Palladino Spring 2014 Geography 26 Lab Exercise #2 Your Name: ANSWERS I. Data Classification We will use the Symbolization tab for the Census Block Groups layer to create various presentations of the census data for Ventura County based on different classification schemes. Use the ArcMap shortcut or the START menu path to start ArcMap. Open Lab2.mxd. Zoom to the Bookmark: Ventura Mainland. [Hint: If there is a red ! before the name of a layer, you will need to help the program reconnect to the layer. Double-click the layer name, choose Source, then click on Repair Data Source and help the program find the data set. Note that most of these are layer files (.lyr) which in this case have names that are the same as their source data.] Change the name of the Layers data frame to Population Density. Add the Ventura_Block_Groups layer (.lyr) theme to the Population Density data frame. Move this layer right above the County_Boundary layer. Change the name of this layer to just Block Groups. Add the VTCITIES layer (shapefile) from your Lab 1 Data folder. Rename this layer, City Areas, and change its symbology so that it has no fill and a border that stands out (say 2 point width). It should be moved above the Block Groups layer. Save this as a .lyr file. Use the Symbology Tab in Block Groups properties to make a graduated color map. Accept the default values for this first map. Turn the extra layers off so you can see your Population Density map. 1a. What classification (value) field will you need to use to make this map? Pop00 SQMI 1b. If you didn’t already have a population density field, which fields could you use to obtain the same result? Value: POP2000 Normalization: AREA 1c. What is the default classification method and number of classes? Method: Natural Breaks Classes: 5 1d. What is the default color ramp? [Hint: right click on color ramp to help find name] Yellow-Dark Red (yours may vary) Now experiment with number of classes (but not too many!) Find a number of classes that appears to produce a map that clarifies the patterns. 2a. How many classes did you pick? (Answers will vary) 2b. What color ramp did you prefer? (Answers will vary) 2c. Describe the pattern of population density that you see on the map (i.e., Where is it high? Where is it low? Be specific.) [Hint: Label features on the City Area layer.] (Answers will vary) Geography 26 Page 2 Lab Exercise 2 [SAVE your map Document.] Insert a new map (Data Frame). Title it, “Quantile Classification”. Add the Ventura_Block_Groups and South_County_Extent layer files (.lyr) to this frame. [Hint: you can use the “Extent” layer to help you “zoom to layer”, since your bookmark for South County did not carry over from the Population Density map frame.] Using the same number of classes and color ramp from Question 2, create a population density map using the Quantile method. 3. Describe the differences in pattern that you see on this map [Hint: Use Layout View to see the two map frames side-by-side and to toggle between Data View for each frame.] (Answers will vary) [SAVE your map Document.] Insert another map (Data Frame). Title it, “Equal Interval Classification”. Add the Ventura_Block_Groups and South_County_Extent layers Using the same number of classes and color ramp from Question 2, create a population density map using the Equal Interval method. 4. Describe the differences in pattern that you see on this map. (Answers will vary) [SAVE your map Document.] Insert yet another map (Data Frame). Title it, “Manual Classification”. Add the Ventura_Block_Groups and South_County_Extent layers. Using the same number of classes and, create a population density map using the Manual method. Adjust the class breaks. 5a. Where are your class breaks? (Answers will vary) 5b. Describe the differences in pattern that you see on this map. (Answers will vary) [SAVE your map Document.] 6. Which classification scheme seemed to best represent the data (in your opinion?) Why? (Answers will vary) Geography 26 II. Projections and Coordinate Systems. Page 3 Lab Exercise 2 Insert a new data frame. Add the Streams, Major Roads, and County Boundaries layer files (.lyr) Use the Data Frames Properties dialog box to pick a new coordinate system. (use Predefined: PCS: UTM: NAD 1983:Zone 11N [Hint: you may have to scroll down to find this one. Also say “Yes” to the warning dialog boxes.]) 7. How does this projection change the shape of the county compared to the county boundaries in the Population Density data frame? [Hint: Turn on only the same three layers in that data frame. You may want to use the Layout view to see these maps side-by-side.] Makes it taller and more narrow. [SAVE your map Document.] EXTRA CREDIT Make another map frame, use the same layers as #7 above, but this time use the State Plane coordinates in NAD 1983 (US Feet), California Zone V. EX. 1. How does this map differ from the one in #7. [Hint you will have to look very close. Try overlapping the two maps in the Layout View.] Slight rotation (Anchor a point on the perimeter of both maps and make the overlying map transparent, if you zoom in to a corner point away from where you anchored the maps, and you should see the rotation if you zoon way in). Feel free to experiment with other projections.