Spatiotemporal monitoring of post-fire soil erosion rates using earth observation (EO) data and cloud computing

This research addressed on the crucial concern of soil erosion in the post-fire Mediterranean landscapes, regarding disastrous wildfires in Greece during 2021. These fires broke out at the Varympompi, Schinos, and Ancient Olympia-Gortynia. To accomplish these goals, the Revised Universal Soil Loss Equation (RUSLE) and Earth Observation (EO) data coupled with Google Earth Engine (GEE) were used to quantify the wildfire effects on erosion dynamics in the burned areas as well as the regulation provided from the emergency post-fire rehabilitation treatments. High-resolution EO data such as Sentinel-2 imagery and climate data from ERA5-Land were processed over the GEE platform to assess soil erosion factor changes before and after the fire occurrence. The analysis was followed up by measurements of the vegetation recovery and rainfall erosivity, which are crucial for the knowledge of erosion processes in such regions. Results displayed great increases in soil erosion post-fire, with rates at Ancient Olympia-Gortynia rising to 118.3 t ha(-1) y(-1) in the first hydrological year after fire from pre-fire rates of 9.8 t ha-1 y-1. At Schinos site, rates increased from a pre-fire average of 11.6 to 72.2 t ha(-1 )y(-1), and in Varympompi, from 4.8 to 28.8 t ha(-1) y-1. Post-fire restoration works reduced erosion processes by approximately 18%. Coupling RUSLE with GEE offers a novel opportunity for dynamic monitoring of soil erosion towards informing land management and policy formulation in the fire-prone Mediterranean ecosystems in relation to the mitigation of erosion. The policy formulation on land management within fire-prone Mediterranean-type ecosystems stands to be influenced by the findings of the current study. Indeed, this is of worldwide importance, whereby management practices need to be adopted to ensure that ecosystems recover rapidly and effectively after fires for the conservation of soil resources.