Release the control key and then right click on the center of either data frame. From the ... Lock your all layers except the 'text' layer by clicking into the empty box ...
GIS LAB 3
DOWNLOADING AND JOINING CENSUS DATA—
Los Angeles County Transit
Overview In this lab, you will: Download American Community Survey and shapefile data Manage Excel spreadsheets into a usable format Join data to a shapefile Create a comparison layout This lab has no prepared files! You will create all the necessary shapefiles from scratch. Please remember to use Mozilla FireFox! Sometimes, Internet Explorer cuts off census data during the downloading process. Recommended Reading • Overview of tables and attribute information If link does not work see: ESRI 10 Help Data Support in ArcGIS > Tables and Attribute Information > Understanding Tables and Attribute Information > An Overview of Tables and Attribute Information American Community Survey Data Users Guide Dataset Comparison American Community Survey Data Description
PART I: PRELIMINARIES
Save all the files to your lab3 folder.
In this lab, we will compare Median Household Income with the Percent Transit Users in the Los Angeles County census tracts by using the American Community Survey 5 year estimate data. First, we have to specify the geographical area we are examining, and then we have to specify data tables we want to process. 1. From the Census Webpage, click Geography > TIGER Page > TIGER/Line Shapefiles & Files > 2011 TIGER/Line Shapefiles Main Page > Web Interface. 2. Under Select a layer type choose “Census Tracts” and click “Submit”. On the next screen, choose “California” and click “Download”. 3. The LA County boundary file isn’t yet available via Census, so return to the ESRI Webpage. Click the state of California on the map, choose “Los Angeles” from the Select by County dropbox and click “Submit Selection”. We want the County 2000 file. Luckily, the county boundaries haven’t changed since 2000. 4. Copy the zip files you downloaded and paste them into your lab 3 folder in your H: drive. 5. Unzip the files by right clicking and select extract. 6. Then unzip the resulting zip file by right clicking and selecting extract. 7. Open ArcCatolog. 8. Rename the shapefile tl_2011_06_tract to caliTracts by right clicking on the file name. Rename at_tigeresri… laCounty. 9. Set the coordinate system using ArcCatalog. (same process as last week) 10. Navigate to the Census Tract 2010 shapefile that you just downloaded for California in your lab 3 folder. Right click on it: Properties and then under the Details box click on Select > Geographic Coordinate Systems > North America > NAD 1983.prj.
2006-2010 American Community Survey Data
1. Go to the class links page and select the American Fact Finder link. Or American fact finder [pic] 2. Click on “Geographies” on the left. (The 2006-2010 5-year estimates have information for all states and territories. The 3 year estimate only has information for geographic areas with populations of 20,000 or more.) 3. In the Geography Filter Options drop-down menu, select “Census tract”. 4. The Geography Results box presents all census tracts by state but we only want LA county. In the Within State dropdown menu, select “California”. 5. Scroll down in the results window and select “All Census Tracts Within Los Angeles County”. 6. You can now close the Geographies selection window. 7. The number of tables to examine is huge. This is especially true of the American Community Survey data which has a great deal more categories than the Census. You can use the Topics menu to search for specific characteristics. For this lab, we’ll be looking at Median Household Income and Means of Transportation. The coded number for Mean of Transportation is B08301 Means of transportation to work. Type B08301 into the Search box and click “GO”. (Take your time looking through the list and think about how you can use census data in your midterm project) 8. In the Search Results window, check the box next to Means of Transportation to Work for 2010. You can click “View” to see an example of the data. Click “Back to Search” at the top-left of the page to return to the results screen. With the 2010 box checked, click “Download” to get the resulting zip file. 9. Repeat 7 & 8 for B19013 Median household income (in the past 12 months in 2010 inflation-adjusted dollars). Remember to remove the “B08301” criterion from Your Selections at the top-left.
FORMATING DATA IN EXCEL
1. Navigate to the newly downloaded zip file. 2. Extract it into your lab 3 folder (right click and “extract here”—you will get three files – one Excel and two Text) 3. Open the ACS_10_5YR_B08301 Excel file. 4. We will keep this original downloaded version to use as a coded reference. Remember to use the save-as option so that you do not overwrite the downloaded file. Rename the file “laTractsTrans.xls” and save it in your Lab3 folder. [pic] Rename the variables as listed below (Use Row 6. We are going to remove the top five rows before opening the data in ArcGIS but they’re handy for now. The first example has the cell to rename first): ▪ (VD01:HD01, Cell Column D) Total: Rename to “TotlWrkrs” ▪ (Column H) Car, truck, or van: Drove alone: Rename to “SoloDriving” ▪ (Column J) Car, truck, or van: Carpooled: “Carpool” ▪ (Column V) Public transportation (excluding taxicab): “PubTranst” ▪ (Column AL) Bicycle: “Bike” ▪ (Column AO) Walked: “Walk” 1. We can clean up this file by deleting some of the rows and columns we won’t use. Start by deleting rows 1-5 and 7, which we MUST do for the data to open correctly in Arc. Also remove the “.” and any other special characters (remember you can only use letters, numbers, and underscores). You may also delete the transportation variables we didn’t rename, but keep the identifiers in the first few columns. 2. The first two columns contain geographic identifiers, but notice that “GEO.id2” is missing a leading “0”, which we’ll need to match this data with our census tracts. To remedy this issue, Insert a new column by right-clicking on Column C and selecting “Insert”. 3. Name the column “GEOid3”. To populate it highlight column A, select the “Data” menu from the top toolbar, and click “Text to Columns”. [pic] 4. Make sure the Delimited radio button is selected and click “Next”. 5. In the Delimiters options check “Other” and type “S”. You should now see that the right column under Data preview parses out a proper FIPS code. Click “Next” and you’ll arrive at the last step. 6. We don’t need the left column that is highlighted in the Data preview so select “Do not import column (skip)”. Select the right column in Data preview and select ”Text” for the Column data format. Lastly, set the Destination to “C1” and click ”Finish”. 7. The new column now contains the leading zero that we’ll need to match to our census tract data. You may need to re-enter the column heading. 8. You can delete column B (GEOid2) if you wish. Be sure to save as to avoid overwriting the original copy and close the workbook. 9. Repeat the process for the Median Income file (there are far fewer variables to deal with) and save as “laTractsInc.xls”. (Column D): Median household income in last 12 months: “MedInc”.
Note: In Arc GIS 10, Excel files (.xls and .xlsx) work instantly. Other types of files may need to be converted to .dbf (DBASE IV) files.
OPEN ARCGIS AND ADD DATA TO THE MAP
PART I: JOINING DATA
Open ArcMap 10.
Save your project as “YourUCLAID_Lab3” in your Lab3 folder (REMEMBER TO SAVE EARLY AND OFTEN)
1. Add the California Census Tract shapefile that you downloaded. Each census tract-shape has a designated number. Right click on the caliTracts shapefile and click on Open Attributes to see the table of geographical data.
2. We only need census tracts for LA County instead of California as a whole so add your LA County shapefile and perform a clip (Geoprocessing > Clip with caliTracts as your Input Feature and laCounty as your Clip Feature).
3. Add the laTractsInc.xls and laTractsTrans.xls tables.
4. Right click on the laTractsTrans spreadsheet and click on Open to see the table of data (Shortcut: When the layer is highlighted, press CTL + T to open the attribute table)
5. Compare the tables.
Look at the unique geographic code used to identify each of the census tracts in Los Angeles County (GEOID). If you compare this to the laTractsTrans spreadsheet, you will realize that these numbers correspond to the GEOid3 column.
1. We are ready to join the Median Income and Means of Transportation data to our shapefiles. Right click on the laTracts shapefile. Roll your cursor over “Joins and Relates” and click on “Join…” 2. A Join Data window will open. In the first drop down box (“What do you want to join to this layer”), select “Join attributes from a table”. In the first field (“Choose the field in this layer that the join will be based on”), select “GEOID” from the dropdown menu. 3. In the second field (“Choose the table to join to this layer, or load the table from disk”), navigate to the laTractsInc file you just reformatted. 4. In the third field (“Choose the field in the table to base the join on”), select the name of the column you modified, it should be “GEOid3” Then click “OK.” 5. Now, the two tables have been fused together. The join is temporary. If you load the laTracts shapefile into another map, you will have to re- join to preserve the data structure. 6. Repeat steps 1-4 for the laTractsTrans table. 7. To save the new combined table, export the data as a new shapefile (right-click on the laTracts shapefile in the table of contents and data, then export data. Save as “laTractsDataJoined” in your Lab3 folder in your H: Drive. Note: After joining data to a shapefile you need to make sure the joint features from your spreadsheet are not null. If they are, your original spreadsheet needs further modification. You can read about this in an article in Esri forums: http://support.esri.com/index.cfm?fa=knowledgebase.techarticles.articleShow& d=31122 In order to redo your join make sure to remove the join first. (Right click on the shapefile. Scroll down to Joins and Relates>Remove Joins and click on the join that you just have made.)
PART II: Clipping the LA County Shapefile
1. Clip the laTractsDataJoined shapefile with the California boundary shapefile (caliDetail) from your Lab2 prepared files folder. You can also get the clip dialog from ArcToolbox [pic] > Analysis Tools > Extract > Clip. 2. Select an appropriate name for your output such as “laTractsDataClipped”. 3. From ArcMap, right click on laTractsDataClipped layer and select "Open Attribute Table." (You can see how the data that you joined earlier is still applied.
Displaying numbers as percentages 1. Select Properties of the laTractsDataClipped layer. 2. From the Symbology tab, select Quantities > Graduated colors. 3. Select PubTranst as the value field. Normalize the data by TotalWrkrs in order to represent your values as a percentage. This allows comparison between census tracts because it takes into consideration how many people are estimated to be working in each tract.
Classifying your data 1. Click the “Classify” button on the upper right. This Classification window will allow you to specify where you want the breaks in your display to occur. The default is “Natural Breaks” but this is determined by the computer. From the Method dropdown, there are other classifications such as “Equal Intervals,” and “Quantiles.” You can also determine the number of classes. Experiment but consider the nature of the data. For example, income data might be better displayed when classified based on quintile (i.e., what census tracts are in the bottom 20% of median income in LA County.) In another case, it might make more sense to look at Standard Deviation of income in each census tract. In general, it is best to choose the classification rather than rely on “Natural Breaks”. For a detailed breakdown of classification types, look at the Methods of Classification PDF on Week 3 from “GIS and the Urban Environment” 2. Click on the Labels header and then select Format labels [pic] 3. Switch the category to percentage. Select the second radio button which says “This number represents a fraction. Adjust it to show a percentage.” 4. Click numeric options and adjust the number of decimal places to 2 5. Select “OK” twice. Adjust the color ramp to your liking. 6. Click on the symbol header and select Properties for All Symbols. Change the outline color to “No Color” In the county wide-scale, removing the color outlines will help patterns/trends emerge in the data.
PART III: INSERTING A NEW DATA FRAME 1. Insert a new Data Frame (Insert > “Data Frame”) 2. Copy laTractsDataClipped and paste it into the New Data Frame. 3. Set the symbology for this layer to show the variation of median income among all the census tracts. In the symbology tab, set the value to “Med_Income” IMPORTANT: Use the same classification method and the same number of classes as the other data frame. 4. Format the labels as currency
PART IV: CREATING A LAYOUT
1. From the View menu, choose "Layout View." A layout toolbar should appear, and your screen shot will show your map in the middle of a piece of paper. 2. Today, we will create a comparison layout, showing two identically scaled maps side by side representing different data. 3. Take one of your data frames and size it (select a size that will allow you to place the two data frames side by side) to your liking. 4. Make the second data frame the same size as the first data frame (the one that you completed to your liking) by left clicking on the second data frame and then press and hold the control key while left clicking on the first data frame (the one that you completed to your liking). Release the control key and then right click on the center of either data frame. From the menu that opens, move your mouse over “distribute” and then click on “make the same size”.
Note: When you have both data frames selected, one will be outlined in turquoise (the second one you selected) and the other will be outlined in green (the first one you selected). The data frame outlined in turquoise will be the data frame to which the other frame is sized.
5. In order to make the maps the same ratio you need to have one of the maps zoomed into the distance you want. Now select that frame. Go to the Bookmarks option on the toolbar. Select the “create” option. You can change the title if you want, but you can leave it as “Bookmark 1” 6. Now select bookmarks from the toolbar again. This time select “Manage”. Choose the save option on the right hand side and choose “save selected”. Navigate to your lab 3 folder in you H: drive and save the bookmark there. Then click close 7. Now select the other data frame. 8. Click on the bookmarks option again on the toolbar and choose the manage option. Select “load” and navigate to the bookmark that you created. 9. Now the two data frames are at the same ratio and extent. 10. Position the two data frames side by side (one on the right and one on the left) and position them so that the tops and bottoms of the frames are aligned. To align the tops and bottoms, left click on the first data frame and then press and hold the control key while clicking on the second data frame. Release the control key and then right click on the center of either data frame. From the menu, move your mouse over “align” and then click on “align top”. (You may also choose to position the frames up and down, i.e. one vertically below the other, and then align the right and left sides of the data frame by selecting “align left” from the “align” menu). 11. Remember to add a scale bar. If both maps are identically scaled, then you need only one scale bar, but two legends. We will add the source information, north arrow and your name in Illustrator.
12. Save your map and go to File > Export Map. Save file as “YourUCLAIDLab3” and within the “Save as type” drop down menu select “AI”
Create a Layout
1. Start Adobe Illustrator. (If you do not see the icon for the program on your desktop it is located within the folder “Adobe Design Premium CS5” folder. 2. Open the AI file you just exported 3. Your tool bar should already be on your screen. If you do not have a tool bar that appears like the one to the left, go to “Window” and select “Tools” 4. Now we need to bring up the Layers menu. Go to the “Window” tab at the top of your screen and then click on “Layers”. (Shortcut: F7) This menu should show up on your screen: [pic] 7. Your layers from GIS should show up within the Layer Menu. We need to add text, so to keep things organized, we need to create a new ‘Text Layer’. Create a new layer by clicking on the pull down menu that is circled in red in the image above. Select “New Layer” and when prompted, name your layer Legend ‘Text’. 8. If you want to rename any of your layers, double click on the layer’s name and rename the layer. 9. Look through the list of layers and make sure you do not see any ‘lock’ symbols. If any appear, click the lock symbol until you see none. 10. Now, using the black arrow in the tool bar select your image layer and scale it to the desired size on your page. (Hold shift while you are scaling your image so it scales proportionally). 11. Lock your all layers except the ‘text’ layer by clicking into the empty box immediately next to each layer’s name. The small lock should appear to indicate that the layers are locked. 12. Select the Text layer. You will know it is selected if it is highlighted in blue (this indicates that the text you are about to create will be created within that layer) 13. Select the “T” symbol in the tool bar and click and drag your mouse within your paper space. A rectangle should appear with a blinking cursor.
14. Name your map and move the text to its proper location. 15. Use the text tool to name your Sources and add text to your legend and to add any additional labels you want. You can manipulate the text properties at the top of your screen. If you do not see the text attributes at the top of your screen go to Window>Type>Character and a window will appear on your screen allowing you to manipulate your text. 16. To create a north arrow select the line or pen tool in your tool bar and draw a line within your paper space. 18. Now we need to open the Stroke menu to add the arrowhead. Go to Window>Stroke and you should see this menu: [pic] 19. Next to “Arrowheads” select the arrow head you desire. 20. In order to make sure everything is neat and lines up, you will need to turn on your ruler and grid background. Go to View>Show Grid, then View>Snap to Grid. 21. You may need to change the transparency of your “Image” layer to see the grid behind. To do this, select and unlock the “Image” layer. Select the image and at the top of your screen next to “Opacity” type in 50. [pic] 22. Now use the grid to drag each of your elements into place. 23. Play around with the other items in the tool bar and the list of tools under the “Window” at the top of your screen until you are satisfied with the image. 24. Export as a jpeg when you are finished and post to CCLE.
Export the map as a JPG named YourUCLAID_Lab3.jpg on your H: Drive Post to the website.
----------------------- This is aligned to the right. This means excel believes this is a number
Notice this is aligned to the left. This means excel believes this is text