Abstract
To reveal factors relevant in controlling stream temperatures in summer season in the Tama River, field measurement, water and heat budget analysis as well as model development were performed in this study. Detailed information on water temperature, flow rate, meteorological variables as well as water-sediment heat flux was obtained through the intensive field measurement. Water and heat budgets analysis indicated that the wastewater effluents contributed to mitigate stream temperature at one middle stream site. A 1-D dynamic model for river flow and heat transport was developed, taking the effect of groundwater-stream water interaction processes and wastewater effluents into accounts. We concluded that the current stream temperature regime in the Tama River downstream reaches is maintained by the heat dispersion in the riverbed sediment and also the effluents of treated wastewater.
