The impact of thermal water discharging from the Shanghai World Expo´s projects on temperature rise in the Huangpu River

By using the three-dimensional Estuarine, Coastal and Ocean Model ECOM-si, the impact of thermal water discharging from the Shanghai World Expo´s projects on temperature rise in the Huangpu River is studied. Meteorological data and water temperature data are collected to calculate the surface heat flux. Water elevation was validated and surface heat flux was calibrated. The semidiurnal flood and ebb current, spring and neap tide, diurnal inequality of tide in the Huangpu River are reproduced. The simulation results show that the impact of thermal water discharging is within 0.2 °C in most areas in the Huangpu River. The time-averaged vertically-averaged temperature rise is under 0.15 °C during spring tide and under 0.10 °C during moderate tide and neap tide, except for a tiny area of less than 0.2 km². During spring tide, the area of temperature rise over 0.1 °C is near the Expo projects. With the decrease of tide, the effect of runoff of the Huangpu River becomes stronger, and the area of the higher temperature rise moves downstream. Areas of time-averaged vertically-averaged temperature rise over 0.2 °C during neap tide, moderate tide, and spring tide are all as tiny as 0.01 km². Surface temperature rise near the Expo Energy Center is the most significant. Due to the small current speed, the surface temperature rise gathers around the Expo Energy Center, where there appears an area of time-averaged surface temperature rise over 0.3 °C during neap tide, and the area is about 0.01 km². In conclusion, the impact of thermal water discharging from the Shanghai World Expo´s Projects on temperature rise is small.