Role of Sedimentation in the Phosphorus Budget of Natural and Artificial Iowa Lakes

摘要

The limnological factors that influence sedimentation rates in natural and artificial lakes were studied and an empirical phosphorus model to predict lake total phosphorus concentrations was developed and tested. Sediment traps were used to measure phosphorus sedimentation rates in four natural and four artificial Iowa lakes. While the sedimentation rates were found to be highly variable they were found to directly and significantly correlate with mean inorganic suspended matter concentrations and inorganic sedimentation rates. The rates measured in the Iowa lakes indicated that the lakes were losing from 5% to 60% of their total phosphorus daily. Nutrient budget data from 290 natural and 433 artificial lakes in the U.S., Canada, and Europe, were used as a data base for a simple empirical phosphorus loading model that is based on the Vollenweider equation for input and output of phosphorus in lakes. The model was tested and found to predict lake total phosphorus concentrations equally well in both natural and artificial lakes.