Sampling simulation on multi-source output forest maps - an application for small areas
Matti Katila 1 and Erkki Tomppo
Finnish Forest Research Institute
Unioninkatu 40 A, FIN-00170 Helsinki, Finland
Tel.: +358 10 2111 ; Fax: +358102112104
Systematic samples were simulated on multi-source National Forest Inventory (MS-NFI) output thematic forest maps obtained by k-nearest neighbours method (k-NN) for areas of 1 km2 and 100 km2 . The standard deviations based on the simulated sample means were used as estimates for the standard errors (SE) of the particular designs. The variables of interest were the mean tree stem volume (m3 /ha) and the volumes by tree species. The effect of the temporal and thematic accuracy of the forest maps was studied with respect to the precision of the SE estimates from simulations. The simulated SEs were validated against an independent field inventory data measured from three test sites of 1 km2 and seven sites of 100 km2 in Eastern Finland. The effect of the estimation parameters of k-NN method on the error estimates was also studied. The study showed that the Finnish MS-NFI thematic maps can be used to estimate sampling errors for systematic field sampling designs with a plot distances down to 75-100 m on areas of 1 km2 and larger.
Keywords: multi-source forest inventory, sample simulation, standard error, Landsat TM
In: Caetano, M. and Painho, M. (eds). Proceedings of the 7th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences, 5 – 7 July 2006, Lisboa, Instituto Geográfico Português