Essential Site Maintenance: Authorea-powered sites will be updated circa 15:00-17:00 Eastern on Tuesday 5 November.
There should be no interruption to normal services, but please contact us at [email protected] in case you face any issues.

loading page

The ground-truth about lidar-derived digital elevation models in coastal wetland regions of the northern Gulf of Mexico
  • +4
  • Jin Ikeda,
  • Peter Bacopoulos,
  • Jeff Danielson,
  • Brady Couvillion,
  • Shu Gao,
  • Stephen Medeiros,
  • Scott Hagen
Jin Ikeda
Louisiana State University

Corresponding Author:[email protected]

Author Profile
Peter Bacopoulos
Louisiana State University
Author Profile
Jeff Danielson
Organization Not Listed
Author Profile
Brady Couvillion
U.S. Geological Survey
Author Profile
Shu Gao
Luisiana State University
Author Profile
Stephen Medeiros
Embry-Riddle Aeronautical University
Author Profile
Scott Hagen
Louisiana State University
Author Profile

Abstract

Recent advances in the quality and availability of lidar permit high spatial resolution in digital elevation models (DEMs). However, large-scale lidar acquisitions may be flown during high tides, storm events, and irregular tidal regimes leading to temporal change differences, but ultimately the uneven penetration through dense vegetation impacts the reality of ground surface positions. For the low-gradient coastal land margin of the northern Gulf of Mexico, even a small elevation bias (on the order of 0.1 m) can adversely affect surface hydrodynamic model accuracy. Therefore, ground-truthing with a vertical elevation adjustment is essential for robust biogeophysical modeling. This study assessed measurement errors of lidar-derived DEM datasets (1 m DEMs), developed in 2021. The DEM was evaluated for distinct coastal wetlands, especially coastal marshes of Louisiana, Mississippi, and Alabama. Error analysis was conducted using Real-Time Kinematic (RTK) GPS to assess how well the lidar-derived elevations represent the actual marsh surface (ground surface). The performance of the temporally and spatially distinct lidar-derived elevation datasets was evaluated over 7,000 elevation points measured between 2011-2021. We also examined the relationship between measurement errors and vegetation characteristics (marsh type, height, and percent cover). This presentation will demonstrate our ongoing efforts to assess the high-resolution lidar-derived elevations in coastal wetlands and discuss the measurement errors.