Effective Spatial Planning of Watchtowers for the Detection of Wildfire Hotspots in Thasos Island, Greece

Forest fires, beyond the obvious ecological role that plays in forest ecosystems, can be a detrimental factor to natural and human ecosystems downgrading the quality of life of local population. The paper aims to enhance forest fire prevention through the prompt detection of fire events, a fact that would immediately alarm the firefighting forces to contain and mitigate the severity of this phenomenon. To this end, viewshed analysis has been implemented taking into consideration multiple factors: the overlapping effect minimization; the visibility maximization with a certain number of observatories; the sufficient visibility of certain land cover types. The results indicate the selection of four groups of observatories (each group covered a sufficient percentage of visibility) covering almost 70% of the entire island which is considered a satisfying figure given the rough topography of the study area. Aher these first 20 positions, the incorporation of extra locations would provide marginal profit in visibility terms. Therefore, the selection of the number of groups of observatories is mainly a political decision weighting the interaction of environmental protection and financial restrictions.