Baltimore Ecosystem Study Institute of Ecosystem Studies

2017 BES Annual Meeting Presentation and Poster Abstracts

Monitoring urban stream restoration efforts in relation to flood behavior along Minebank Run, Towson, MD
Lee, Gina
Co-Authors: Andrew J. Miller, UMBC

Abstract: Urban stream restoration efforts are commonly undertaken to combat channel degradation and restore natural stream hydrology. We examine changes in flood patterns along an approximately 1.5-mile reach of Minebank Run, located in Towson, MD, by comparing pre-restoration morphology from surveys conducted in 2001, post-restoration morphology in 2007, and current conditions in 2017 following damage to the restoration project from persistent flooding. Hydraulic modeling was conducted in HEC-RAS 2D using three alternative scenarios: 1) topographic contours from a 2001 survey of pre-restoration topography combined with 2005 LiDAR 2) 2007 survey combined with 2005 LiDAR data representing the post-restoration channel morphology, and 3) a March 2017 DEM of current channel conditions. The 2017 DEM was created using Structure from Motion (SfM) from high resolution 4K video collected via Unmanned Aerial Vehicle (UAV) flights. Flood hydrographs from a USGS stream gage located within the study reach were routed through the pre-restoration, post-restoration, and current modeled terrain and analyzed for changes in water-surface elevation and depth, inundation extent, 2-d velocity fields, and translation vs. attenuation of the flood wave to assess the net impact on potential flood hazards. Our study demonstrates that SfM is quick and inexpensive method for collecting topographic data for hydrologic modeling, assessing stream characteristics including channel bed roughness, and for examining short term changes of channel morphology at a very fine scale that may affect the success of restoration projects.