Improvement of streams hydro-geomorphological assessment using LiDAR DEMs

Auteur(s) et Affiliation(s)



Description :
The AA. aim at developing geographic information system (GIS) tools to extract channel slope, width and discharge from 1 m-resolution LiDAR DEMs to estimate the spatial distribution of unit stream power in 2 contrasted watersheds in Quebec : a small agricultural stream (Des Fèves River) and a large gravel-bed river (Matane River). For slope, the centreline extracted from the raw LiDAR DEM was resampled at a coarser resolution using the minimum elevation value. The channel width extraction algorithm progressively increased the centerline from the raw DEM until thresholds of elevation differences and slopes were reached. Based on the comparison with 4000 differential global positioning system (GPS) measurements of the water surface collected in a 50 km reach of the Matane River, the longitudinal profile and slope estimates extracted from the raw and resampled LiDAR DEMs were in very good agreement with the field measurements and can thus be used to compute stream power. The estimated maximum unit stream power spatial patterns corresponded well with field evidence of bank erosion, indicating that LiDAR DEMs can be used with confidence for initial hydro-geomorphological assessments.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2013, vol. 38, n°. 15, p. 1808-1821, nombre de pages : 14, Références bibliographiques : 1 p.

Date :
2013

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley