Geography 417

Step 5. Examine the map, the legend and answer the questions in the response boxes provided below.

1. Which county has the highest population density in California?...It's a trick question...you have to zoom in a bit on the Bay Area.. (1) .

2. According to the legend, what is the highest population density in ANY census tract in the United States? (2) per square mile.

3. According to the map and legend, what city other than Los Angeles, San Diego and San Francisco, has over a half million people. (3) .

Step 6. Look at the color scheme used to differentiate between regions with a high population density and a low population density. This color schema is a "color ramp" and is best used to show quantitative differences between regions or places. There can be quantitative differences between places as well. You should use a QUALITATIVE color scheme to map qualitatively different (or nominal) data. For example, if the people of states had to vote for their favorite soft drink and they could chose between Coke, Pepsi and 7-UP, it would be appropriate to make a map using Red, Blue and Green (qualitative scheme) to denote the statewide preference in soft drinks. Non-geographers who make maps frequently use the wrong color scheme, and communicate ineffectively their data.

Step 7. Answer the following question.

4: Fill in the blank: This map of US governors by party affiliation (click to see) is an example of: (4) color scheme.

Step 8. One problem with choropleth maps is that they frequently hide as much as they reveal. For example, the map of population density when you are zoomed out and can only see county-level patterns hides the differences in population density within counties. Too see how this problem works, zoom in on the city of Fresno (see screen capture 3 ). You should zoom in so that you can see individual tract numbers within Fresno (see screen capture 4 ). You can see there is much greater diversity of population density than the "zoomed out", county-level map suggests. If you were to mistakenly assume from looking at the county map that all the subdivisions within it were similar, you would be victim to the ecological fallacy, which happens when the nature of individuals (or subunits) are inferred by the characteristics of the larger group to which they belong. Make sure you remember that for a test or quiz.

Step 9. Try to estimate the population density in some of the highest density census tracts in Fresno. It's difficult isn't it? Two problems make it tough. One is the number of gradations of the orange-brown colors used. It's difficult to be sure what statistical category tracts like 13.02 and 54.03 lie within. Most people can only pick out 5 to 6 gradations of the same color easily. Luckily, this program allows you to get a "report" regarding any of the individual regions about which you are curious.

Step 10. To get a more precise estimation of the population density of any particular census tract, click on the "report" button at the top of the mapper window. (see screen capture 6) From the drop down menu in step 1, select "Comprehensive Report". In step two, where it prompts you to choose an area selection method, chose "Points" by clicking the radio button next to "Points". Click OK (see screen capture 7). Notice that your cursor will become a "cross hairs", like a large plus (+) sign.

Step 11. Place the cross hairs cursor somewhere in Census Tract 47.04 and click once. Repeat this with census tracts 25.01 and 13.02. Next click on the words "Make Report" in the "Report Help" dialog box on the right (see screen capture 8).

Step 12: Examine the statistics produced in the report window and answer the following questions.

5. Report the number of the selected tract has the highest population density? (13.02 or 25.01 or 47.04) (5) .

8. This number is a bit deceiving, so divide the total number of "Female head, no husband present families" in these three tracts by the total number of "Family Households" (3,927) and report the percent of all families living in a female headed household: (8) .

The same percentage for the rest of Fresno County is 20.65%, for all of California it is 18.29% and for the entire United States it is 17.97. You can tell that these neighborhoods have a larger percent of female headed households than the county, state and national averages.

Very Important!! - Though you will find that these census tracts are 1) crowded, 2) more than half of a certain ethnicity, 3) have a larger percentage of families without a husband around, you can not assume that any family with one set of characteristics also have another. It is possible that the dominant ethnicity in this neighborhood may have a very low percent of families without a husband. However, you can say that in folks that have these characteristics do live in the same region and very well may be one in the same.

Part II: Making a Dot Density Map and Slide Show

Another means to show data on a map that is useful is the dot density map. This type of map has some advantages and disadvantages. The main problem for most students seems to be the misinterpretation of the placement of the dots. The dots are placed randomly within a territory (like a county or census tract), so you can not assume that the dot is at the exact location that whatever it is representing is. Another problem is students assume that each dot represents one person, but they generally represent a number of people, so you'll have to check the legend to see what a single dot represents.

A more complete list of dot density map pros and cons is available at the link : http://go.owu.edu/~jbkrygie/krygier_html/geog_353/geog_353_lo/geog_353_lo12.html

The Social Explorer mapping program uses dot density maps to show the distribution of people in several data sets, one of which is the distribution of the ancestry of Californians. You will map several of these and make a slide show of these distributions. These maps or similar exercises may be useful for teachers in the lower grades who frequently do units on pupil ancestry.

Step 13. Zoom Out so you can see the outline of all of California, but not much of Oregon and Mexico. Select from the drop down menus under "Choose a map:" Leave the uppermost selection box to 2000 Census Tract, but click the down arrow in the middle selection box to reveal a list of choices. Select Ancestry from the list. (see screen capture 9) . The default "ancestry" is "single ancestry", which isn't very interesting, so replace that category with "multiple ancestry", from the same drop down box list. What is really strange is that more people pick a single ancestry, when the vast majority of American families have ancestors from multiple ethnic groups, if not multiple continents. What this suggests is that people have a less complex understanding of their own ancestry.

Step 13. From the list of ancestry options (the third box) select German. It may take a moment to make the map. Note that each dot should represent 10 persons. German is supposed to be the most common ancestry in the United States, so we'll use that as a measure against which a comparison can be made with the distribution of other ethnic groups in the California.

Step 14. Click on the "create a slideshow" button in the lower right corner of the mapper window. A new tool bar of sorts will open across the bottom of the mapping program containing a row of squares with the words "click here to save current map". Chose the left most square and click in it to place a copy of the German ancestry map in that window (see screen capture 10).

Step 15. Next select from the list of ancestry "Italian". In the next square next to the map of Germans, click once to place this map of Italians, so that you have two maps in your slide show. Repeat the process and add another three European, African or Arabic ancestry categories to your map and slide show.

Step 16. In order to see either the map of Asian-Americans or Spanish speaking Americans you have to go back to the "Choose a Map" options and pick from the middle drop down list "Asian and Hispanic Groups" (see screen capture 11). The default map produced is a dot density map of "Asian", which is a very broad category and each dot represents 1,000 people. Don't select that for your slideshow, but instead, select from the list of Asians and Hispanics "Chinese", and add Chinese-Americans to your slide show. Next, select from the list of Asians Hmong (pronounced generally in America as "mong" or "mung") and add this map to your slide show. Next, select Mexican and add that map to your slide show. Select two or three other groups you'd like and add them to your slide show.

Step 17. Once you have at least 10 maps in your slide show, press the play button (like a triangle in a circle) in the slide show tool area in the lower right corner of the mapping program. The maps should then begin to appear in the main map window, starting with the map of Germans and Italians. You may chose to slow the animation down by sliding the little square on the speed control mechanism in the mapping tools window toward the left. You may also want to pause it occasionally.

I don't believe you can save the slideshow unless you have a subscription.

Step 18: Recall the locations of the major cities and rural-agricultural regions in California and answer the following questions:

9. Of the ethnic group maps in your slide show, which group stands out as the most exclusively concentrate in the Great Central Valley? (9)

10. Of the groups you mapped, which appears to be most heavily concentrated around urban areas? (10) .

Part III: Employment Patterns in California.

Step 19. Zoom out so you have again the map of California as a whole. Select from the list of variable categories (middle list) Industry. From the list of industry variables, chose "%Agricult/Forest/Fish/Hunt/Mine", which means "percent of workers engaged in Agriculture, Forestry, Fishing, Hunting or Mining". Make a "report" and select only the county that shows up darkest on your map of California counties. You may have to zoom in a bit on the county you chose. Examine the table produced and answer the following questions:

11. Which California county has the highest percentage of its workers in this category? (11)

It is worth noting that this county does not have any significant city and though the total number of agricultural workers is not impressive, the lack of a city makes this county both very rural and mostly agricultural.

Step 20. Repeat the process, but this time make a map of the percent of people living in poverty at the county level. Answer the following question.

13. What is the name of the region where the largest group of counties with a high poverty rate? (13)

Note that you can make a variety of maps using a large number of variables.

Part IV: Ethnic Change in Los Angeles

The last part of this exercise focuses upon demographic change in Los Angeles since World War II. This is a subject concern in the California State Standards, so it seems worthwhile to spend a moment on the topic using this tool.

Step 21. In the very top toolbar, above the mapper, click on the word "Maps" to take you back to the Interactive Census Maps home page. Next, click on the link "Los Angeles County - 1940-2000: Race Map" . This opens a mapper focused just on Los Angeles County. Your task is to build a slideshow depicting the changes in Hispanic population patterns in L.A. County since 1940. You may want to zoom in a bit, to eliminate the large, but sparsely populated census tracts in the northern part of L.A. County. Start with the "LA County 1940" / "% Hispanic" map, place it in the first box in the slideshow and repeat that for every decade to 2000. Start the slide show and pay close attention to the changes that occur. Answer the following questions.

14. In 1940, what was the maximum percent of Hispanics in any census tract? (14)

15. There are two neighborhoods in the San Fernando Valley that had an above average percentage of Hispanics in 1940. Name one. (15)

16. In 2000, what neighborhood in the San Fernando Valley is the center of the largest cluster of very high percent Hispanic census tracts? (16)

17. Examine closely the changes between 1940 and 1950. What appears to be happening during the decade following World War II?

Answer 17

When you click the button below, you will be directed to a web page that shows your answers. The instructor will get a copy of this email as well, but you may want to keep a copy for your records. If you are curious about the correct answers, please bring your questions to class