Selection is one of very important analysis tools in GIS. The selection can be performed by (1) attribute or (2) location. Some analysis like geoprocessing can be performed using selection by location without doing geoprocessing in real which results some temporary files. This simple tutorial gives you some examples how to do selection by location
Case: We are a manager who needs to select compartments resulted from a systematic Repeating Shape tool. The compartments are generated more than what we need. Selction by location then be used to select compartments we need. Some criterias are:
- Select compartments which are overlay with study area
- Select compartments which are completely within the study area.
- Select compartments which are along the boundary of study area.
- Select compartmens which are wihtin < 2000m from river
- Select compartments which are within < 200m from river and > 500m from road
Here are the example situation we have in ArcMap.
To start selection, Clik on SELECTION menu > SELECT BY LOCATION
-
Criteria 1: Select compartments [petak] which are overlay with study area [areal studi]
Do as shown in above image to select compartment [petak] which are overlay with study area [areal studi]
Compartments [petak] which are overlay (even only small part overlay with study area will do) are selected.
-
Select compartments [petak] which are completely within the study area [areal studi]
Do as shown in above image
Only features which are completely within study area will be selected.
-
Select compartments [petak] which are along the boundary of study area [areal studi]
Do as shown in above image
Onyl compartments [petak] which are along the study area boundary will be selected.
-
Select compartmens [petak] which are wihtin < 2000m from river [sungai]
Do as shown in above image
Only compartments which are within 2000 meters from river [sungai] will be selected
-
Select compartments which are within < 200m from river [sungai] and > 500m from road [jalan]
Do step 4 above to select compartments which are within 2000 meters from river [sungai]
Then, do the following selection by location
Do as shown in above image. Do not forget to select ’remove from the currently selected features in’ method
Selected compartments are both within 2000 meters from river [sungai] and more than 500 meters from road [jalan]
If we have successfully select compartments (features) based on our criteria, then we may store the selected features into a new shapefile (or geodatabase). Right-Click on selected layer > Data > Export Data. You can do the rest.
You need to practice a lot in how this function works. There are a lot of choices in selection by location windows.
