Thermal balance of on-stream storm-water management pond

A methodology and assessment of the thermal balance of an on-stream storm-w ater pond are documented for a test facility in Kingston, Ontario, Canada. An energy balance model was used to estimate average pond water temperature as a function of thermal energy stored in the pond. Major thermal energy f luxes considered within the pond system included radiant heating and coolin g of the pond, evaporation, and thermal energy inflow from the upstream cat chment and outflow from the pond. A thermal energy balance was achieved bet ween thermal energy input and output measured over the field season. During dry-weather periods, pond temperature increased as a result of solar heati ng, and thermal energy input exceeded output. Conversely, during wet-weathe r periods, pond temperature decreased as a result of limited solar radiatio n and replacement of warm pond water by cool inflow water from the upstream catchment, and thermal energy output exceeded input. A series of discrete temperature surveys in the pond revealed that the location of the stationar y temperature probe, used to measure pond temperature, resulted in an under estimation of the average pond temperature during dry and wet-weather perio ds. However, this discrepancy was comparable to the difference between meas ured and modeled values, which further confirmed the model validity.