Examining spatial autocorrelation and directional variation using the Semivariogram/Covariance Cloud tool

Examining spatial structure allows you to investigate the existence of spatial autocorrelation of the sample data and explore whether there are any directional influences.

Pairs of points that are close together (to the left on the x-axis in the semivariogram) should be more alike (low on the y-axis) than those that are farther apart (moving to the right on the x-axis).

If the pairs of points in the semivariogram produce a horizontal straight line, there may be no spatial correlation in the data and it would be meaningless to interpolate the data.

Steps:

1. Click the point or polygon feature layer in the ArcMap table of contents that you want to explore.
2. Click the Geostatistical Analyst arrow on the Geostatistical Analyst toolbar, click Explore Data, then click Semivariogram/Covariance Cloud.