Reach Sensitivity Index Classification of Louisiana Coastal Rivers: A Tool for Watershed Restoration
H. Dallon Weathers, Miles Hayes, and Rebecca Murphey
RPI-Louisiana, CERM Building, Suite 505, 2045 Lakeshore Dr., New Orleans, Louisiana 70122
In recent years, the focus on issues regarding water quality has shifted from local site-specific view of a problem towards a holistic view where the health and integrity of entire watersheds are of concern. The goal of this project was to map the watersheds of the Tangipahoa, Tchefuncte, Tickfaw, and Natalbany rivers, draining from the Florida Parishes of Louisiana, with respect to a Reach Sensitivity Index. Because the Reach Sensitivity Index approach required careful analysis of watersheds through a combination of field visits and remote sensing, a second goal was to address other issues relating to watershed impairment and restoration. The Reach Sensitivity Index classification scale is based on stream geomorphology, hydrology, and ecological characteristics where rank is given based on morphological complexity and associated wetlands. Data from 100 field sites were used along with USGS 7.5 minute topographic maps, Digital Ortho Quarter Quads 1-meter resolution infrared aerial imagery, GAP land cover data, and Digital Elevation Models generated from LIght Detection And Ranging data to classify stream reaches according to the Reach Sensitivity Index scale. Key anthropogenic impacts observed throughout the watersheds were related to sand and gravel mining, stream manipulation, profuse litter, and overall water quality. Reach Sensitivity Index stream classification can serve as a tool for conservation strategies and watershed restoration, where the ultimate goal is to restore natural hydrological and ecological functionality to impaired streams. Maps generated in the Reach Sensitivity Index project can further aid in regional planning, without which, rapid urban development and continued stream manipulation within the Florida Parishes will result in accelerated watershed impairment and water-quality degradation.
AAPG Search and Discovery Article #90080©2005 GCAGS 55th Annual Convention, New Orleans, Louisiana