Submitted to: Remote Sensing of Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 15, 2000
Publication Date: October 15, 2000
Interpretive Summary: An airborne scanning laser has been used to study the distribution and height of shrub covered dunes in an arid rangeland in New Mexico. The laser provides a new tool for determining the height of these dunes over large areas.
Technical Abstract: Since the 1880's, rangeland vegetation in southern New Mexico has changed dramatically over widespread areas, typically with shrubs displacing native grasslands. Coincident with these changes in vegetation dominance are increases in soil erosion, stream channel cutting, and shrub-coppice dune formation on sandy soils. Where marked differences in vegetation type from mgrassland to honey mesquite shrubland have occurred, the local topography has been transformed with previously flat mesa becoming rolling duneland. The size, distribution, and morphological characteristics of these dunes have an important impact on fluxes of energy and nutrients at the surface as well as rendering the land far less useful as grazingland for domestic livestock. These shrub-coppice dunes and the mesquite shrubs which grow on them may be considered roughness elements. Quantifying their morphology is important for the calculation of aerodynamic roughness length and displacement height. This article describes the application of active scanning laser remote sensing techniques in providing accurate estimates of the three-dimensional shapes and areal distributions of dune and interdune areas. It shows that coarse scanning laser can be used to measure the morphological characteristics of shrub-coppice dunes in the desert grasslands of southern New Mexico with acceptable accuracy and precision for a range of uses including important geomorphological and hydrological applications. The use of scanning laser systems, together with optical multispectral data, is shown to be highly synergistic providing information which is not easy to obtain via other survey methods.