“Using airborne lidar to map river morphology and habitat”: Talk by

GED Seminar Series

Thursday 3^rd May 2012

3-4pm, CO304 (NOTE CHANGE OF TIME)

Speaker: Associate Professor Noah Snyder, Boston College

“Using airborne lidar to map river morphology and habitat”

Much progress has been made linking the fields of geomorphology, hydrology, ecology and tectonics over the past 20 years using digital elevation models (DEMs) to study stream processes. The first-generation DEMs were generated from topographic maps, and with pixel sizes of 10 to 90 meters on each edge, these grids allowed investigators to make measurements of parameters such as stream gradient and contributing drainage area over entire channel networks. Next-generation DEMs generated from airborne laser elevation (lidar) surveys open up new opportunities for research on stream processes because they improve resolution by an order of magnitude compared to traditional DEMs. With pixel sizes of 0.5 to 5 meters and the ability to measure height down to 5 to 20 centimeters lidar DEMs enable researchers to identify channel features, such as the water surface, bank edges, and floodplains, as well as measure the slope of channels over short stream reaches. Furthermore, they provide new types of data about watershed land cover, such as the height and density of the tree canopy, because the laser instrument receives returns from both treetops and the land (or water) surface. In this talk, I will present several applications of airborne lidar data to study channel processes, morphology and habitat in North American rivers.