working with CHGIS data in ARCVIEW

How to open GIS files

How to search GIS files

How to export attributes to tables

How to join tables to existing GIS tables

How to create thematic maps based on attributes

How to generate Thiessen polygons from points

How to Open Files

How to Search

To search for a keyword or value in ArcView shapefiles use a SQL query, found in the THEME | QUERY menu.

How to EXPORT

If you want to export an entire ArcView shapefile or a selection of one, including spatial data use THEME | CONVERT TO SHAPEFILE.

  • add THEME to a VIEW in an ArcView project.
  • use QUERY from the THEME menu described above, or SELECTION TOOL to choose a subset of the THEME, if desired
  • if you have defined a selection, only the selected records will be converted, if no records are selected then the entire Shapefile will be saved as a new copy
  • from the THEME menu, select CONVERT TO SHAPEFILE
  • Enter the NEW Filename on the left-hand side of the dialog box
  • click through the directory on the right-hand side to find the desired folder where the new Shapefile will be saved
  • click OK button to save the new Shapefile

If you want to export the attributes for an entire ArcView shapefile or a selection of one, NOT including spatial data use FILE | EXPORT.

  • add THEME to a VIEW in an ArcView project.
  • use QUERY from the THEME menu described above, or SELECTION TOOL to choose a subset of the THEME, if desired
  • if you have defined a selection, only the selected records will be Exported, if no records are selected then the attributes for the entire Shapefile will be exported
  • open the ATTRIBUTE TABLE for the THEME
  • from the FILE menu, select EXPORT
  • choose the export table format (note: Chinese Characters may be lost in ArcView 3.x unless you are either (a) exporting to delimited text on a Chinese native operating system, or (b) you are using Windows 2000 with the correct locale, language, and editing/proofing configurations enabled)
  • Enter the NEW Filename on the left-hand side of the dialog box
  • click through the directory on the right-hand side to find the desired folder where the new Export File will be saved
  • enter the name of the new export file in the "File name" box
  • click OK button to save the new Export File

How to JOIN

If you want to join your own attribute values to existing ArcView shapefiles or a selection of one, first export the ATTRIBUTES following the steps outlined in the EXPORT section above. Be sure that the exported file contains a UNIQUE ID # for each of the records that you will be joining back to the original table. If you exported the attributes as a Delimited TEXT file, open the file in your preferred spreadsheet or database software and add a new column for each NEW CATEGORY of data values to be added. For instance, a POPULATION column, a GRAIN TAX column, etc. Then fill in the correct values for each record in those columns. Once you have finished the addition of your data, DELETE the unnecessary COLUMNS, but be sure to preserve the column containing the unique ID #s. With your trimmed down dataset, use the TABLE JOIN function in ArcView described below.

  • add the existing THEME that you want to join with your new data file in ArcView (NOTE: highly recommended to use a COPY of the shapefile and keep the original for future use)
  • make the PROJECT window active
  • select ADD TABLE from the PROJECT menu
  • select the file format of the table to be added from the drop-down list
  • navigate to the folder where your new data file is located
  • click OK button
  • when the table to be added is open in ArcView as an attribute table, click on the column heading that contains the unique id #s to be joined on
  • activate the THEME
  • open the attribute table of the THEME to be joined with, and click on the column heading that contains the unique id #s to be joined on
  • if the two columns selected are able to be joined, the TABLE JOIN button will be enabled:
  • hit the TABLE JOIN button
  • if the two columns selected are NOT able to be joined, the TABLE JOIN button will be grayed out. this can happen for various reasons, such as: the data types of the two columns is not the same, the imported table is delimited in a way that ArcView does not support, etc.
  • if the join was successful, the new columns will now be included in the attribute table of the THEME, appended to the right hand side
  • NOTE: return to the THEME VIEW and select THEME | CONVERT TO SHAPEFILE in order to save your newly JOINED table as a new file

Thematic Maps

If you want to create a thematic (chloropleth) map of polygons, lines or points, using a range of colors to represent different values in the attributes table of a Shapefile in ArcView, use THEME | EDIT LEGEND. Note: you must first join the table containing numeric values in a specific field to the attribute table of the shapefile that you want to represent as a chloropleth map, as described in the JOIN section above.

  • add the THEME to be mapped thematically ArcView
  • select EDIT LEGEND from the THEME menu
  • select the method of display (such as graduated colors for polygons, or dot for points from the list in the "Legend Type" box.
  • choose the FIELD that contains the VALUES to be mapped from the list in the "Classification Field" box.
  • a auto-selected range of colors (usually based on five Natural Breaks) will appear below
  • select the name of a second FIELD to normalize the values in the first field in the "Normalize By" box (if desired)
  • hit the CLASSIFY button if you want to change the statistical method from Natural Breaks to Quintiles, Equal Intervals, or other method, and to choose the NUMBER of gradation levels
  • hit OK button
  • select the desired color scheme from the list in the "Color Ramp" box.
  • hit APPLY button
  • NOTE: the results of thematic maps are often misleading due to the calculation of raw values without taking into account the AREA or the DISTRIBUTION of those values across the total area occupied by a polygon feature in GIS. Those wishing to pursue thematic mapping are strongly advised to first read the following books:
    "How to Lie With Maps" by Mark Monmonier
    "How to Lie With Statistics" by Darrell Huff
    "Mapping Information" Howard T. Fisher

How to Generate Thiessen Polygons from Points

ArcView

CHGIS provides county level points but not county level polygons for all of China. If you would like to assocate county level data to polygons to use Thematic Mapping, described above, you can use the County Points, and an encircling polygon to generate Thiessen Polygons around each point. Thiessen Polygons essentially enclose the space around each point so that the space the polygon created encompasses all the space that lies less than half-way between the Thiessen polygon center point and any other Thiessen polygon center point. To do this, we have included an ArcView extension on this CD-ROM with the permission of the author, Francisco Olivera.

  • first add the CRWR file to your ArcView Extensions folder as described on the page above.
  • open the extension by selecting CRWR-Vector from the FILE | EXTENSIONS menu
  • open a polygon layer and select a single polygon that you wish to be the outer limit of your Thiessen Polygons. In this example we choose the area of Tibet using the SELECT TOOL:
  • the area of the selected polygon should be colored yellow:
  • select CONVERT TO SHAPEFILE from the THEME menu
  • choose a folder and filename to keep your outer polygon file
  • when prompted to add new theme to view choose YES
  • DELETE the original theme from the view
  • zoom in on the new TIBET theme
  • add the COUNTY POINTS theme (CCAP_PTS)
  • choose THIESSEN POLYGONS from the CRWR-Vector Menu
  • you will be prompted to select the FIELD in the points file to use as the link to the Polygons. Select SYSTEM_ID:
  • you will be prompted to select the polygon theme to use as the outer boundary. Select your Tibet THEME from the list:
  • you will be prompted to continue by discarding all the point features that lie OUTSIDE the Tibet polygon. his YES to continue:
  • you will be prompted to choose a new name for the output Thiessen polygons file. hit OKAY
  • the new Thiessen polygon file should display on your View.
  • now you can join your data to the Thiessen polygons and create thematic maps: