LIDAR as a tool for channel morphology assessment in Baltimore Ecosystem Study watersheds
Andrew J. Miller, UMBC,
James A. Smith, Princeton University,
Amelia M. Bergbreiter, Princeton University,
Michael McGuire, UMBC,
Erin Lesh, UMBC
LIDAR (Light Detection and Ranging) is rapidly emerging as an important tool for high-resolution topographic mapping. State and federal agencies have embraced the application of this technology for flood inundation studies. Digital products delivered to the end user include a grid or irregular network of XYZ data points with maximum vertical accuracy on the order of 15 cm and horizontal spacing on the order of 1m, but under some circumstances as fine as 30-60 cm. Large areas can be covered quickly and the active LIDAR signal yields multiple returns from each individual pulse, allowing the use of filtering algorithms that can strip away vegetation and buildings to reveal the underlying surface with extraordinary detail. Preliminary tests of a LIDAR data set acquired for research projects associated with the Baltimore Ecosystem Study indicate that a data set with horizontal point spacing of 0.75 m can capture the geometry of virtually the entire drainage network. In addition to applications for hydraulic modeling of flood flow, this capability opens up new opportunities for research on longitudinal trends in channel morphology and comparative studies of urban impacts on channels under varying development scenarios. We will discuss some of the advantages and limitations of this tool.
LIDAR, geomorphology, hydrology, stream channels, floods