Lab 4: Hot Spot Analysis
- What is hot spot
analysis and why is it important?
- Hot spot analysis is a
spatial statistical tool used to determine whether an area with values
displays a statistically significant clustering pattern. Such a pattern
is considered to be statistically significant if the value is surrounded
by other similar values. For example, if a high value is surrounded by
other high values then the output of the hot spot analysis would indicate
a high z-score value. In other words, the values show a significant
clustering of points. This tool is important because it can help policy
makers understand areas where they should focus their attention to. Hot
spot analysis can help us better analyze crimes, voting patterns,
economic geography and other phenomena in a spastically analytic
- In the tutorial, you
used ModelBuilder. Why? How was it helpful?
- This analysis involved
many steps and ModelBuilder helped us understand all the different
geoprocessing components used to run the hotspot analysis. We used
modelbuilder so all the geoprocessing elements could run at once upon
final execution. If any changes had to be made, ModelBuilder made it easy
to redo a step.
- In the beginning of the
exercise, you set some parameters in the “Environments” dialog box. How was this helpful during the rest of
- The environments
dialog helped us apply the same settings for all the components of the
model. The environments set for a particular process will override all
other settings. This will help
ensure the same projection, output value, and location where we save all
- Describe one new
concept or tool you learned about during the exercise.
- One new tool I learned
was the Integrate tool. This tool snaps together nearby incident points
based on a user defined threshold distance. I played around with this
tool and set different threshold distances. I noticed that the higher the
xy tolerance, we noticed more clustered. With lower xy tolerance I
noticed less clustering.
- Answer the following
question from page 10 of the tutorial: What
would your recommendations to the Portland area authorities be, based on
the hot spot analysis exercise?
- I would advise the
Portland area authorizes to set up a emergency service station in the red
colored clustered zone. This area receives the most number of calls. The
areas in blue receive the lowest amount of calls and the areas in cream
receive a medium amount of calls. If more resources are available then
the red and cream colored zones statistically show enough demand to
justify the creation of a new emergency service station.
- What is the purpose of the Generate Spatial Weight Matrix tool?
- This tool is used to create Spatial Weights file and
is particularly helpful when using large datasets. It constructs a
spatial weights matrix (.swm) file to represent the spatial relationships
among features in a dataset.