Ongoing project · principal investigator

Fuels, Fire, Flourish: remote sensing synergies to unravel fuel dynamics, fire impact and forest recovery

3F builds an integrated system that follows live fuels through every phase of a fire — from pre-fire fuel status, through combustion and fire impact, to post-fire recovery — using terrestrial, airborne and spaceborne sensors. It takes advantage of the first dual-frequency (S- and L-band) SAR mission, NISAR, and of near-simultaneous C-band (Sentinel-1) and L-band dense time series, and it applies artificial intelligence to integrate data streams from national, European and international Earth Observation programmes.

Objectives

Characterise and monitor fuel structural properties

Canopy fuels — fuel load, canopy height, canopy base height, canopy cover, canopy bulk density — and understory fuels — density and height. Reference information comes from high-density airborne lidar, propagated through time and space with satellite time series, pixel-level disturbance history (1985–2024) and ancillary climate and terrain variables. Terrestrial laser scanning provides the bottom-up view needed to separate understory from canopy.

Fire impact assessment and emission estimates

Redevelop the Radar Burn Ratio within a multi-sensor, multi-wavelength framework so that it carries information from both the top of the canopy (C-band) and below it (L-band), adding interferometric coherence and L-band scattering-centre height. Biome-specific indices are pre-calibrated against in-situ observations, then combined with fuel load to estimate greenhouse gas emissions through a book-keeping approach.

Post-fire recovery from active-passive sensor synergies

Track recovery in all major fire disturbance events in the Spanish Atlas of Forest Disturbances. A repurposed CCDC-SMA analysis detects positive change in the optical signal, then lidar and L-band radar take over where optical reflectance saturates, giving structural recovery rather than cover recovery alone.

Approach

Demonstrator areasGalicia, Basque Country, Madrid, Andalucia

Large (2–3 M ha) areas forming a north–south transect across the Atlantic and Mediterranean biomes, with contrasting vegetation types and fire regimes.

FuelsPNOA lidar 3rd campaign, TLS, NFI

The third national PNOA lidar campaign at 5 points m⁻² provides the reference canopy fuels; SLAM terrestrial scanning adds the understory; National Forest Inventory plots calibrate the biomass fractions.

Fire impactSentinel-1 C-band, NISAR L-band, FLEX

Multi-wavelength backscatter, coherence and scattering-centre height for a pre-calibrated Radar Burn Ratio; in-situ fire impact data collected in large (>500 ha) fires.

RecoveryHarmonized Landsat Sentinel + lidar + L-band

A 35+ year optical trajectory for regeneration, extended with structural recovery from lidar and radar once the optical signal saturates.

Results

**Canopy base height** Canopy base height across peninsular Spain at 40 m, predicted by the patch-CNN from national airborne lidar. Inset shows the lidar flight year by region. Tanase, Garcia-Martin & Lamelas, under review

**Canopy fuel load and bulk density** The two canopy variables that determine whether an active crown fire can be sustained, mapped over the same area. Tanase, Garcia-Martin & Lamelas, under review

**Deep learning against machine learning** RMSE by region for the tree-stratum variables, comparing the patch-CNN with random forests and gradient boosting. Tanase, Garcia-Martin & Lamelas, under review

Publications

Mapping multi-strata forest fuel attributes across peninsular Spain using airborne lidar data

M.A. Tanase, A. Garcia-Martin, M.T. Lamelas Gracia

Remote Sensing of Environment

under review

Mapping fungal disturbances and logged areas in Pinus radiata forests: a multi-method comparison of Harmonized Landsat and Sentinel-2, Sentinel-1 and AlphaEarth embeddings

V. Wilke Mateos, A. Cantero, M. Tanase

Manuscript in preparation

draft

Mono-temporal mobile laser scanning reveals species-specific vertical structural signatures of fire severity in Iberian pine stands

M.A. Tanase

Manuscript in preparation

draft

Team

Mihai TanasePrincipal investigator · ICIFOR INIA-CSIC

Alberto García MartínResearch team · Centro Universitario de la Defensa, Zaragoza

María Teresa Lamelas GraciaResearch team · Centro Universitario de la Defensa, Zaragoza

Diego Laino RebollidoWork team · University of Alcalá

Victoria Wilke MateosDoctoral student, joined after the application

Guillermo Goday AramburoDoctoral student, joined after the application