Use of LiDAR-Based Elevation Data for Highway Drainage Analysis: A Qualitative Assessment

Small-scale elevation models may not provide the accuracy and detail necessary to accurately delineate small watersheds. Moreover, they may not accurately reflect the impact of roads and their ditches on these small watersheds, particularly in flat areas. This research study investigates the differences of utilizing high resolution LiDAR and standard USGS-based elevation data for watershed and drainage pattern delineation along the Iowa 1 corridor between Iowa City and Mount Vernon. Given the limited breadth of the analysis corridor (approximately 18 miles long with LiDAR data available immediately proximate to the road centerline, 0.25 to 1.5 miles), areas of particular emphasis are the location of drainage area boundaries and flow patterns parallel to and intersecting the road cross section. Key words: highway engineeringhydrology remote sensing––LiDA