This week’s module focused on making locations decisions
based on using basemap layers, Euclidean Distance analysis, Reclassifying Data,
Weighted Overlays, attribute table field calculator, Page layouts and model
builder. Since multiple data frames were
needed for each map, it was important to create some base map layers and to be
sure that when adding data frames the correct coordinate system was
chosen. With this lab we continued to
practice reviewing our metadata and the appropriately organizing both provided
data and created data New this week was the use of Euclidean (as the crow
flies) Distance analysis, raster data reclassification and weighted
overlays. Blending these tools gave us
the ability to make location decisions based on criteria provided by a
client. Creating a model for the
weighted overlay portion allowed us to save time as we could simply tweak our
parameters rather than starting from scratch with each raster each time. Because of the various steps involved in this
week’s map production, I felt it useful to outline my steps. Below you will find my outline and the two resulting
maps.
Organize and Document
WorkA.
Examine the Data
1.
The data has
already been downloaded and clipped to Alachua County
2.
It is all in GCS
NorthAmerica 1983 Projection NAD 1983 UTM Zone 17N, Meter
3.
See separate
table within this document containing Metadata information.
B.
Organize and
Document your Work
1.
Make a new folder
in Lab08_Location Analysis named Results.
2.
Within the
results folder create a new geodatabase named results. This is where analysis results (data files) will be saved.
3.
Open ArcMap and
save document as Location1_rh
4.
From File Menu,
choose Map Document Properties
a)
Add a title,
author and descriptive text
b)
Set default
geotabase to results.gdb
c)
Always check box
“Store relative pathnames to data sources”
C.
Set the
Environments
1.
View Menu/Data
Frame Properties/Coordinate System tab/Projected Coordinate
Systems/UTM/NAD193/Zone 17N
2.
Geoprovessing menu/Environments/expand
workspace, output coordinates and processing extent
a)
Current
workspace: Data\Location.gdb
b)
Scratch
workspace: Results\results.gdb
c)
Output
Coords: Same as Display
d)
Processing
Extent: choose Location.gdb and select cns_tracts
e)
Raster Analysis
settings: limit to cns_tracts by using a mask
(1)
Cell size “as
Specified Below”, 300
(2)
Mask: Cns_tracts
3.
Select OK and
save map
D.
Conduct Analysis
1.
Add cns_tracts,
county, publands, places and roads from arc catalog
2.
Symbolize layers;
right click data frame and select New Basemap Layer and drag all layers under
this group layer
3.
Right click on
Basemap layer and select Analyze Basemap Layer
a)
Review error
report to identify potential drawing performance issues and how to address
them.
4.
Using the effects
toolbar, adjust the Dim Level
a)
If at a later
time you need to make data edits or layer updates, drag the map layer out of
the basemap, edit it and then return it to the basemap layer group.
E.
Calculate
Distance from North Florida Regional Medical Center
1.
Insert a new data
frame named Hospital Distance
a)
Set the
coordinate system in the data frame properties
2.
Create a
selection to select North Florida Regional medical Center
3.
Export as NFRMC
to results.gdb, use same coordinate system as data frame and make sure to export
as feature clas.
4.
Remove the
original hospitals layer
5.
Symbolize and
label the NFRMC.
a)
Add field Abbrev
to attribute table, text
b)
Use field
calculator, string, “NFRMC”
c)
Use this field as
the label field
6.
Spatial Analyst
Tool/Distance/Euclidean Distance
a)
Input: NFRMC
b)
Output raster:
dist_hosp_rh in results.gdb
c)
Cell size: 300
7.
Use the
reclassify tool to edit proximity zones to whole number values and 9 defined
intervals.
a)
Spatial
analyst/reclass/reclassify
b)
Input rater:
dist_hosp
c)
Reclass field:
Value
d)
Output raster:
results.gdb\reclass_hosp_rh
8.
Classify, Defined
Interval, interval size 5000
9.
Click Reverse New
Values to flip the value order so that 9 is the most favorable and 1 is the
least favorable.
10.
Remove the
dist_hosp_rh once the reclass_hosp_rh is complete.
11.
Select an
appropriate color scheme for reclass_hosp_rh
12.
Make the
cns_tracts hollow and save the map
F.
Calculate
Distance from UF (University of Florida) CHOMP CHOMP
1.
Insert new data
frame named College Distance and set the coordinate system in the data frame
properties
2.
Add cns_tracts
and schools
3.
Isolate UF from
the schools layer and export as a feature class. Label and symbolize appropriately and then
remove the schools layer. UF_rh in Results.gdb
4.
Perform Euclidean
Distance Analysis for UF. Export as
dist_uf_rh
5.
Reclassify the
output
a)
Defined interval
5000 which will generate 8 values
b)
Reverse new
values so that 8 equates to the most favorable location closest to UF and 1 the
least favorable.
c)
Name the output
reclass_UF_rh
d)
Remove dist_UF
upon completion
6.
Choose an appropriate
colorscheme for reclass_UF_rh and save the map.
G.
Calculate
Percentage of Population Aged 40-49
1.
Insert a new data
frame named 40-49 and set the coordinate system in the data frame properties
2.
Add cns_tracts
3.
Open the
cns-tracts attribute table and click options/add field
a)
Name: perc_pop
b)
Field type: float
c)
Click ok
4.
Right click the
new perc_pop field and select Field Calculator.
Click yes to edit outside of a session.
Perform the following calculation:
a)
[AGE_40_49]/[POP2010]*100
click ok
5.
Display cns_tracts
by Quantities, Graduated colors, Value: perc_pop and save yor map.
H.
Convert Tracts to
a Raster for Age Range and reclassify
1.
Conversion
tools/To Raster/Feature to Raster
a)
Input cns_tracts
b)
Field: perc_pop
c)
Output raster:
results.gdb\IdealAge_rh
2.
Once IdealAge
loads, turn off cns_tracts
3.
Reclassify as
whole number values. Use the default of
9 classes, reclass_age_rh
4.
Once
reclass_Age_rh loads, remove IdealAte
5.
Select
appropriate color scheme for reclass_Age_rh
6.
Turn on
cns_tracts and make hollow
7.
Add Uf and NFRMC,
symbolize and layer each feature. Save
your map
I.
Calculate
Percentage of Population of Homeowners
1.
Insert a new data
frame called Percent Homeowners, set coordinate system
2.
Add Census Tracts
3.
Add a new field
called perc_own use the field calculator to generate percent homeowners
(owners/(owners+renters))*100
4.
Convert
cns_tracts Feature to Raster based on perc_own field; output = Perc_Own_rh
5.
Reclassify the
outut, 9 natural break classes where nine is the most suitable class/value.
Reclass_Own_rh
6.
Symbolize and
display cns_tracts as hollow
7.
Add UF and NFRMC,
symbolize and label.
J.
Creating Weighted
Overlays
1.
Save Location1_rh
as Location2_rh
2.
Insert new data
frame named Weighted Analysis and set coordinate system.
3.
Add
reclass_hosp_rh, reclass_Uf_rh, reclass_age_rh and reclass_own_rh
a)
Symbolize
appropriately
b)
Remove all other
data frames except for basemap data frame which will be used as an inset.
4.
ArcCatalog/results.gdb,
New Toolbox named Weight_Analysis
5.
Right click
Weight_Analysis toolbox and create new model
a)
From the TOC add
the four “reclass” rasters into the model
(1)
Use the auto
layout and full extent icons to focus your model
b)
Drag the Spatial
Analyst/Weighted Overlay tool into the model
c)
Use the connect
tool to connect the rasters to the Tool; choose “weighted overlay table from
the pop up menu
d)
Double click the
Weighted Overlay tool to open
e)
Confirm the scale
values match the fields in your map
f)
Choose set equal
influence so that each % influence equals 25%
g)
Run the model and
save as weight1_rh in the results.gdb
(1)
Model errored out
within ArcDesktop but ran perfectly via ArcCatalog
6.
Create a second
weighted overlay
a)
Follow the steps
above, but this time adjust scale values so that the primary focus becomes
proximity to the workplace.
b)
You will want to
restrict a portion of the age and ownership values (lower end of the criteria)
so that the weighted analysis shifts to workplace proximity.
K.
Compile and
Present Results
1.
Make sure to
appropriately symbolize both weighted analyses
2.
Add places and
label the ones closest to suggested areas
3.
Be sure to turn
on the cns_tracts, but make them hollow
4.
Add NFRMC and UWF
and symbolize/label appropriately
5.
Choose three
census tracts from each weighted overlay
a)
Symbolize and
label appropriately
b)
These are the
focus of the map and should be easy to interpret
6.
Make sure to
summarize your findings and explain your weighting process so that your clients
not only understand the values but also feel confident in your suggestions
a)
I restricted the
lowest 4 values for proximity to NFRMC and UF and weighed each of these at 40%
b)
I did not
restrict values for the ownership or age category, but weighted them at 10%.
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