Author(s): Kathleen D. White; Jeffrey P. Laible
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Keywords: No Keywords
Abstract: Diurnal fluctuations of dissolved oxygen (DO), along with changes in river microbiology during winter, have been observed in an intermittently ice-covered, relatively nutrient-rich river in Vermont during two winter seasons. The diurnal cycling of DO that persists during the ice-covered period appears to be related to photosynthetically active radiation (PAR). A finite element model (FEM) based on the analytical expressions for DO concentration developed by Streeter and Phelps (1925) was extended to explore the relationship between DO and PAR. Observed diurnal DO cycling in open water conditions on the LaPlatte River was replicated using a model that included the effects of PAR and effects of air temperature, indicting the importance of photosynthetic activity in rivers during winter. The FEM results suggest that the reaeration coefficient K is notnegligible as reported by several modelers, and probably lies between about 0.5 and 0.75 d.
Year: 2002