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InstantWorld: Locating an Internet Café in Houston, Texas Author: Joseph J. Kerski, Geographer, USGS, jjkerski@usgs.gov, 303-202-4315 Your Name: _______________________________________________ Date:
___________________________ Summary: In this
lesson, you will use demographic data, roadways, and proximity to
schools and universities to locate three Internet Cafes in Houston,
Texas. GIS Skills Involved:
1)
Downloading, formatting, and understanding Census TIGER / demographic
data. 2)
Creating and plotting map layouts. 3)
Tabular and spatial sort and query. 4)
Joining tables. 5)
Geocoding addresses. 6)
Solving multiple problems using GIS and spatial analysis. 7)
Digitizing Features. 8)
Overlay.
This lesson uses ArcView 3.x GIS software from ESRI, Inc., but the spatial concepts can be translated to other GIS packages. Acquiring and Managing Data Create a folder on your computer where you will store the data named harriscounty. Make sure this folder does not contain any spaces. In this lesson, you will download all of the data from the Internet.
Note:
You will be downloading just over 9 MB of data. If your instructor
has already downloaded the data for you, proceed to question 1 below.
Go
to the following web site: http://www.esri.com/data/download/census2000_tigerline/index.html
Click
on “Download Data” and on the next screen, select Texas on the map
or via the list.
On
the next screen, select Harris County and press “Submit.”
Do not select any layers yet.
On
the next screen, click the following 3 boxes, and then press “proceed
to download” at the bottom of the list:
Block
Groups – 2000 Line
Features - Hydrography Line
Features – Roads Census
Block Group Demographics (Under “statewide layers”).
Select “Proceed to Download.” Next, you will receive a notice that your data file is ready, as follows:
Click
Download File to retrieve your data to the folder you created at the
beginning of this lesson.
Unzip
the file with Winzip. Note
that there will be three files that are zipped underneath this zip file.
In other words, the file you downloaded is a zip containing 4
zipped files and a readme file. These
are named: grp0048201.zip lkA48201.zip lkH48201.zip sf1grp48000.zip readme.html Be
sure to Unzip each of the files and extract. When you are finished, you
should have 11 new files:
tgr48000sf1grp.dbf tgr48201grp00.dbf tgr48201grp00.shp tgr48201grp00.shx tgr48201lkA.dbf tgr48201lkA.shp tgr48201lkA.shx tgr48201lkH.dbf tgr48201lkH.shp tgr48201lkH.shx readme.html The
Federal Information Processing Standard (FIPS) code for Texas is 48.
1) What do you surmise the FIPS code for Harris county to be? Read
the table that is in the file called readme.html to answer the following
questions:
2) In which file are the spatial coordinates for the roads?
The
U.S. Census Bureau collects data for statistical areas and political
areas. Political areas
include Indian Reservations, cities, counties, and states.
Statistical areas include Census Tracts, Block Groups, and
Blocks. Blocks in a city or
town are usually the same as a typical city block, bounded on all sides
by streets. Blocks in a
rural area may be much larger in area, and may be bounded by roads,
streams, or a railroad. Groups
of blocks are called Block Groups.
Groups of Block Groups are called Census Tracts.
Census Tracts nest within counties.
Block
groups are analogous to neighborhoods; they are the smallest statistical
area for which the more detailed Census data is available.
You have just downloaded the Block Groups for Harris County.
3) In which file are the block group boundaries?
4) In which file is the Census data for the Block Groups?
5)
In what year was the data collected?
Start
ArcView with new project and new view.
Add
all of the themes you downloaded above to your view:
Hydrography Roads Block
Group boundaries Name
your view “Harris County” under View--> Properties. Under
the same menu, set your display units to kilometers. Save
your project Your data sets are now ready to analyze.
Use Theme--> Properties to change the name of your tgr48201lka.shp file to Streets. 6) Make two observations about the pattern of streams in Harris County.
7) What general direction do the rivers flow in Harris County? Why?
Zoom in on downtown Houston and use Theme--> AutoLabel to label the streams (on the field fename).
8) What is the name of the main stream that flows through downtown Houston?
Use Theme--> Remove Labels.
9) Make two observations about the street pattern in Harris County in relationship to downtown. Discuss the effect that downtown has on the layout of the streets.
10)
Using the interactive label tool,
11)
Double click on the roads theme to make a unique value map for
streets, symbolizing the roads based on the attribute field cfcc2.
Zoom in on different areas of your map when you are done, using
the “I” identify button to answer the following:
What is the code for CFCC2 for the three most major road types in
Harris County?
12)
What other kinds of attribute information does the streets theme
contain?
Go
to the Project Window (that shows views, tables, layouts, and so on).
You can use the Window pull down menu to select the project window,
named Select:
Tables. Add. Add
the table containing your Census data for Block Groups.
Open this table and examine the data. 13)
How many records does the table have?
Open
the table the Block Group boundaries layer.
14)
How many records does this table have?
15)
What geographic extent do you think the longer table covers?
Clear
any selected records in both tables. 16)
What is the name of the field that these two tables share that
contains the same data?
Joining Tables to Analyze Additional Data To map detailed
demographic data, you need to join
the 2 tables. It is very important to do the join in the
correct order. You want to join FROM the table you just added (the
tgr46000sf1grp.dbf) TO the table associated with the map (attributes of Tgr46121grp00.shp First, click on the join field in the tgr46000sf1.grp table. Second, click on the join field in the table attributes of tgr46121grp00.shp. Third, click on
the “Join Tables” button. (looks like 2 tables with an arrow
joining them)
Now, examine your attributes of the block group table. 17)
What happened to your tables after you joined them? 18) Look at the columns in your joined table. Is it wider or narrower than before?
19) Why?
20)
Examine the number of rows in the table, listed to the upper left of the
data. How many block groups exist in Harris County? Save
Siting GIS Clubs for Houston Independent School District: Age The Houston Independent School District (HISD) is the largest public school system in Texas and the 7th largest in the United States. HISD has contracted with you to determine the best locations to start after-school GIS Clubs. In the clubs, students will work on community-based issues, do field work, and map social and physical characteristics of the neighborhoods with GIS and GPS. HISD will start these clubs only in selected areas in the district. Therefore, you need to determine where concentrations of the school-age population reside. Begin analyzing the school-age population. Double-click the theme legend and make a graduated color thematic map that shows the population of the 5 to 17 year olds, the "school-age" population. 21) Make at least two observations about the pattern of the 5 to 17 year olds in Harris County. 22) Zoom in on downtown Houston. What do you notice about the relative number of school-age population here versus elsewhere in the county?
23) Would you think that there are more schools in the typical downtown neighborhood or more schools in the suburbs? Why? You have been making
maps of total 5-17 year old population. Next, make a map of 5 to
17-year-olds as a percentage of the total population.
Do this by normalizing your data to that of the total 2000
population, as in the screen below. Use
24) Which three block groups contain the highest percentage of 5 to 17 year olds, and what are their percentages? 25) Where are these block groups located? 26)
In which part(s) of the county are you thinking of recommending
the GIS Clubs to the School District? 27)
Why?
28)
Create a layout using View
—> Layout. Create
your layout. With the text tool Print the
layout.
Comparing Classification Schemes Data can be classified
in many ways on a map. Changing how the data is classified may
enhance understanding of the phenomenon being mapped. The way data
is classified may even distort understanding of a phenomena. All
of the maps that you have been making thus far use the classification In the legend editor, click on the "classify" button on the right. Change the map of percentage of 5 to 17 year olds from natural breaks to Quantile and Apply. A quantile classification places the same number of observations (in this case, block groups) in each category. Look at your answer to the above question about how many block groups are in Harris County. 29) You have 5 classes. Therefore, how many block groups are in each of the classes in Harris County?
30) Make 2 observations that compare the quantile map of school age population to the natural breaks map.
Change the classification to Equal Area. This classification places the same geographic area in each of the classes. 31) Make 2 observations that compare the Equal Area map of school age population to the natural breaks map.
Change the classification to Equal Interval. This classification divides the range of data into equal intervals for each class. 32) Make 2 observations that compare the Equal Interval map of school age population to the natural breaks map.
33) What is the range of the percentage of 5 to 17 year olds for each class, using the Equal Interval method?
34) Is the interval the same for each class? Why or why not?
Change the classification to Standard Deviation. ArcView finds the mean value and then places class breaks above and below the mean at intervals of either 1/4, 1/2, or 1 standard deviations until all the data values are contained within the classes. 35) Make 2 observations that compare the Standard Deviation map of school age population to the natural breaks map.
36) In your opinion, which of the five classification methods that you have used above help you to best understand the distribution of school age population in Harris County? Why?
37) Do any of these other classification methods make you change your recommendation on where to start the GIS Clubs?
Leave your classification method as Standard Deviation. Save Comparing Map Types You have been changing
the classification methods. In this section, you will change the
map type. Change your
legend so that you can make a pie chart map.
Use the guide below to create pie charts indicating the
proportion of 5 to 17 year olds in the total population:
Next,
double click on the theme name again to pull up the legend editor.
Use the “properties” button in the lower right of the legend
editor and make the 2000 population the size field for the pie charts. 38)
What effect did the size property have on the map?
Next,
change the legend one more time to make a dot map with 1 dot for every 1 five-to17 year old person.
Describe this map. 39)
In your opinion, which of the maps—graduated color, pie chart,
or dot map—is the easiest to understand? 40)
Why? Save Siting GIS Clubs for Houston Independent School District: Racial Characteristics The Houston Independent School District is pleased with your recommendation on where to begin the GIS Clubs. Now, they want you to determine the best location for the clubs that would meet the diversity of the Houston-area population. Use the graduated color map type, standard deviation classification method, and reds-to-blues dichromatic color ramp throughout this section. Create a map of the percentage of African Americans (Black normalized by Pop2000). 41) Make two observations about the population distribution of African Americans in Harris County.
Create a map of the percentage of Hispanic Americans (Hispanic normalized by Pop2000). 42) Make two observations about the population distribution of Hispanic Americans in Harris County.
Create a map of the percentage of Asian Americans (Asian normalized by Pop2000). 43) Make two observations about the population distribution of Asian Americans in Harris County.
Create a map of the percentage of Native Americans (Ameri_es normalized by Pop2000). 44) Make two observations about the population distribution of Native Americans in Harris County.
Create a map of the percentage of Multiracial Americans (mult_race normalized by Pop2000). 45) Make two observations about the population distribution of Multiracial Americans in Harris County.
46) Which two racial groups are the most concentrated in Harris County?
47) Which two racial groups are the least concentrated in Harris County?
48) Write in your own words about some of the benefits of racial concentration, and what are some of the challenges that racial concentration brings in a metropolitan area.
A GIS allows you to compare multiple variables at the same time. Say you wanted to begin recommending where the GIS Clubs should be located to best serve Hispanic Americans. You will query your database to select the neighborhoods that have a high percentage of school aged population and a high percentage of Hispanic Americans. First, change your map to Single Symbol, using any color. Next, use
the Query tool
Open the
theme table 49) How many neighborhoods are selected?
50) Examine your map. Where are the neighborhoods containing over 25% school aged population?
Again,
use the Query tool Open the
theme table 51) How many neighborhoods are now selected?
52) Examine your map. Where are the neighborhoods containing over 25% school aged population and over 50% Hispanic American population?
53) In which areas of Houston will you recommend GIS Clubs to be started to best address the Hispanic American community?
Clear
your selection. Repeat the above procedures for the African American community. 54) How many neighborhoods were selected?
55) Examine your map. Where are the neighborhoods containing over 25% school aged population and over 50% African American population?
56) In which areas of Houston will you recommend GIS Clubs to be started to best address the African American community?
Clear
your selection. Repeat the above procedures for the Asian American community. Use 20% rather than 50% for the second query; that is, select neighborhoods with over 20% Asian Americans. 57) How many neighborhoods were selected?
58) Examine your map. Where are the neighborhoods containing over 25% school aged population and over 20% Asian American population?
59) In which areas of Houston will you recommend GIS Clubs to be started to best address the Asian American community?
60) Why do you suppose you had to lower the concentration percentage for Asian Americans?
Save Comparing Demographic Characteristics In this section, you will compare across other variables to see how they are related. Make a graduated color map of Median Age. 61) Note the area to the east-southeast of downtown with a high median age. Name at least three types of businesses that these neighborhoods would have more of than other areas of the county.
62)
Which areas of Harris County have the lowest median age?
63) Make a map of Average Family Size. Compare this to the median age map and explain the relationship between the two maps. 64)
What block group had the largest average family size? What was the
average family size in that block group? In what part of the
county is it located?
Examine your data; then think about and examine the following questions. If you would like to, you can copy one theme, paste it, and change the variable mapped in one of the themes. That way, you can click on and off themes to examine characteristics from both. 65) What is the relationship between median age and average family size? What is the reason that this relationship exists?
Clear
your selection. Determining the Best Location for Internet Cafes in Houston You have been contacted by InstantWorld, an Internet Cafe company that markets to school. The company wants to open three franchises in the Houston area. You need to analyze your data in a GIS environment to recommend the three best locations for the businesses. In this section, you will use the geocoding feature of ArcView GIS. Any GIS can automatically locate features on a map using street addresses. You need two things: (1) an address list, and (2) a geocodable street theme. You already have the second item. Zoom in
on a few streets in Mission on the map and examine them in
the associated table, using the identify feature button.
67)
What
do you think the fields faddl, taddl, faddr, and taddr mean? Your streets layer is geocodable; that is, you can use it to locate addresses. To do this, you first need to set it up, as follows:
Access
the Theme-->
Properties menu for your streets layer.
Go to the Geocoding function and set the address style to US
Streets, as follows. Select
OK and Yes at the prompts. In the view, select the push-pin symbol
69) In what part of Houston is the school district headquarters?
70)
Use the label tool 71) Enter another address. Try entering your own address if you live in Houston. If you do not live in Houston, try 901 Bagby. Examine the web page: http://www.ci.houston.tx.us/citygovt/mayor/map.html. What building is located at 901 Bagby?
Save InstantWorld,
which seeks to open an Internet Café in Harris County, through a
national study, indicates that its Internet Cafes do best in the
following neighborhoods: 1)
Within 1 km of
a high school. 2)
Within 2 km of a university or college. 3) In a neighborhood where the percent of 18 to 21 year olds is over 10 % of the total population of the neighborhood, because the Internet Cafes will be designed primarily for this age group. 4) On a busy street (with a CFCC2 code of A1, A2, or A3) to attract customers and to comply with zoning regulations. Before
geocoding, it is a good idea to become more familiar with your
geocodable file. In
our case, it is the streets shapefile.
Access the table for this theme, scroll to the top of the table,
and click in the third record that has a TLID of 95999137.
Click in the map and use the zoom to selected tool
to zoom to this street segment. 72) What is the name of this street?
73) What is the field containing the name of the street called?
74)
What is the Starting Address on the left side of the street
segment? (FRADDL) 75)
What is the Ending Address on the left side of the street segment
and what is the field named? 76)
What is the Starting Address on the right side of the street
segment and what is the field named? 77)
What is the Ending Address on the right side of the street
segment and what is the field named? 78) Based on what you can determine from this street, which sides of the streets in Houston are even? North and West, North and East, South and West, or South and East? Clear your selected street. You are ready to geocode addresses. First, you need to find out where the high schools are located. You do not need to manually spot them on your map of Houston. Rather, because a listing of these schools exists online with the addresses of the schools, you can use these addresses to geocode the schools to specific locations on the map. This is possible because the TIGER file (the streets) contains address ranges for each street section. Click here to download the names and addresses of the Houston ISD high schools. Save this file to the same folder as where your other data is located. The file is named highschools.txt. Make Streets the active theme. Select the View--> Geocode Addresses menu. Make Streets the Reference Theme, using Address Style "US Streets", and browse to locate your address table "highschools.txt" in your folder. Make your Geocoded Theme hs_geocoded.shp and store it in your data folder, as follows:
79) How many high schools matched with a "good match"? How many high schools matched with a "partial match"? What is the total of "good match" plus "partial match?"
Notice that you now have a new theme named hs_geocoded. Change the symbol so that high schools will be symbolized with a red flagpole at point size 24. Your map will look similar to the following:
80) Examine the spatial extent of the high schools on your map. Why do you suppose there are no high schools in the Houston Independent School District outside of the central part of Harris County? Hint: Examine the outer school district boundary on the map on: http://dept.houstonisd.org/ab/2002-2003/HS/HighSchools02.htm
Examine
the table of your high school geocoded theme. 81) How many records are in this table? Compare this to your sum of "good" and "partial" matches above and explain the reason for your results.
Recall that the first criteria for your Internet cafes is to locate them within 1 km of high schools. Therefore, you need to buffer the high schools to create 1 km areas around them. Go to Theme--> Create Buffers. Buffer the features of your theme hs_geocoded.shp, as follows:
Select Next. On the next screen, buffer the high schools at 1 kilometer, as follows:
Select Next. On the next screen, dissolve buffers and save in a new theme named hs_1km_buffer.
Select Finish. Save 82) Examine your new map of the high school buffers. What shape are they? Why?
Go to the Edit menu, and Select All Graphics. Then press the Delete key on your keyboard. Save your
project. Next,
recall that the second criterion for the Internet Cafés was to locate within
2 km of universities.
You will be adding these universities as dots on the map
(digitizing) to develop additional skills, but you could just as
easily geocode their addresses as you did the high schools, earlier. First, go to the View menu and select New Theme. Indicate that it will be a point theme and save it in your data folder with the name universities. shp. Notice that it has a dotted line around it, indicating that you are in edit mode. Next, in
your View, pull down the "dot" on the right hand side of the
toolbar: Select the dot. Using the latitude-longitude display in the upper right as your guide, move to the following location: Latitude 29.69, Longitude -95.51. Don't worry about pinpointing the point accurately now; you will have the opportunity to adjust the point in a moment. Left click on the map to add the point. Because you need to make these points as accurate as possible, to reflect the true location of the universities, after you add the point, right click on the point to access the "Shape Properties" dialog box, as follows:
In the following dialogue at lower left, select Edit. In the lower right box, type in the coordinates as shown below:
The point is now added. This is the location of Houston Baptist University. There are 5 additional major universities in Houston. Add them as you did the first one. The locations are listed in the table below.
When you
are done, use the Theme--> Stop Editing menu, and Save Edits.
83) Why do the longitude numbers have to be negative?
Optional: If you would like to add a field to the table attached to your universities theme, go to Table--> Start Editing, and Edit--> Add Field. Define your new field as text and add the university names as listed above, making sure that you add the correct name to the correct point. If you have time constraints or have trouble digitizing the universities, and want to download the completed universities file, click here to download and save the file, unzip, and add universities as a theme to your view. Save 84) What side of Houston are the major universities located --north, east, south, or west?
85)
Examine the table of your universities theme Recall that your Internet Cafes will be located within 2 km of the universities. Buffer the universities to 2km as you did with the high schools, earlier. Name your resulting theme univ_2km_buffer. 86) Name at least two characteristics of the resulting map.
Next, you will combine your high school buffers with your universities buffers to generate a map showing areas near high schools and near universities. To do this, go to the File--> Extensions menu and check on the box to the left of Geoprocessing. The geoprocessing extension can now be accessed by selecting the View pull-down menu and then Geoprocessing Wizard. In the Geoprocessing Wizard's first screen, select Intersect themes. In the second screen, intersect your universities buffer with your high schools buffer, saving the result in a theme named hs_univ in your data folder, as shown below:
87) Turn off your high schools and universities buffers. Examine the new hs_univ theme and name at least two characteristics of the resulting map.
You have
completed the first two criteria for the Internet Cafe locations. The third
criteria is for a neighborhood where the percent of 18 to 21 year olds
is over 10 % of the total population of the neighborhood. Then, use
the Query tool
88) Explain what this formula does.
89) Examine your map. Describe at least two characteristics of the pattern of the neighborhoods with a high percentage of 18 to 21 year olds.
Next, combine the areas near high schools and universities with the neighborhoods with many 18 to 21 year olds, as follows: First,
make hs_univ your active theme by single-clicking on it. Clear Second, Use the Theme--> Select By Theme menu to select features of hs_univ that intersect the selected features of neighborhoods, as follows:
Select New Set when completed. 90) Describe at least two characteristics of your resulting map.
The areas selected near high schools and universities are now only those neighborhoods with a high percentage of 18 to 21 year olds. Now you
have 3 of the 4 required criteria.
Recall that the final criteria is on a busy street, with a CFCC2
code of A1, A2, or A3.
Then, use
the Query tool Select New
Set. 91)
Examine your table Use the "Select By Theme" function as you did above on the hs_univ theme. Select hs_univ polygons that intersect your busy streets. 92) Describe how you accomplished the above.
With your hs_univ the active theme, use Theme--> Convert to shapefile to permanently save your results. Store in your folder and name it internetcafes. 93) How many areas (polygons) are under consideration?
94)
Use the measure tool
95) Which university are most of the neighborhoods under consideration clustered around?
96) Which high schools are most of the neighborhoods under consideration clustered around?
Examine the neighborhoods that are under final consideration. They should look similar in distribution to the following map:
Save 97) Write a paragraph describing the locations and the characteristics of the neighborhoods you will recommend as sites for Instant World. Select three locations in those neighborhoods, indicating the name of the busy street that these will be located on, and justify why you believe these will be the best three sites for your Internet Cafes.
98) What other considerations would you think that franchises use to locate new businesses? What special considerations should an Internet Cafe have that other businesses do not consider?
99)
Create a layout containing your final criteria along with the
major roads and any other reference data you think is appropriate.
Print it and turn it in with these lab sheets. 100)
Summarize in a few sentences what you have learned about locating
businesses in this
lesson.
101)
Summarize in a few sentences what you have learned about site selection
in this lesson. Back to RockyWeb GIS in Education
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U.S.
Department of the Interior
U.S. Geological Survey Rocky Mountain Mapping Center Maintainer: webmaster@rockyweb.cr.usgs.gov URL:http://rockyweb.cr.usgs.gov /public/outreach/gislessons/internetcafelesson_houston_av3.html Last modified: 18 February 2004 |
,
what is the name of the inner loop freeway that encircles central
Houston?
,
as shown below:
, add your name, date, and change
the title of the map to something that reflects what the map is showing.
to find the neighborhoods with a high percentage (over 25%) of school
aged population. Use the formula as shown and select New Set
in the box below:
. 
(to the left of the query 
.
Zoom out a bit 
to see some of the surrounding streets. Use the identify button 
to measure the distance from one end of your neighborhoods under
consideration to another. How far is it?