Satellite-based mapping of purple moor grass for wildfire fuel load assessment in heathlands

Purple moor grass is a major invasive grass species in heathlands across Western Europe. Due to its ability to quickly accumulate flammable biomass, purple moor grass could influence the fire risk in these open landscapes. In this study, we have demonstrated the potential of monthly NDVI and NDMI time series derived from the freely available Sentinel-2 data catalogue for distinguishing between areas with low and areas with high coverage of purple moor grass. While the results within a single year are excellent, temporal transferability remains a challenge. This could potentially be overcome by the use of phenological and/or bitemporal input features.