LAB4_GEOG5181C6081C_AU23
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Date
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Prof. Kim
Geography 5181C/6081C: Lab Assignment 4
Understanding ModelBuilder & Generating Spatial Features
Assigned Date:
Monday, October 30, 2023
Due Date:
Sunday, November 5, 2023, Labs are marked down 10% for each
24 hours late.
Goals:
The first three parts of this lab are to learn [1] how to use
ModelBuilder to make a blueprint of your analysis, [2] how to create
repetitive spatial analysis using ModelBuilder, and [3] how to utilize
ModelBuilder in decision-making situations. The last part of this lab is to
create spatial features based on raw coordinates.
Notes:
1.
Any ArcGIS Pro documents opened and manipulated for the exercises,
as well as other necessary data, should be saved in your student folder.
2.
To understand ModelBuilder, please read over
Chapter
in GETTING TO
KNOW ArcGIS.
Must:
1.
Know how to look for different GIS functions in Toolbox (Help/Search).
2.
Know how to project files.
3.
Use critical thinking to answer some of the questions.
Attention: For this lab, you don’t need to zip and
upload the data
and results of the part I (as the file size is quite large), but you do
need to zip and
upload the data and results of part II and part III to
the blackboard.
PART I. Exploratory Spatial Data Analysis (ESDA)
Although many functions such as catalog and display of geographic data are
very useful, the true power of GIS lies in its capabilities for spatial analysis.
Step 1
:
Examine the datasets (under data\part1 folder).
The first file is a polygon shapefile of owned parcels in
Hamilton County
with
an attribute for
PARCELID
, and the second is a point of sold parcels with
appraisal values and sales values in the same area. In Catalog panel you
should now see two spatial datasets: parcel_sale, parcel_poly.
Drag “parcel_sale” and “parcel_poly” into ArcGIS Pro.
Right click “
parcel_sale
” -> Open Attribute Table -> Right click on the
“
FINVALTOT
” column -> statistics.
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Prof. Kim
Q1.
How many points are there? What is the maximum value? What is the
mean value? What is the sum value of all the parcels in this dataset?
(40
points)
Q2.
Do the exact same thing for “SALEPRICE”. What is the maximum value?
What is the mean value? What is the sum value of all the parcels in this
dataset?
(30 points)
Selection menu -> Select By Attributes. With the Select By Attributes
window open, separately query for (1)
FINVALTOT
> 250000; (2)
FINVALTOT
> 1000000; (3)
FINVALTOT
> 2000000; and (4)
FINVALTOT
>
10000000. Make sure these are individual queries rather than cumulative
ones.
Q3.
How many parcels for sale that are in East of I71 are valued over
$1,000,000? Are there any parcels for sale over $1,000,000 that are in West
of I75? How many parcels are valued over $10,000,000 in the entire region
(Hamilton County)?
(30 points)
Q4.
Does there appear to be a relationship between FINVALTOT and ANY
VARIABLE? Where are most of the clusters of expensive parcels?
(20 points)
Step
2
:
Create Subsets.
Join the parcel_sale to parcel_poly according to the common field
“PARCELID”
Right click parcel_poly -> Data -> Export features. Save the output in
yourdatafolder and name the output feature class as parcel_sale_p.shp.
This might take several minutes.
Customize menu -> Extension -> Check the box of Geostatistical Analyst
Customize menu -> Analysis -> Tools -> Toolboxes -> Geostatistical
Analyst
Geostatistical Analyst -> Utilities -> Subset Features
Input features:
parcel_sale_p
polygon
Output training feature class: yourdatafolder\parcel_ha_2
Output test feature class: yourdatafolder\parcel_ha_98
Size of training feature subset: 2
Subset size units: PERCENTAGE_OF_INPUT
Click OK and ArcGIS will randomly subset the polygon. This could take a
while so be patient. The new datasets will be added to the layout
automatically.
Q5.
Why did you subset the feature instead of using the whole thing? What
is the purpose of a “training” set and a “testing” set? Why is random
sampling so important?
(30 points)
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Prof. Kim
In ArcMap, there is a trend analysis which could be used to analyze
the subset. It is not available in ArcGIS Pro, but I would give you the
steps in ArcMap. If you are interested in it, you can try.
Analyze the Subset.
Geostatistical Analyst -> Explore Data -> Trend Analysis
Handling Coincidental Samples -> “Include all” -> click “OK”.
At the bottom of the Trend Analysis window, Layer -> parcel_ha_2,
Attribute ->FINVALTOT.
Graph Options -> uncheck Sticks and Input Data Points.
Uncheck the Legend (upper right) as it is unnecessary.
The 3D graph can also be rotated using the wheels along the lower right
corner of the graph window.
Zoom in to see the details:
The brown points on the floor of the graph represent the spatial
distribution of the “
parcel_ha_2
” samples.
The green and blue points on the walls are the values of the samples.
Both the green and blue points are the same values – they are simply
shown in either their east-west distribution (green) or north-south
distribution (blue).
Each wall is a trend line (similarly green or blue) showing the average
trend in the values as one moves along the direction of the
distribution.
Click the
Add to Layout
button and it will be imbedded in your ArcMap
layout.
Q.
Are real estate values higher next to the county boundary, or north, west,
south, or east? Do real estate values increase or decrease towards the
Northeast? Do you think this trend analysis is accurate? What could be some
sources of error? How would you improve the reliability of this analysis?
Map 1.
Create a map showing your
parcel_ha_2
. Label on the map how
many polygons were sampled and the mean, min, and max values. Your map
should be projected in
NAD_1983_StatePlane_Ohio_South_FIPS_3402_Feet
.
(50 points)
Map 2.
Produce a map showing the
parcel_ha_2
overlay with topography
data. Your map should be projected in
NAD_1983_StatePlane_Ohio_South_FIPS_3402_Feet
.
(50 points)
Tips
:
To overlay the topography data, go to Toolbox -> Spatial Analyst Tools
-> Surface -> Hillshade, Input Raster -> DEM, Output Raster ->
youdatafolder\hillshade.
Use this hillshade dataset as your topography data to make the map.
(Remember to check the extension of Spatial Analyst before using
the tools)
For the Part I, you need to turn in the followings:
Map 1 and 2 (100 points)
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Prof. Kim
Answers to Question 1 through 5 (150 points)
PART II. ModelBuilder
ModelBuilder is a graphic design tool for diagramming solutions to spatial
analysis problems. The workflow diagrams are called models (Note that
model here is different from scientific model in general). A GIS analysis
model is a sequence of steps or functions used as part of a GIS analysis.
These sequences of geoprocessing steps can also be represented in ArcGIS
with ModelBuilder. The user can repeat the same procedure over and over if
necessary. ModelBuilder offers 3 main benefits: 1) It records all of the steps
involved in a procedure; 2) It allows the procedures to be easily repeated and
shared with others; and 3) It provides a visual representation to help with
understanding what is going on in the procedure.
Step
1
:
Predictive model with ModelBuilder
In this part, you will use ModelBuilder for exploratory analysis designed to
aid in the creation of a predictive model for Mayan archaeological sites. In
the context of archaeology, a predictive model is “a tool that indicates the
probabilities of encountering an archaeological site anywhere within a
landscape“ (from Minnesota Archaeological Predictive Model). Developing a
predictive model essentially consists of trying to determine the logic and
preferences in site selection of the people who built the archaeological sites
in question. Using GIS, one can examine a set of environmental factors to
see if any of their possible combinations seem to be repeatedly associated
with a type of archaeological site. These insights can then be used to predict
where other sites are likely to exist on the landscape. To illustrate, imagine
you want to find new archaeological sites with artifacts from the Chumash
tribes. Say that through exploratory analysis of previously-known sites you
discover that they seemed to prefer occupying locations that are near the
ocean and close to glades where with sage tends to grow. You could then
analyze a region to see which areas in it meet those criteria, and direct your
field searches to them in order to increase the likelihood that your
archaeological dig will in fact find something. Before moving on to the
ModelBuilder procedures, we must first prepare some of the data sets to be
used.
In ArcGIS Pro, add all the data in “
Maya
” geodatabase under …\data\part2
folder to your map.
Highlight “
arch_sites
” in the Contents.
Customize menu -> Analysis -> Tools -> Geostatistical Analyst
Geostatistical Analyst -> Utilities ->Subset Features
Input features:
arch_sites
Output training feature class: …\Maya.gdb\arch_sites_14
Output test feature class: …\Maya.gdb\arch_sites_86
Size of training feature subset: 14
Subset size units: PERCENTAGE_OF_INPUT
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Prof. Kim
Click Run.
Step 2
:
Save in Geodatabase
In the Contents, only check and display “
county_bnd
” layer.
Right click “
county_bnd
” -> Open Attribute Table.
Select the record that COUNTRY field is “
GUATEMAL
”.
Export the selected feature: right click “
county_bnd
” -> Data -> Export
features -> Set “Export” as selected features and save the Output feature
class to ….\Maya.gdb, and name it as
guatemal.shp
.
Remove “
country_bnd
” from the Table of Contents to avoid clutter, as we
will no longer need it.
Step 3
:
Creating the ArcToolbox
ModelBuilder is accessed through ArcToolbox. It is one of the ways through
which users can customize ArcToolbox for their own needs. A ModelBuilder
can in fact be thought of as an ArcTool created by the user. The basic
procedure for creating a new, empty Model is to first create a new Toolbox,
and then create a new Model within that Toolbox.
In Catalog Window -> right click your data folder -> New -> Toolbox
Rename the new created toolbox as “
Maya_Toolbox.tbx
”
Right click “
Maya_Toolbox.tbx
” -> New -> Model
ModelBuilder window shows up, you will drag tools from ArcToolbox into
this window to build the Model.
Step 4
:
Building the ModelBuilder
Toolboxes -> Analysis Tools -> Extract -> Clip
Select the Clip function, directly drag it into ModelBuilder window, you will
get the following:
Double click the “Clip” rectangle to open up its setting window.
Input Features -> “rivers”
Clip Features -> “
guatemal
”
Output Feature Class -> …\Maya.gdb\
rivers_clip
.
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Prof. Kim
Click OK. You will see the model will become as following:
Click menu -> ModelBuilder -> Run
. In this way, you finished the
clipping geoprocessing in modelbuilder.
Step 5
:
Measure the proximity of sites to rivers
Now that the rivers feature class has been reduced to our study area, we will
add a procedure for determining how close the archaeological sites are
located to rivers.
Analysis Tools -> Proximity ->
Near, Click-and-drag it over into an open
area in the Model window. This function calculates the distance of points
from line features within a given search radius.
To make a connection: Hover over the variable that you want to connect
to a tool. The pointer changes to the connection pointer
. Click and hold
the mouse button while you move the pointer to the tool to make a
connection. When the pointer is above the tool, release the mouse button
and select the tool parameter to which the variable should be connected.
Connect the “
rivers_clip
” obtained in Step 5 to the “
Near
” rectangle, and
select “Near features”.
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Prof. Kim
Double-click the Near rectangle to open up its setting window.
Input Features -> “
arch_sites_14
”
Search Radius -> 5000 meters
Click OK.
The functionality of this tool: The Near tool will determine which points in
“
arch_sites_14
” are within a 5km distance of a river. For points that are 5 km
or less from a river, the specific distance (in meters) between the point and
the river will be entered in the attribute table of “
arch_sites_14
” under the
new NEAR_DIST column. For points that are not, a value of 0 will be entered
in the same attribute table column instead.
Step 6
:
Combine vegetation and soils feature classes
The next few steps in constructing our Model involve determining which
environmental attributes surround each of our archaeological sites.
Conceptually, we simply need to find out in which vegetation, soils, and
aspect polygons the sites reside. In practice, however, things are a little
more complicated than this. First, there is no single ArcGIS geoprocessing
tool that can determine the answer we need in just one step, so our analysis
requires a multi-step procedure. Second, all of these layers must be
combined into a single feature class before we can analyze them with the
archaeological sites data. Third, although you could use the Union tool (or
even Intersect) to combine the environmental attribute layers with one
another, you must use the Identity tool when you bring the archaeological
sites data into the analysis.
Q1.
Compare and contrast the Identity tool with Intersect and Union. Why is
Identity the necessary tool to use with the archaeological sites data?
(30
points)
We will first combine the forest vegetation and soils layers into a single
feature class. The Identify tool will be used in this and the following step for
simplicity and consistency.
Add Identity function (Overlay
Analysis Tools) into the Model window.
Double-click on the Identity rectangle to open up its setting window.
Input Features -> “
guatfor
”
Identity Features -> “
soils
”
Output Feature Class -> …\Maya.gdb\gfor_soils
Click OK. “
gfor_soils
” will now be shown as the active output of Identify in
the window.
Step 7
:
Add aspect data
Add Identity function (Overlay
Analysis Tools) into the Model window
again.
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Prof. Kim
Draw a connection between “
gfor_soils
” and Identity (2) rectangle and
select
Input Features
.
Double-click on the Identity (2) rectangle to open up its setting window.
Identity Features -> “
aspect
”
Output Feature Class -> …\Maya.gdb\gfor_soils_asp
Click OK. This step will combine the aspect layer with the output from
Step 6
into a single feature class.
Q2.
What is aspect? Provide the equation and explain how it is calculated.
Explain it with respect to elevation.
(20 points)
Step 8
:
Determine site attributes
Now that the three environmental attribute layers have been combined into
a single feature class, we can determine the surrounding attributes for the
archaeological sites.
Add Identity function (Overlay
Analysis Tools) into the Model window
again.
Draw a connection between “
arch_sites_14 (…)
” (the layer generated by
Near function) and Identity (3) rectangle and select
Input Features
.
Draw another connection between “
gfor_soils_asp
” and Identity (3)
rectangle and select
Identity Features
.
Double-click on the Identity (3) rectangle to open up its setting window.
Output Feature Class -> …\Maya.gdb\arch_sites_ID
Click OK.
Step 9
:
Simplify the output table
At this point, we are effectively done with all the necessary processing to get
our desired information about the archaeological sites. However, if we were
to examine the attribute table of “
arch_sites_ID
” at this stage, we would find
it a little difficult to pick out the specific information in which we are
interested. Due mainly to using the Identity tool, the attribute table now has
many more attribute columns in it than the four that we want to see
(distance from a river, forest vegetation type, soil fertility, and aspect). To
make things easier, we can use the
Frequency tool
to extract only those
attributes that we want and save the results in a separate (non-spatial) table.
Frequency also counts up the number of incidents of each case which is very
helpful when dealing with datasets that are too large to count up manually.
Add Frequency tool (Statistics
Analysis Tools) into the Model window.
Draw a connection between “
arch_sites_ID
” and Frequency rectangle and
select
Input Table
.
Double-click on the Frequency rectangle to open up its setting window.
Output Table -> …\Maya.mdb\
arch_sites_ID_Frequency
Under Frequency Field(s), scroll down and checkmark NEAR_DIST,
DESC_, R_FERT, and ASP_CODE.
Click OK.
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Prof. Kim
Because the Frequency table is the end product of our Model, we should set
it to be added to the display after it is created so that we can examine it.
Right-click on the green “
arch_sites_ID_Frequency
” output oval, If
“Intermediate” is turned grey, it is ok, if not please uncheck it, and also
check “Add to Display”.
Step 10:
Clean up the Model display
At this point your ModelBuilder window is probably looking a little messy.
Because one of the purposes of a ModelBuilder Model is to serve as a visual
aid for understanding the procedures involved, you should take a moment to
straighten up and organize your Model before we continue. You can, of
course, simply move around the various objects manually. There are,
however, two different tools provided by ModelBuilder to help organize the
display. One is the Overview Window, accessed via the Window menu. This
will bring up a small window showing you a miniature overview of your entire
Model. By adjusting the bounding box in the Overview Window you can
shrink or expand the size of the objects in the display.
The second organizing
tool is Auto Layout, located under the View menu.
Auto Layout will
automatically organize the objects in the display; however, it prefers to
stretch the Model out horizontally, which makes it difficult to view large and
intricate Models in their entirety. Regardless of whether or not your cleaned-
up Model matches this specific layout pattern, it should contain all of the
elements shown in the illustration below:
Figure 1.
Print out your Model. When you are done organizing the
ModelBuilder window, print a copy of your Model by clicking on the Print
button on the ModelBuilder toolbar.
(30 points)
Step 11:
Run the Model
We are now finally ready to run the Model. As a precaution, first make sure
that ArcCatalog is not currently running on your PC -- if it is open while you
run the Model, ModelBuilder may encounter problems.
Save your model first before running it (ModelBuilder -> Save).
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Prof. Kim
Click the Run button on the ModelBuilder tool bar
to run the Model.
A dialog box will pop up with a progress bar and scrolling display listing
each step as ArcGIS runs through them. In the ModelBuilder window each
tool function rectangle will turn red while it is being processed. When the
Model run is completed, click Close on the dialog box.
Step 12:
Examine results
The "
arch_sites_ID_Frequency
" table should now appear in the Contents
-> List By Source. (If it does not, add it to the display from the "Maya"
geodatabase.)
Right-click "
arch_sites_ID_Frequency
" -> Open.
Look through the table records. FREQUENCY lists the number of
occurrences of each configuration of the four other attributes (e.g. a value
of 2 means that two of the sites from "
arch_sites_14
" had the attribute
configuration listed in that row).
NEAR_DIST contains the proximity of the given site to a river -- either
the distance to the nearest river in meters, or a
-1
if the site is not
within 5 km of any river.
The three environmental variables derived from our Identity operations
are DESC_ (forest vegetation type), R_FERT (soil fertility), and
ASP_CODE (aspect).
You will notice that while the DESC_ field has meaningful descriptions
of the vegetation type, the latter two have only cryptic numbers in
their records. Here are keys (i.e. metadata) explaining the meaning of
the values in R_FERT and ASP_CODE:
Table 1
Soil Fertility Codes
(R_FERT)
1
High
2
Moderate
3
Low
4
Infertile
Table 2
Aspect Codes (ASP_CODE)
1
flat
2
North (0-22 deg.)
3
Northeast
4
East
5
Southeast
6
South
7
Southwest
8
West
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Prof. Kim
9
Northwest
10
North (337.5-360 deg.)
Try to develop some conclusions regarding what combinations of
characteristics (if any) seem to be the most commonly occurring. How useful
the Frequency column itself will be in this is unfortunately unpredictable -- it
depends entirely on the variability of your particular sample. Moreover,
because the NEAR_DIST field mostly contains specific, detailed distance
measurements there will probably be very few recurring identical values in
the column, and thus you will get many Frequency counts of 1. You will
probably find it more useful to sort the individual columns and count up the
number of occurrences manually. Do this by right-clicking on the column
headings in the table and selecting either Sort Ascending or Sort
Descending. Remember, however, not to look at each environmental
attribute in complete isolation! Although you do need to start by looking at
the attribute columns individually, your ultimate goal is to find combinations
of attributes.
Q3.
Write an analysis of the environmental characteristics of the Mayan
archaeological sites in the sample (minimum length of one pages, double
spaced, 12 fonts size). Your analysis must address the following:
(100 points)
What are the most common clusters of environmental attributes?
Does there appear to be any recurring pattern or tendency in the
data?
Give possible explanations for why certain combinations of
attributes seem to be more prevalent. Why might the Mayans have
preferred sites with these characteristics? What are the
shortcomings of this analysis -- its assumptions, weaknesses, etc.?
Are some of these environmental attributes interrelated? What
could be done to offset these possible problems?
In light of what your analysis has uncovered, come up with a
general outline for a predictive model of these sites. What factors
and ranges of their values would you suggest using?
Figure 2.
Produce graphics showing your output table of the Frequency
function.
(20 points)
For the Part II, you need to turn in the followings:
Figure 1 and 2 (50 points)
Answers to Question 1 through 3 (150 points)
PART III. Generating Line Features
You will assume the role of a recently hired GIS Analyst for
Bearcat Airways
in providing important spatial information for major US airports, flight routes,
and flight distances. You are required to generate flight routes for 25 major
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Prof. Kim
airports. The data you are provided with include:
Origin City, Destination
City, Distance, and Interaction (passenger flow)
. You are provided data
from the year 1973. You need to spatially generate the flight routes among
the 25 major cities, and answer the questions as directed.
Step 1
:
Examine the data
Add …\Part3\Data.gdb\
usa25cab_id
into ArcGIS Pro, open its attribute
table and
identify that each city has its own unique ID
(0-24).
Open
MATRIX_I_J_DISTANCE_INTERACTION.txt
with any text editor
(notepad or wordpad). Four columns represent:
First column [I – From City]
Second column [J – To City]
Third column [Distance]
Fourth column [Interaction=passenger between two cities]
Step 2
:
Project
usa25cab_id
and
US_state
Data Management Tools -> Projections and Transformations -> Project
Input Dataset or Feature Class ->
usa25cab_id
Output Dataset or Feature Class -> …\part3\Data.gdb\
usa25cab_pro
Output Coordinate System -> Projected Coordinate Systems -> UTM ->
NAD 1983 -> NAD 1983 UTM Zone 15N -> Click OK
Use the same procedure to project the
US_state (tl_2010_us_state10)
,
and save the projected file in
…\part3\Data.gdb\Data.gdb with name
US_state_pro
.
Go to
Contents
-> right click
Map
-> Properties -> Coordinate System ->
XY Coordinate Systems Available -> UTM -> NAD 1983 -> NAD 1983 UTM
Zone 15N -> Click Ok.
Remove the
usa25cab_id
and
tl_2010_us_state10
layers from the Table
of Contents because we only need to use the projected data.
Step 3
:
Generate lines for all pairs (600) among cities. Your job is to
generate 600 (25*24) lines on top of 25 cities. You will use
Generate Near
Table
and
XY to Line
tools to generate the lines in ArcGIS Pro.
Analysis Tools -> Proximity -> Point Distance.
Input Features -> usa25cab_pro.shp
Near Features -> usa25cab_pro.shp
Output Table -> …\part3\Data.gdb\Data.gdb\point_dis
Click Run
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The FID number of the Origin cities
The FID number of the destination cities
Prof. Kim
Go to Contents (List By Source) -> right click the generated point_dis
In this table, the INPUT_FID field is the FID value of the origin cities, and
the NEAR_FID field is the FID value of the destination cities. Now we need
to add the XY coordinates of origin cities and XY coordinates of
destination cities to generate lines between origins and destinations.
In the point_dis table, Add field, use this function to add the following
fields to this table:
Name: o_xcoor; Type: Double
Name: o_ycoor; Type: Double
Name: o_id; Type: Short Integer
Name: d_xcoor; Type: Double
Name: d_ycoor; Type: Double
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Prof. Kim
Name: d_id; Type: Short Integer
Name: id_line; Type: Short Interger
Join usa25cab_pro.shp to point_dis table
Right click point_dis table -> Joins and Relates -> Join, set up as following:
Input Join Field: INPUT_FID
Join Table: usa25cab_pro
Join Table Field: FID
Open the point_dis table, use Field Calculator to calculate the field values
for o_xcoor, o_ycoor, o_id separately:
point_dis.o_xcoor = [usa25cab_pro.X_COORD]
point_dis.o_ycoor = [usa25cab_pro.Y_COORD]
point_dis.o_id =
[usa25cab_pro.ID]
Right click point_dis table -> Joins and Relates -> Remove Joins ->
usa25cab_pro
Join usa25cab_pro.shp to point_dis table again but with different common
field
Right click point_dis table -> Joins and Relates -> Join, set up as following,
notice that we use “NEAR_FID” as common field this time
Input Join Field: NEAR_FID
Join Table: usa25cab_pro
Join Table Field: FID
Open the point_dis table, use Field Calculator to calculate the field values
for d_xcoor, d_ycoor, d_id separately:
point_dis.d_xcoor = [usa25cab_pro.X_COORD]
point_dis.d_ycoor = [usa25cab_pro.Y_COORD]
point_dis.d_id =
[usa25cab_pro.ID]
Right click point_dis table -> Joins and Relates -> Remove Joins ->
usa25cab_pro
Open the point_dis table, use Field Calculator to calculate the field value
for id_line:
id_lines = [OBJECTID]
Now we need to use this table to generate the lines between those 25 cities
according to the x,y coordinates of the origins and destinations.
Data Management Tools -> Features -> XY to Line
Input table -> point_dis
Output Feature Class -> …\part3\Data.gdb\Data.gdb\OD_lines
Start X Field -> o_xcoor
Start Y Field -> o_ycoor
End X Field -> d_xcoor
End Y Field -> d_ycoor
Line Type (optional) -> GEODESIC
ID (optional) -> id_lines
Spatial Reference(optional)->GCS_North_American_1983 (
This is
important!!!
)
Click OK.
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Prof. Kim
Now we have generated the lines between origins and destinations with
geographic coordinate system, we need to project this file as
NAD 1983
UTM Zone 15N.
Data Management Tools -> Projections and Transformations -> Feature
-> Project
Input Dataset or Feature Class ->
OD_lines.shp
Output Dataset or Feature Class -> …\part3\Data.gdb\
OD_lines_pro
Output Coordinate System -> Projected Coordinate Systems -> UTM ->
NAD 1983 -> NAD 1983 UTM Zone 15N -> Click OK
Step 4
:
Open the attribute table, you will notice that the generated lines
only contains the following information.
(The figure is captured by ArcMap)
Your job is to give interaction flows, origin, and destination for
those lines
. You should not input values manually. First of all, you may make
a mistake when you manually input those numbers. Secondly, there are too
many records to input. Therefore, you need to find an efficient and secure
way. Remember the 600 lines that you generated have id_lines field which
can be used to associate with the
point_dis
table. Thus it is possible to add
the origin ID and destination ID information to this line layer (OD_lines_pro)
by joining with
point_dis
table. You need to create an
INTERACTION
geodatabase table (create this in Data.gdb instead of a standalone dbf; it
later causes errors) converted from
MATRIX_I_J_DISTANCE_INTERACTION.txt.
You can use this file to add the
interaction and distance information to the line layer (
OD_lines_pro
). The
INTERACTION
table contains the origin ID and destination ID.
TIP:
You have to make a common field using o_id and d_id (e.g. o_id*100 +
d_id) between OD_lines_pro.shp and INTERACTION.dbf. After both files have
this field (named perhaps Join_Id), then you can join based on that field in
each.
TIP:
Create new attribute fields in OD_lines_pro before joining the
INTERACTION table. Make a careful decision what data type for the created
Interaction attribute! Choose the wrong type, and you’ll end up with NULL
values for some records.
After this step, your attribute table of the line layer (OD_lines_pro) should be
like following:
15
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Prof. Kim
According to this table, you can calculate the overall numbers of flow-ins and
flow-outs respectively for each city.
Q1.
Describe the exact procedure how you associate those interaction
among cities into the OD_lines_pro.shp?
(30 points)
Q2.
Describe the exact procedure how you can calculate the overall numbers
of flow-ins and flow-outs respectively for each city?
(30 points)
Map 1.
Create a nice map showing 25 cities with lines (48) coming in and
out of
Cincinnati, OH
. Label the flows on the arcs and cities in the points.
Make sure 48 states polygons are projected in
NAD 1983 UTM Zone 15N. Do
not include Hawaii and Alaska.
(50 points)
Map 2.
Create a nice map showing 25 cities with lines whose interaction has
more than 25,000. Clearly label the flows on the arcs and cities in the points.
(50 points)
Step 5
:
Calculate the length of lines. Open the attribute table of
OD_lines_pro, add a new field named
Arc_Length
with data type as
double
.
Right click this field and select “Calculate Geometry”. Click “Yes” if any
warning window pops up. In the “Calculate Geometry” window, select
Mile
as
the unit, click OK.
Q3.
Now you realize that distances that you have in your lines are different
from the ones in “
INTERACTION.dbf”
file. Explain why we end up with
different distances? Is this really critical in terms of analysis? Calculate
differences between your distance and my distance, and add all (600) of
them. Provide the numbers that you come up with.
(30 points)
16
Prof. Kim
Step 6
:
Now we are interested in visualizing the network in ArcScene. Make
3 different layers. [1] all the arcs coming out of
Cincinnati
, which have more
than
5,000
interaction, [2] all the arcs going into
Atlanta
, which have more
than
5,000
interaction, [3] all the arcs coming out of
Denver
, which have
less than
5,000
.
Step 7
:
Add those layers in ArcScene. Make
Cincinnati
the top layer,
Atlanta
as the mid layer, and
Denver
as the bottom layer (
Refer to the
slides provided by TA
).
Q4.
Explain the procedure how you visualize those 3 layers in ArcScene?
(20
points)
Q5.
Experiment with different orders among three cities (airports). Discuss
which order is best to visualize the patterns in ArcScene?
(20 points)
Q6.
Discuss how 2D and 3D mapping are different regarding Q5?
(20 points)
Map 3.
In ArcScene
,
Create a nice map of three layers showing 25 cities
(from/to Cincinnati, Atlanta, and Denver).
(50 points)
For the Part III, you need to turn in the followings:
3 maps (150 points)
Answers to Questions 1 through 6 (150 points)
17