Assessing economic damage of wildland–urban interface (WUI) fires using economic model and high-resolution Planet Labs satellites constellation images.

Wildland-urban interface (WUI), the area where wildland vegetation and urban buildings meet, is at a greater risk of fires to occur due to extended human activity. In recent years, there is an increase in reported cases of large WUI fires while this trend is likely to continue due to projected warming and ongoing urban expansion in many regions. Accurate information regarding the spatial distribution and level of damage (e.g. burnt severity) following WUI fires is therefore required to allocate economic resources and prioritizing proper treatment actions. Remote sensing has been a major tool in monitoring and assessing wildland fires. However, because of the trade-off between the spatial and temporal resolution of satellites images, monitoring fires at the WUI becomes a challenging task. Here, we take advantage of the new Planet Doves satellites constellation to overcome the spatio-temporal drawback and assess WUI fire at the Mediterranean city of Haifa, Israel, which occurred at the end of 2016. First, time series of NDVI from Planet Doves where compared with MODIS (at the MODIS spatial resolution) to extract the proper images that corresponds mainly to the woody vegetation in the burnt area. We used for that purpose a discrimination method of subpixel separation to distinguish between woody and herbaceous vegetation in the WUI area. Then, burnt severity was determined using Planet-derived NDVI of the woody vegetation and information acquired through a field survey in the burnt area. High-resolution (3-m) maps of stand density and woody biomass prior to the WUI fire where generated together with a burn severity map to assess the level of damage at the WUI. Finally, and after validating the maps with ground truth data, we used these maps with a combination of an economical model to assess the economic damage of the WUI fire. As far as we know, this is a first attempt to assess economic damage of wildfires at the WUI. Using methods developed in this study and the high spatial and temporal Planet Doves images has a great potential in future WUI economic assessment elsewhere.