Dynamics and Biogeochemistry of River Corridors and Wetlands (Proceedings of symposium S4 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 294, 2005, 102-113

1 Japan Science and Technology Agency, 2-1-6 Kannondai, Tsukuba, Ibaraki 305-8609, Japan

2 National Institute for Rural Engineering, 2-1-6 Kannondai, Tsukuba, Ibaraki 305-8609, Japan

Abstract The decline of river corridor vegetation density strongly affects the river thermal environment, which also has a large impact on the ecological systems. In this study, a stream temperature analysis model related to river corridor vegetation density was developed and applied to the Nam Song River in Laos. Meteorological data (air temperature, relative humidity, wind speed) were used, and the sink or source terms of the heat transfer equation were estimated from those data. Land cover GIS data was used for vegetation density analysis along the main river. The results of simulation with several levels of vegetation density indicate that river water temperature is more sensitive to river discharge change in the case of low vegetation density.

Key words heat transfer equation; Laos; Mekong River; river corridor conservation; river thermal environment; solar radiation estimation; vegetation density