# Site Selection using Spatial Analyst

How can I select a recreation site location based on the criterion that it should AT LEAST be 500 m from a river (shapefile) and AT MOST 15000 m from the same river using Spatial Analyst Extension?

-Umair

• What version of ArcMap are you using? – Paul Jul 3 '13 at 19:39
• I am using 10.1 – beginagain Jul 3 '13 at 19:40
• In most cases that criterion will not identify a unique location. What other criteria are you using and what objective(s) are you trying to optimize? – whuber Jul 3 '13 at 19:44
• You are right. But I have 12 different criteria, if you could please tell me how to apply the mentioned criteria, I'd be able to apply others too to narrow down to most suitable sites. – beginagain Jul 3 '13 at 20:10
• Compare the Euclidean distance grid for the river to 500 and 15000. Done. – whuber Jul 4 '13 at 16:40

As @Whuber stated:

1. use the Euclidean Distance tool on your river data (http://resources.esri.com/help/9.3/ArcGISEngine/java/Gp_ToolRef/spatial_analyst_tools/euclidean_distance.htm).
2. reclassify the output so that distances < 500m = 0, values between 500 and 1500 are 1, and values greater than 1500 are 0. (http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//009z000000sr000000.htm).

Note: this could be tedious depending on what your cell size is. so as an alternative you may want to convert the raster to a shapefile, add a field "suitable" and then use field calculator.

If you have other criteria, do the same thing on each. Then use the raster calculator, add up the values, those with the highest scores are most suitable (assuming all variables are equally weighted in your analysis)

• Thanks for your excellent answer. Could you please explain what syntax should I use for reclassification in raster calculator (if that is what you are referring to)? I only know about Con tool but that can only give 2 values either no data or true raster. – beginagain Jul 5 '13 at 21:57
• you can use the reclassify tool help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//… . Once you have binary maps of suitable (1) and not suitable (0). In the raster calculator just add up the values (e.g. river + criteria2 + criteria3...). – Pat Johnson Jul 6 '13 at 16:43

If you're using a shapefile why not create a multi ring buffer, 0-499m and 500-15000m. Then anything that falls in the outer ring meets your criteria.

• This is a good idea. But I need to use spatial analyst extension. I have, now, created raster layers for every criterion by using euclidean distance tool and will reclassify them. Any idea how could I reclassify (or normalize) on the scale of 0 to 1 instead of 1 to 10? – beginagain Jul 4 '13 at 14:02