Height growth reconstruction of a boreal forest canopy over a period of 58 years using a combination of photogrammetric and lidar models

C. Vega (1) , B. St-Onge (2)

1 UMR TETIS - Territoires, Environnement, Télédétection et Information Spatiale
2 Département de Géographie

Field data describing the height growth of trees or stands over several decades are very scarce. Consequently, our capacity of analyzing forest dynamics over large areas and long periods of time is somewhat limited. This study proposes a new method for retrospectively reconstructing plot-wise average dominant tree height based on a time series of high-resolution canopy height maps, termed canopy height models (CHMs). The absolute elevation of the canopy surface, or digital surface model (DSM), was first reconstructed by applying image-matching techniques to stereo-pairs of aerial photographs acquired in 1945, 1965, 1983, and 2003. The historical CHMs were then created by subtracting the bare earth elevation provided from a recent lidar survey from the DSMs. A method for estimating average dominant tree height from these historical CHMs was developed and calibrated for each photographic year. The accuracy of the resulting remote sensing height estimates was compared to ageheight data reconstructed based on dendrometric measurements. The height bias of the remote sensing estimates relative to the verification data ranged from 0.52 m to 1.55 m (1.16 m on average). The corresponding root-mean-square errors varied between 1.49 m and 2.88 m (2.03 m average). Despite being slightly less accurate than historical field data, the quality of the remote sensing estimates is sufficient for many types of forest dynamics studies. The procedures for implementing this method, with the exception of the calibration phase, are entirely automated such that forest height growth curves can be reconstructed and mapped over large areas for which recent lidar data and historical photographs exist.

Mots clés: TELEDETECTION; FORET; CROISSANCE EN HAUTEUR; PHOTOGRAMMETRIE; CARTOGRAPHIE; CANOPEE; FORET BOREALE; LIDAR

Domaines: Interfaces continentales, environnement; Milieux et Changements globaux; Instrumentations et Détecteurs [physics.ins-det]; Etudes de l'environnement; Modélisation et simulation; Vision par ordinateur et reconnaissance de formes [cs.CV]; Traitement du signal et de l'image [eess.SP]; Sciences de l'environnement; Traitement du signal et de l'image [eess.SP]

C. Vega, B. St-Onge. Height growth reconstruction of a boreal forest canopy over a period of 58 years using a combination of photogrammetric and lidar models. Remote Sensing of Environment, 2008, 112, p. 1784 - p. 1794. ⟨10.1016/j.rse.2007.09.002⟩. ⟨hal-00453861⟩