Step 7: Create kernel density series analysis for all burglary data
Introduction: This part of the module asks students to take their newly address matched
point file and conduct a kernel density analysis for all the data. This is different then the
time series kernel density they will be asked to do later in the module. You will need to
have the Arc GIS 9.2 license extension for Spatial Analyst to complete this part of the
module.
Lesson Procedure: Review Skill Lesson 8: Kernel Density lesson and Density Analysis
powerpoint.
1. Open ArcMap
2. Turn on Spatial Analyst Extension in Tools-Extensions and View-ToolbarsSpatial Analyst
3. Open Spatial Analyst Toolbox-Density
4. Select Kernel Density Tool
5. Input point feature- press folder icon and navigate to Burglary crime file
(geocoded point shapefile) in Geodatabase. (If you have not loaded this into the
geodatabase and then taken that file from geodatabase and added to the Crime
project in Arc Map, do so before this step.)
6. Leave defaults for population, output and area unit fields
7. Once the density file has appeared in the table of contents, examine the results and
answer the following questions:
• What happened? What do you see?
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
• Describe how you moved the layers in the table of contents ( up or down) to see
the results better?
___________________________________________________________________
• Describe any adjusts you made to the density layer properties (symbology
properties: colors/symbols/classification units) to see the results better?
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
• Explore the map by zooming in on the various areas of the study area (Bangor).
Describe the spatial patterns in intensity do you see using this kernel estimation
tool?
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
• Repeat this analysis four more times but change the search radius field to a
number you choose (go up and go down from the default). Mark the output with
the search radius for each time you do this. Also make sure the classification units
(range of data) is the same for every new kernel density. If it is a different range
then you will need to go into the properties for each layer and change it so that all
layers display the same range and colors for classification.
Record the search radii and classification unit range you have chosen for this
analysis.
_1._______________________________________________________________
_2._______________________________________________________________
_3._______________________________________________________________
_4._______________________________________________________________
•
You should finish this portion of the project with 5 density outputs, each using a
different search radius.
Describe how the different search radii changes the overall spatial patterns of
burglaries. If you have to pick one kernel density layer to best represent spatial
patterns of burglaries in this study area, which one would you choose and why?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
Next Steps: Explore other possible factors associated with burglary patterns
such as census variables or geographic features.