e-ISSN 1828-1427 |
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Rivista trimestrale di Sanità
Pubblica Veterinaria edita dall'Istituto Zooprofilattico Sperimentale
dell'Abruzzo e del Molise G.
Caporale'
A quarterly journal devoted to veterinary public health, veterinary science and medicine published by the Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise ‘G. Caporale’ in Teramo, Italy |
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ISSUES ONLINE
2007
- Volume 43 (3)
July-September |
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Hélène
Guis, Annelise Tran, Frédéric Mauny, Thierry Baldet,
Bruno Barragué, Guillaume Gerbier, Jean-Francois Viel, Francois
Roger & Stéphane de La Rocque |
A
multiple fine-scale satellite-derived landscape approach: example
of bluetongue modelling in Corsica |
699-707 |
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Summary
Landscape ecology is seldom used in epidemiology.
The aim of this study is to assess the possible improvements that
can be derived from the use of landscape approaches on several scales
when exploring local differences in disease distribution, using bluetongue
(BT) in Corsica as an example. The environment of BT-free and BT-infected
sheep farms is described on a fine scale, using high resolution satellite
images and a digital elevation model. Land-coverage is characterised
by classifying the satellite image. Landscape metrics are calculated
to quantify the number, diversity, length of edge and connectance
of vegetation patches. The environment is described for three sizes
of buffers around the farms. The models are tested with and without
landscape metrics to see if such metrics improve the models. Internal
and external validation of the models is performed and the relative
impact of scale versus variables on the discriminatory ability of
the models is explored. Results show that for all scales and irrespective
of the number of parameters included, models with landscape metrics
perform better than those without. The 1-km buffer model combines
both the best scale of application and the best set of variables.
It has a good discriminating ability and good sensitivity and specificity.
Keywords
Bluetongue,
Corsica, Epidemiology, Geographic information system, Landscape,
Remote sensing.
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