The Human Population: Patterns, Processes, and Problematics

GEOG 2401

Dr. Paul Sutton

Lab Exercise 1: Exploring Census 1990 data for the Denver metro areas using ArcGIS

In this lab we are exploring 1990 U.S. Census data to understand how it is collected and stored. We will be analyzing the population of the Denver metro area and looking for patterns. This lab is to gain an understanding of population density, what it means and how it relates to the Denver area. You will be using a geographic information systems (GIS) software program named ArcGIS. GIS helps create maps and tables about geographic information in order to visually interpret the data. Follow each of the steps below in the correct order and answer the questions to complete the lab.

  1. What is population density, what does it mean in comparison to the basic population of an area?

______

  1. Open the ArcGIS program by selecting Start -> All Programs -> ArcGIS -> ArcCatalog

On the left you will see a series of drives that are currently connected to the program, this is how we bring data in to ArcGIS, on the right you will see a blank white area with tabs across the top: Contents, Preview, Description

  1. Click on the “Connect to Folder” button
  2. At the Connect to Folder window Click on “Nsm\gis on du shares (I:)” and OK, this step connects the drive with our data on it to the program, you will see a series of folders appear on the right side of the window under Contents
  1. Double click on the folder that is labeled ‘Courses’, ‘Core 2401’, then ‘Weaver ’,then ‘Labs’ then‘Lab_1’ now, on the right side of the window a series of data will appear that look something like the following:

Another way to get this data is to download a zip file from the course web page and extract it onto your laptop or local lab computer. (Click on “Lab 1 for a zip file.)

  1. Select one of the data files by clicking on it then click on the “Preview” tab, a picture will appear that shows you what that data file contains

What do you see in the file you selected to preview?

______

Now at the bottom underneath the picture is a pull-down menu that currently should say Geography, click on the arrow and select Table.

What do you see, and what data do you think this table contains?

______

  1. At the top in the toolbar is an icon that will open ArcMap, click on this icon:
  1. As ArcMap opens up, be patient it takes time, at the first window select ‘Blank Map’ then click OK, after ArcMap opens click on the middle box in the upper right corner of the window to make the window smaller:
  2. Have both ArcMap and ArcCatalog open on the screen with ArcCatalog the active window (on top)
  3. On the left side of the ArcCatalog window under Catalog, where all of the drives and data files are listed, select one of the data files in our folder by clicking on it and holding the mouse button down, drag the file onto the ArcMap window under the heading Layers or you can click on the ‘add data’ icon.

  1. Repeat step 10 until all of the files have been dragged over to the ArcMap window.
  • Note: To keep the Table of Contents from disappearing in ArcMap, click on the Pin icon at the top of the TOC
  1. Click on all of the ‘check marks’ next to the data so that they disappear from the View, now click on the box next to County so that it appears in the View

What do you see? ______

  1. Right mouse click on the title Counties, and select Properties
  1. Click on the tab that says ‘Symbology’, on the left side of the window under Show, click on Categories and then Unique values

15. Under the ‘Value Field’ pull down menu select NAME, then click on the ‘Add All Values’ button, then click on Apply, then OK

  1. What do you see on the ArcMap window, what did you just accomplish in the Properties window? ______
  2. At the top of the window is your toolbar, just like in Microsoft Word

click on the blue circle with the ‘i’ inside of it, this is the identify tool, now click on one of the counties, what happens and what do you find out?

______

  1. On the left side of the window, uncheck the box next to ‘counties’ to turn it off, and check the box next to ‘tracts’ so that a new map appears, now we are going to look at population density, income levels, as well as ethnicity maps.
  2. Right mouse click on ‘tracts’ and select Properties, this time on the left side click on ‘Quantities’ then ‘graduated colors’, in the drop-down list next to ‘Value:’ select PERSONS, and next to ‘Normalization’ select LAND_KM, then click Apply and OK

What did we do when we placed LAND_KM in the Normalization box?______

What type of a map did you just create? ______

Where are the largest numbers located and why?______

Why do you think this area has large numbers? (not just because lots of people live there)

______

What other patterns do you see in the map?

______

Using the Identify tool again click on one of the tracts and determine the name of the county that tract is in and the number of persons that live there.

______

  1. Turn off the ‘tracts’ map and turn on the ‘DenverMetroblockgroups’ map (not blocks), repeat step 18 with this map but you will not need to normalize by Land_KM because population density is pre-calculated in the table. The population density fields are POP00_SQMI and POP04_SQMI, pick one to symbolize the map.

What is different between the two maps?

______

What is the spatial hierarchy of census data?

______

Look at the ‘DenverMetroblocks’ map without changing the Properties of it, where does it fit in the hierarchy?

______

  1. Turn on only the ‘tracts’ map, once again right mouse click on tracts on the left side of the window and select Properties, this time change the ‘Value’ drop down list by scrolling down to find INC_MEDN, this is the income values for each tract, then change the normalization to NONE, click Apply then OK

What type of a map have we created now?______

What are the patterns of income distribution you see? Where is there high income and lower income?

______

Use the + magnifying glass on the toolbar and drag a box around the county of Denver to zoom in, what types of patterns do you see in the city, and why?

______

  1. Right mouse click again on ‘tracts’ and select Properties, this time change the Value: to HISPANIC and the Normalization: to “Persons”

Again what types of patterns do you see within the county of Denver, around the city, are there any relationships that you see?

______

  1. Zoom out by clicking on the tool that looks like the world

What patterns do you see across all of the counties?

______

  1. Select another ethnicity from the drop down list next to Value and create another map that shows the distribution of another ethnicity, discuss any patterns you see.

______

Additional Questions: Connecting Lecture to Lab

24. Please state two ways in which maps such as these helpful in understanding demography and population on a local city level? How might it help us on a global level?

26. In number 18 of this Lab you used a process called "Normalization." What is it? Why is it important to normalize data ? Please give one specific example of data you would normalize in mapping and why. Please refer to document in the Lab 1 folder called Normalizing Data to answer this question.

25. Why does Dr. Sutton think that population growth is related to global warming? (Please a couple of his arguments presented in class.) Do you agree or disagree? Why? What maps might be helpful in proving your ( or his) point? (write on back)