Abstract

Developing a Structures Database and Modified Terrain Model from Lidar
Track: Water, Wastewater, and Stormwater
Authors: Andrew Kuster, Carrie McCrea

High-quality lidar data was used to develop a structures geodatabase and modified terrain model for a stormwater authority. Raw lidar point cloud data within the study boundary were processed and filtered to isolate bare earth, surface, and canopy. This information, used in conjunction with lidar intensity and aerial images, allowed for the identification of points that represent buildings. Structure footprints were defined through further data analysis and extracted as polygons (the truly unique part of this project). Attributes for each structure include base elevation, footprint area, building height, roof angle, flood zone, etc. The geodatabase will be used primarily for floodplain management, flood-depth modeling, and critical infrastructure planning. An updated topographic model was also produced by adding the structures to the bare earth terrain representation. The result more accurately represents actual topologic conditions for hydraulic analysis. Presentation will address methodology, successes, limitations, and lessons learned in regard to polygon extraction.