Using High-Resolution Planet Satellites Constellation Images to Assess Economic Damage of a Wildland–Urban Interface Fire

The wildland-urban interface (WUI), the area where wildland vegetation and urban buildings meet, is at a greater risk of fire occurrence because of the extensive human activity in this area. Although satellite remote sensing has become a major tool for assessing wildland fire damages, it is unsuitable for WUI fire monitoring due to the trade-off between the spatial and temporal resolution of the images. Here, we take advantage of frequent (c. daily), high-spatial-resolution (3m) imagery acquired from a constellation of nano-satellites operated by Planet to assess fire damage in the WUI of a Mediterranean city in Israel (Haifa). The fire occurred at the end of 2016, consuming c. 17,000 of the trees (152 trees ha-1) within the near-by wildland and urban parts of the city. Three vegetation indices (GNDVI, NDVI and GCC) from Planet satellite images were used to derive a burn severity map for the WUI area after applying a subpixel discrimination method to distinguish between woody and herbaceous vegetation. The produced burn severity map was validated with information acquired from an extensive field survey in the WUI burnt area. Planet's vegetation indices were calibrated using in-field tree measurements to obtain high-resolution maps of burned trees and consumed woody biomass in the WUI. These were used in conjunction with an ecosystem services valuation model (i-Tree) to estimate spatially distributed and total economic loss caused by the fire. We conclude that using the method developed in this study with high-spatial resolution Planet images has a great potential for WUI fire economic assessment.