Analysis of Bottom Sediment to Estimate Nonpoint-Source Phosphorus Loads for 1981-96 in Hillsdale Lake, Northeast Kansas

摘要

Bottom sediment in Hillsdale Lake, northeast Kansas, was analyzed as a means ofestimating the annual load of total phosphorus deposited in the lake from nonpoint sources. Topographic, bathymetric, and sediment-core data were used to estimate the total mass of phosphorus in the lake-bottom sediment. Available streamflow and water-quality data were used to compute the mean annual mass of phosphorus (dissolved plus suspended) exiting the lake as well as the mean annual load of phosphorus added to the lake from point sources. A simple mass balance then was used to compute the mean annual load of phosphorus from nonpoint sources.