Fine-scale mapping of vector habitats using very high resolution satellite imagery: a liver fluke case-study

The visualization of vector occurrence in space and time is an important aspect of studying vector-borne diseases. Detailed maps of possible vector habitats provide valuable information for the prediction of infection risk zones but are currently lacking for most parts of the world. Nonetheless, monitoring vector habitats from the finest scales up to farm level is of key importance to refine currently existing broad-scale infection risk models. Using Fasciola hepatica , a parasite liver fluke as a case in point, this study illustrates the potential of very high resolution (VHR) optical satelli... Mehr ...

Verfasser: Els De Roeck
Frieke Van Coillie
Robert De Wulf
Karen Soenen
Johannes Charlier
Jozef Vercruysse
Wouter Hantson
Els Ducheyne
Guy Hendrickx
Dokumenttyp: Artikel
Erscheinungsdatum: 2014
Reihe/Periodikum: Geospatial Health, Vol 8, Iss 3 (2014)
Verlag/Hrsg.: PAGEPress Publications
Schlagwörter: Fasciola hepatica / liver fluke / small water body mapping / object-based image analysis / Belgium / Geography (General) / G1-922
Sprache: Englisch
Permalink: https://search.fid-benelux.de/Record/base-28532358
Datenquelle: BASE; Originalkatalog
Powered By: BASE
Link(s) : https://doi.org/10.4081/gh.2014.296

The visualization of vector occurrence in space and time is an important aspect of studying vector-borne diseases. Detailed maps of possible vector habitats provide valuable information for the prediction of infection risk zones but are currently lacking for most parts of the world. Nonetheless, monitoring vector habitats from the finest scales up to farm level is of key importance to refine currently existing broad-scale infection risk models. Using Fasciola hepatica , a parasite liver fluke as a case in point, this study illustrates the potential of very high resolution (VHR) optical satellite imagery to efficiently and semi-automatically detect detailed vector habitats. A WorldView2 satellite image capable of <5m resolution was acquired in the spring of 2013 for the area around Bruges, Belgium, a region where dairy farms suffer from liver fluke infections transmitted by freshwater snails. The vector thrives in small water bodies (SWBs), such as ponds, ditches and other humid areas consisting of open water, aquatic vegetation and/or inundated grass. These water bodies can be as small as a few m2 and are most often not present on existing land cover maps because of their small size. We present a classification procedure based on object-based image analysis (OBIA) that proved valuable to detect SWBs at a fine scale in an operational and semi-automated way. The classification results were compared to field and other reference data such as existing broad-scale maps and expert knowledge. Overall, the SWB detection accuracy reached up to 87%. The resulting fine-scale SWB map can be used as input for spatial distribution modelling of the liver fluke snail vector to enable development of improved infection risk mapping and management advice adapted to specific, local farm situations.