Error assessment for a provincial timber inventory

Abstract

In this case study of the Saskatchewan provincial timber inventory, the major sources of errors were identified and suitable procedures presented for their estimation. Applying those procedures on a pilot area, the results showed that sampling error was by far the most important component affecting the accuracy of volume estimates. Variances arising from the use of taper functions to estimate tree volumes were under 0.05%, and variances from 3P subsampling were about 3% of the total variance. A computer simulation experiment showed that a 2% measurement bias in both diameter and height measurements may result in 8% bias in the volume estimate. Key words: 3P sampling, taper functions, error budget