Satellite images to combat avian flu

A worldwide outbreak of the deadly avian flu variant H5N1 began in 2003. In studying the spread of the disease, the main focus has been on the transmission of the virus by domestic poultry. Yali Siâs research has shown, however, that wild waterbirds also play a significant role in spreading the virus. Her research has revealed a strong correlation between the outbreak of the virus and the migration patterns of migratory waterbirds, over short as well as long distances.  Satellite imagesIn order to anticipate future outbreaks, it is important to be able to predict the sites at which wild waterbirds are likely to settle. Currently, there is only a very vague idea of how waterbirds migrate. Yali Si has, therefore, used field tests and satellite images to investigate which grasslands are more likely to attract wild waterbirds to feed. Her research showed that the quality of the grasslands plays an important part in determining whether the wild waterbirds will settle. The grass should not, for example, be too long or too old, as this makes grazing difficult and reduces the relative amount of nitrogen.  Risk mapsSatellite data can be used to create risk maps, which can then show the most popular areas for wild waterbirds and thus indicate where the risk of the spread of the avian flu virus is greatest. Yali Si demonstrated that this is a feasible method, but states that more research is needed to refine the methodology and the resulting risk maps.  Yali Si conducted her research under the supervision of Professor Andrew Skidmore, Professor Herbert Prins and Dr Tiejun Wang, in the Biodiversity in Fragmenting Landscape research group at the ITC faculty (Geo-Information Science and Earth Observation). The research was supported by the China Scholarship Council.