Lab 5: Using IDW and Kriging for Interpolation

Inverse-Distance Weighted






The map communicates precipitation amounts, in inches, across Idaho in a continuous, contour format. The interpolation method used for this map was the Inverse-Distance Weighted method.









Kriging Method






This map also communicates precipitation amounts, in inches, across Idaho in a continuous, contour format. The interpolation method used for this map, however, was the Inverse-Distance Weighted method.

Comparing the IDW method and the Kriging method from the map perspective, the IDW method appears to be more precise in its adherence to the control point values. This is reflected in the very specific shapes that the contour lines form. The Kriging method, however, appears to be much more generalized.

Comparing the IDW method and the Kriging method from the five evaluation criteria:

• Honoring control point data: The IDW method appears to be more accurate, but neither method is extremely precise.
• Correct at non-control points: Cross-validation of RMS values from each method reveal that the Kriging method yielded the lowest RMS value.
• Ability to handle discontinuities: Both methods appeared to perform equally well in this criteria.
• Execution time: The execution time was slightly higher for the Kriging method.
• Ease of understanding: The Kriging method was more difficult to understand than the IDW method because of the selection of an appropriate semivariogram.