Thermal Pollution Monitoring of Tianwan Nuclear Power Plant for the Past 20 Years Based on Landsat Remote Sensed Data

The Tianwan nuclear power plant is located in Jiangsu province of China. It discharges warm water from its cooling system into the Yellow Sea, which is bound to have ecological consequences. Herein, the changes in sea surface temperature (SST) after the operation of the Tianwan nuclear power plant were studied using Landsat data. First, the SST near the Tianwan nuclear power plant was estimated using a single-channel algorithm; subsequently, the datum temperature was extracted. Second, the area of thermal discharge was calculated. Finally, the thermal discharge was continuously monitored and analyzed, together with the overall trend of thermal discharge, its seasonal distribution characteristics, and the relationship between temperature rise and the impact of thermal discharge on the marine environment. Furthermore, there was no evident temperature pollution before the nuclear power plant was put into operation in May 2007; however, after the operation of the nuclear power plant, the thermally polluted area clearly expanded. An expansion of 66.77 km
²
was observed from 2001 to 2020 for areas experiencing higher temperatures. The largest thermally polluted area is observed in spring, followed by those in summer, winter, and autumn. In 2018, the temperature rise area in winter is 44.82 km
²
larger than that in autumn. The rise in SST at the Tianwan nuclear power plant meets the national quality standards for marine environments, and does not pollute the surrounding environment.