Environ Ecol Stat
DOI 10.1007/s10651-017-0378-y
Spatially-balanced sampling versus unbalanced
stratified sampling for assessing forest change:
evidences in favour of spatial balance
Maria Chiara Pagliarella
1
· Piermaria Corona
2
·
Lorenzo Fattorini
1
Received: 13 January 2017 / Revised: 20 March 2017
© Springer Science+Business Media, LLC 2017
Abstract Large-scale remote sensing-based inventories of forest cover are usually
carried out by combining unsupervised classifications of satellite pixels into forest/non
forest classes (map data) with subsequent time-consuming visual on-screen imagery
classification of a probabilistic sample of pixels taken as the ground truth (reference
data). In this paper the estimation of forest change from a sample of reference data
is approached by: (i) exploiting map data to construct strata in which changes are
occurred, and then adopting the stratified sampling joined with the HT estimator
with most sampling effort devoted to strata where changes are occurred irrespective
of their size, as suggested in most remote sensing literature regarding land change
assessments; (ii) adopting a spatial scheme ensuring spatially balanced samples, as
suggested in most recent statistical literature regarding spatial surveys, and exploiting
the map data in the difference estimator. The results of a comparison performed on
an artificial population of reference data generated from a real population of map
data recorded in Sardinia (Italy) discourage the use of unbalanced stratified samples
Handling Editor: Pierre Dutilleul.
B Maria Chiara Pagliarella
mariachiara.pagliarella@unisi.it
Piermaria Corona
piermaria.corona@crea.gov.it
Lorenzo Fattorini
lorenzo.fattorini@unisi.it
1
Department of Economic and Statistics, University of Siena, Piazza San Francesco, 7,
53110 Siena, Italy
2
Research Centre for Forestry and Wood, Consiglio per la ricerca in agricoltura e l’analisi
dell’economia agraria, Viale Santa Margherita, 80, 52100 Arezzo, Italy
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