Matti Katila

Empirical errors of small area estimates from the multisource National Forest Inventory in Eastern Finland

Katila M. (2006). Empirical errors of small area estimates from the multisource National Forest Inventory in Eastern Finland. Silva Fennica vol. 40 no. 4 article id 324. https://doi.org/10.14214/sf.324

Abstract

The precision of multisource national forest inventory (MS-NFI) estimators and simple synthetic estimators based on NFI field data only was assessed employing an independent inventory data set of several small areas in Eastern Finland. There were seven test units of size 100 km² and three test units of size 1 km² for which a systematic field sampling was carried out. The ‘improved’ MS-NFI method yielded the most precise estimates for mean volume and mean volume of pine and spruce: relative root mean square errors (RMSE^*) were 5%, 12% and 15% for 100 km² test units and 13%, 27% and 40% for 1 km² test units respectively. The stratified MS-NFI method was best for broad-leaved volume estimation. Synthetic estimation based on the NFI9 field plots post-stratified with coarse scale forest variable maps from NFI8 resulted in RMSE^*s comparable to those of the ordinary MS-NFI in areas of 100 km² for mean volume and mean volume of pine and spruce. The amount of variation between the field inventory estimates for the test units explained by the MS-NFI estimators remained the same or increased when the size of the area increased from of 1 km² to 100 km² and up to 2000 km². The validation of the largest areas was made against the NFI9 field inventory estimates for groups of municipalities in the study area.

Keywords
k-nearest neighbours estimation; Landsat ETM ; multisource forest inventory; synthetic estimation

Received 27 January 2006 Accepted 8 August 2006 Published 31 December 2006

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