| Abstract: | ABSTRACT: The Applachicola River basin in northwest Florida covers an area of 3,100 square kilometers. Fifteen percent of the area is a dense bottomland hardwood forest which is periodically flooded. The annual leaf-litter fall from the flood-plain trees is a potential source of nutrients and detritus which eventually can flow into Apalachicola Bay. Transport of such material is dependent on the periodic inundation of the flood plain. The U.S. Geological Survey Apalachicola Rim Quality Assessment measured a total organic carbon flux of 2.1 × 105 metric tons during the one-year period from June 3, 1979, to June 2,1980. Fluxes of total nitrogen and phosphorus during the same year were 2.1 × lo4 and 1.7 × lo3 metric tons, respectively. Flood characteirstics, such as prior hydrologic conditions, extent, and timing, are important in determining the amount and forms of materials transported. The 1980 spring flood produced a fourfold discharge increase over the annual mean outflow of 800 cubic meters per second. Nutrient concentrations varied little with discharge, but the 86-day spring flood accounted for 53, 60, 48, and 56 percent of the annual flux of total organic carbon, particulate organic carbon, total nitrogen, and total phosphorus, respectively. In 1980, the flood peaks, rather than the rise or recession, accounted for maximum nutrient and detritus transport. |
