Author(s): Yuki Kajikawa; Hiroshi Yajima
Linked Author(s): Yuki Kajikawa, Hiroshi Yajima
Keywords: Stream temperature; Mountainous river; 1D MacCormack model; Numerical simulation; Field observation; Stream-width
Abstract: In this study, a long-term simulation model for stream temperature variation was developed in order to predict the influence of a reservoir effluent on the downstream river environment. A 1D hydrodynamic MacCormack model was adopted along with thermodynamic models. The relation between flow discharge and stream-width was applied at the time of low flow discharge to accurately estimate surface thermodynamics. Moreover, the stream-width was calculated by the hydrodynamic model assuming compound cross-sections at the time of high flow discharge. Both methods were made to switch automatically according to the discharge. The model was applied to the field observation performed for the Fukuro River which flows through the mountainous area in Japan. The comparisons of the calculated results with observed data showed that the model has successfully reproduced the stream temperatures with approximately less than 1.0 oC differences.
Year: 2011