted

If you have isolines as polyline feature class then I see next steps here:

  1. Select only 0 and 150 m isolines in ArcMap or via ArcToolbox.
  2. Save it into different featureclasses.
  3. Convert each of you isolines (0 and 150 m) into polygons using Feature To Polygon (Data Management).
  4. Cut your 0m polygon with 150m polygon using Erase (Analysis).
  5. You have an area between 0 and 150 m isolines which you can use for clipping your buffer zones.

NOTE1: I assuming that you have enclosed polylines of 0m and 150m isolines and that 150m isolines is situated inside 0m. Otherwise you need to enclose isolines and choose the right order of erasing in step4. Also take a look at FME software - from my experience some of complex data processing tasks can be performed much more quicker and easier than with ArcGIS tools.

NOTE2: Tool Erase (Analysis) needs ArcInfo license.

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Excellent! Thanks heaps, that's exactly what I wanted! –  Tomm May 30 '12 at 3:35
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You don't explicitly say, but if your contours exist as polygons (if not, you'll need to pre-process them to make that the case), then you should be able to use the Select tool to select out the polygons that represent just the 0-150m countours, and use that new feature class (or shapefile) to Clip your circular buffer zones.

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