Water and Heat Transport Characteristics and Wastewater Impact on Stream Temperature Under Tidal Validation

Abstract

Thermal environment in an urban river system can be significantly changed due to wastewater heat. If the stream temperature increases due to the wastewater heat, it is likely to damage the river ecosystem. On the contrary, the wastewater heat can be used effectively for heat energy. In this paper, the results of an intensive observation and dynamic simulation of water and heat transport in lower reaches of Ara River were reported.
Firstly, we clarified the actual state of the heat transport in lower reaches of the Ara River by the observation. It was found that Ara River receives a lot of heat from Sumida River and Shingashi River through the Iwabuchi gate. Secondly, stream temperature was reproduced using one-dimensional model which integrated water and heat transport process. Finally, wastewater impact on stream temperature in lower reaches of the Ara River was quantitatively evaluated using the dynamic simulation model. Consequently, it was found that wastewater increases stream temperature by 3 'C at the maximum in winter.