Utilizing Civil Geo-HECRAS Capabilities for Floodplain Mapping of Colorado River in Texas during Hurricane Harvey

摘要

It is evident that the south coastal regions of the U.S. have been hit hard with frequently occurring tropical storms and hurricanes in recent times. These storms have been more disastrous because they resulted in high intensity rainfall events, which ultimately caused flooding in the region. Flows larger than a 500-year flood have occurred in some regions, which justifies the Federal Emergency Management Agency's updated policy of incorporating 500-year return period flows in flood-risk assessment studies. Recently, Hurricane Harvey has hit different regions in Texas causing extensive damages to lives and properties. This study focused on performing the flood frequency analysis along the Colorado River in Texas and developing the floodplain maps for Columbus, Wharton, and Bay City in Texas. The frequency analysis was performed to generate flows for different return periods-10, 100, and 500 years and the corresponding floodplains were delineated using Civil Geo-HECRAS, developed by Chris Maeder of CivilGEO team. The result in terms of flood extent and depth were compared with the inundation extent resulting from the Hurricane Harvey. This study can assist managers and policy makers in delineating high risk areas, planning for stormwater management, and vulnerability assessment of the infrastructures.