how to create Thiessen polygons in ArcView
How to Generate Thiessen Polygons from Points

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 for Thematic Mapping, described above, you can use the County Points together with an encircling polygon to generate Thiessen Polygons. Thiessen Polygons essentially enclose the space around each point using an algorithm to calculate the location of a boundary mid-way between the available points. The resulting Thiessen polygons encompass 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, Prof. Francisco Olivera, Texas A & M University.

Linked below are some examples of Thiessen Polygons for Shanxi Province, using the CHGIS 1820 County Seats as the central points. After the Thiessen Polygons were created, statistics for Population and Changping Grain Quota were joined to the the counties and thematically mapped.