A geospatial tool for delineating streambanks

Abstract

Ecologists, civil engineers, and conservation managers currently lack an automated software tool for delineating streambanks, which is an important input for various hydrological studies. Therefore, a computational method for automatically delineating streambanks using aerial imagery and stream centerline datasets was developed and incorporated in a stand-alone, user-friendly desktop-based geospatial tool. This interactive tool, titled Streambank Delineator (StreBanD), was tested on the 161-km Lower White River and 158-km L'Anguille River in Eastern Arkansas using 1-m resolution 3-band aerial imagery and National Hydrography Dataset Plus (NHDPlus) stream centerline. The near-infrared band and normalized difference water index (NDWI) were evaluated for feasibility of streambank delineation. Results showed that the NDWI, a multi-band index approach, consistently provided superior delineations when compared to the single band (near-infrared) approach especially for complex channel morphologies, including braided channels and meandering segments, in the L'Anguille River. The geospatial tool successfully delineated the streambanks for both rivers in less than 10 min with a mean error ranging from 0.3 m to 10.3 m when compared with five manually delineated streambanks. Due to the generic and simple nature of this tool, it should assist scientists and conservationists in rapidly delineating streambanks for their study areas.