Fire Danger Assessment Using Moderate-Spatial Resolution Satellite Data

Abstract

Fire is one of the most common disturbances in natural ecosystems. The analysis of various sources of information (official and unofficial) about the fires in Ukraine (2019–2020) showed a lack of timely and reliable information. Satellite observation is of crucial importance to provide accurate, reliable, and timely information. This paper aims to modify the index of fire danger of a forest’s FWI by increasing its precision, based on the use of higher spatial resolution satellite data. A modification of the FWI method involves the utilization of the soil moisture deficit, in addition to the six subindices of the FWI system. In order to calculate the subindices values, weather data from the Copernicus Atmosphere Monitoring Service were used. Soil moisture deficit is calculated using Sentinel-1 radar satellite data on the water saturation degree of the soil surface layer and geospatial parameters from the 3D Soil Hydraulic Database of Europe. The application of the proposed methodology using the specified satellite, weather, and geospatial data makes it possible to assess fire danger on a continental scale with a spatial resolution of 250 m, 1 km, and a daily temporal resolution. Validation of the proposed method for modifying the FWI system demonstrates an improvement in the precision and relevance of fire danger prediction.

Exploring Forest Fire Dynamics: Fire Danger Mapping in Antalya Region, Türkiye

“…DC measures the organic moisture content at a depth of 10-20 cm in the forest floor [38,71]. These three subcomponents collectively describe fuel conditions, ranging The FWI system consists of six distinct subcomponents, with three of them (FFMC, DMC, and DC) specifically associated with fuel moisture codes, while the remaining three (ISI, BUI, and the general index FWI) function as fire behavior indexes [56]. The FFMC measures moisture content in combustible materials such as branches, leaves, dry grasses, bark, and other substances located at a depth of 0-2 cm on the forest surface, providing crucial insights into moisture levels within this thin layer of deceased organic cover, including debris and residues.…”

“…BUI is also a numerical indicator, combining DMC and DC to represent the total fuel available for combustion. The last index, FWI, combining ISI and BUI, serves as a numeric indicator of fire intensity, with low values indicating low fire danger and higher values suggesting increased fire danger conditions [56].…”

“…In a study of Siberian Forest fires, based on 2002-2009 satellite data analysis, moisture levels from the previous summer were found to be a more reliable predictor of burned areas in larch forests than precipitation anomalies or fire weather indices [55]. An improvement to the FWI methodology has been proposed by incorporating the soil moisture deficit factor to formulate a comprehensive fire danger index [56]. In this context, Sentinel-1 radar satellite data were used to calculate soil moisture in order to evaluate the degree of water saturation in the soil surface layer.…”

Google Earth Engine Framework for Satellite Data-Driven Wildfire Monitoring in Ukraine

“…Its disadvantage is low spatial resolution due to the use of meteorological data with a resolution of 1 km. In article [8], the authors modified the FWI forest fire danger index for the territory of Ukraine by increasing its accuracy based on the use of satellite data with a higher spatial resolution, as well as by using soil moisture deficit, in addition to the six sub-indices of the FWI system.…”

“…The disadvantage of this approach is low spatial resolution and, as stated in article [7], the use of such data underestimates the number of identified fires by 30-60%. In addition to establishing the locations of fires, the determination of the cause of the fire-due to dry weather conditions [8,9] or due to human activities-is currently also an urgent issue at the country level. It is especially important during the war in Ukraine when some territories are not accessible.…”