MapWindow GIS Workshop 06 January 2009, McCurtain County, Oklahoma EXERCISE 2

Transcription

1 MapWindow GIS Workshop 06 January 2009, McCurtain County, Oklahoma Participants: Government Agencies and Utilities EXERCISE 2 In this exercise, you will learn: A. To query specific attributes in the attribute table B. To create a new shapefile C. To add new fields D. To download a satellite image and display it in MapWindow E. To display GIS files in Google Earth A. Querying Specific Attributes in the Attribute Table From EXERCISE 1, we imported several layers as shown in the illustration below: Right click tl_2009_40089_place and click View Attribute Table Editor. (Alternatively, highlight tl_2009_40089_place and click the Attribute Table Editor tool.) Its attribute table is shown below. It shows the major towns and cities in McCurtain County. 1

2 Let s use the Query function to query Idabel and save it as another shapefile. Click Selection > Query. (Alternatively, click the Query tool.) The Querybuilder popup appears. Using the scroll bar, double click on NAME. Click Equal sign button double quotes.. Type Idabel in single or Click Execute button. The Idabel record is highlighted. The Idabel area boundary is also highlighted in the map. 2

3 (Alternatively, you can click on the first column (gray color) of the Idabel record line to highlight the Idabel record. This is the easiest way to select the Idabel record. However, if you have hundreds or thousands of records and if you have to choose multiple fields, the Querybuilder function comes in handy.) To de select the highlighted record, click Selection > Select None. B. Creating a New Shapefile Click Selection > Export Selected Features. Save the new shapefile as Idabel. Save it in the MapWinWorkshop folder. Click Yes to the question: Do you want to load the new shapefile? Now we have a new shapefile named Idabel in the Data Layers area. 3

4 Uncheck tl_2009_40089_mccurtain and tl_2009_40089_place. Zoom in on Idabel boundary. Right click Idabel > Zoom to Layer. It shows the extent of coverage of Idabel. Next, let s change its color. Double click on Idabel to open the Legend Editor. Make the following changes: Fill Color: Transparent (Hint: Click on Fill Color. Click the scroll arrow. Hit the Web tab. Click Transparent Outline Color: DarkOrange Line Width: 2 Show Fill: False 4

5 Close the Legend Editor Let s save our project thus far. In menu bar, click File > Save As. Save as Workshop_B2.mwprj in MapWinWorkshop folder. Click Save. Download and add the file called streets.shp. Download and add the file called PARCEL_Polygon. Drag Idabel above PARCEL_Polygon. Let s change the symbology of the parcels. Double click PARCEL_polygon to open its Legend Editor. 5

6 Use Fill Color: Gainsboro and Outline Color: Gray. Right click PARCEL_Polygon > Zoom to Layer. Click the Attribute Table Editor to look at the parcel records. 6

7 You should see that there are 30,719 records or parcels. Close the Attribute Table Editor. Uncheck street for now. Let s activate some plug ins. In Main Menu, click Plug ins > GIS Tools. Also activate Open Metadata Manager. The plug ins GIS Tools and Metadata Tools are now displayed in the menu bar and toolbar. Highlight PARCEL_Polygon. Using the Zoom In tool, draw a small box somewhere at the center of Idabel. You may use the Pan tool to move to nearby locations. 7

8 C. Adding New Fields Let s calculate the areas of parcels. Highlight PARCEL_Polygon. In main menu, click GIS Tools > Vector > Calculate Polygon Areas Use a loaded layer PARCEL_Polygon. Use a new field called AREA_sqft. Shapefile Units: feet. Area Units: Feet Squared. 8

9 Click Calculate. Click Done when finished. Also calculate area in square meters (AREA_sqm) and acres (AREA_ac). You should have the three new added fields. Specify a query. Sort the AREA_sqft field. Right click on the field name, then click Sort ASC or Sort Desc. How many square feet is the smallest parcel? ( ) How many square feet is the largest parcel? (3,836,444.58) You can also use the Statistics function to determine minimum and maximum values. Click File > Selection Undone. Close the Attribute Table Editor. Let s look at the metadata of a layer. Highlight tl_2009_40089_place. Click Metadata Tools > View Metadata for Current Layer. 9

10 Save the project. Click File > Exit. D. Downloading a satellite image and displaying it in MapWindow F rom Geospatial Datasets for McCurtain County ( under Imagery, download ortho_e1 1_s_ok089.sid. Save it in the MapWinWorkshop folder. (The file is 436MB, so it may take awhile to download.) Extract it to the folder with the same name that is automatically created. Add the ortho_e1 1_s_ok089.sid image to MapWindow. Click Open to see the image. You may have to drag the image layer below all the other layers. Change display settings of PARCEL_Polygon. Double click PARCEL_Polygon to open the Legend Editor. Use the following settings: Outline Color Cyan, Show Fill False. 10

11 Close the Legend Editor. You may use the Zoom In, Zoom Out, Zoom, and Pan tools to adjust the view accordingly. Right click ortho_e1 1_s_ok089.sid> Zoom to Layer to view its entire extent. Right click Idabel > Zoom to Layer. 11

12 Using the Zoom In tool, draw a small box somewhere at the center of Idabel. You may use the Pan tool to move to nearby locations. Click the Save tool to save your project. Click File > Exit to close MapWindow GIS. E. Displaying GIS files in Google Earth First, we need to install a plug in for MapWindow so we can display GIS files in Google Earth. Download the Shape2Earth MapWindow plug in from: shape2earth.com/shp2e.aspx. Follow instructions to download and install. (Or, download a similar software called Shp2kml 2.0. It is a shapefile to kml, stand alone converter. You can get it from: Open MapWindow GIS. Open Workshop_B2.mwprj. In Menu Bar, click Plug ins > Shape2Earth. The plug in Shape2Earth is now installed and shown in the menu bar. Click Idabel > Zoom to Layer. Click Shape2Earth > Export to KML 12

13 Click Run Unregistered. Fill in the blanks as shown in the Shape2Earth Evaluation window below. Use the default parameters. Cli ck the small Google Earth icon to save Idabel as kml file. Again, Shareware License Information window of Shape2Earth pops up. Click Run Unregistered. Save as Idabel.kml in MapWinWorkshop folder. Opening Google Earth First, download and install Google Earth if it s not in your computer. Go to: earth.html. In main menu, click File > Open 13

14 Open Idabel.kml. You should see the McCurtain parcels plotted in Google Earth. Save MapWindow project. Exit MapWindow. Now we have just learned how to query specific attributes in the attribute table, create a new shapefile, add new fields, download and display a satellite image, and display GIS files in Google Earth. END OF EXERCISE 2 14