Monitoring Water Bodies Using Sentinel-1 Imagery for the Effective and Sustainable Mosquito Larvae Control [Greece]

Surface water body maps are necessary input for effective and targeted mosquito larviciding actions, assisting in the prevention of outbreaks due to viruses transmitted to humans by mosquito carriers, such as the West Nile Virus. The aim of this study is to identify the optimum automated method for monitoring water bodies in rice fields and wetlands, capitalizing on the Sentinel-1 satellite mission. The methods tested were assessed against field data collected in northern Greece. The comparison of various methods showed that the Otsu Valley-emphasis thresholding image binarization technique is the one which provides the highest accuracy. At the end of the rice-growing season, the lower overall accuracy was due to the higher density of vegetation. The presence of vegetation, built-up areas, floating algae, salt-crust formations, and water depth are causes of water detection errors. The fully automated water monitoring tool and the associated water maps are intended to be used as input to the DSS of project WaMoS, together with other parameters affecting larvae presence, in order to improve the environmental sustainability and effectiveness of larvicide applications.