CGRG Bibliography of Canadian Geomorphology
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Author : Harris, K.; and Walker, I.J.
Date : 2007.
Title : Estimating beach sand storage capacity of drift log jams using LIDAR: East Beach, Haida Gwaii, British Columbia.
Publication : Annual Meeting, Western Division of the Canadian Association of Geographers, March 8-10, 2007. University College of the Fraser Valley, Abbotsford, British Columbia.
Issue : Program and Abstract Volume.
Page(s) : 28.
Abstract
This paper presents a novel methodology for calculating sand storage capacity of driftwood jams (DWJ) in coastal environments using LiDAR and GIS technology. As anthropogenic features, DWJ have historically altered the backshore sand storage capacity on beaches throughout the NE Pacific by acting as a trapping "matrix" for aeolian sediments. In some cases, the surplus of sand and debris stored in DWJ offers protection of the backshore against wave and storm surges that may not have existed under natural (i.e., pre-historical) conditions. To test the methodology, two sections of driftwood-laden beach (each ~55 m wide and 1000 m long) were chosen for analysis. Sites were selected based on DWJ size, density of logs, sand infill state, and lack of confounding features (e.g., backshore swales, vegetation cover). LiDAR intensities were used to classify DWJ vs. sand surfaces and GIS comparison of these surfaces allowed for estimation of both total storage potential of the DWJ and the volume of sand currently held in the DWJ matrix. This storage potential was then compared to that of nearby foredunes on sections of the beach that lack DWJ. From this, implications for sea-level rise impacts are discussed.
Bibliography of Canadian Geomorphology