| Water quality assessment plays a crucial role in preventing environmental risks in coastal waters. This study establishes an entropy-weighted composite index by integrating entropy weighting into the single-factor pollution index framework. Using the Tianweishan marine area in Shanwei City as a case study, we analyzed water quality monitoring data from 2021 to 2022 across different seasons. The evaluation of water quality through both the composite pollution index and entropy-weighted composite index demonstrates the scientific validity of the improved assessment method. Results indicate that the water quality meets China爷s Class III seawater standards, with low pollution risks. However, the water quality shows a slight downward trend seasonally. The high-impact zones, influenced by the multimorphological dynamics of the East Guangdong Upwelling combined with monsoon and topographic factors, are primarily located in offshore waters. Key influencing factors include suspended solids (SS), dissolved oxygen (DO), dissolved inorganic nitrogen (DIN), and oil, with lead (Pb) identified as the primary environmental risk. Compared to adjacent waters, elevated levels of copper (Cu) and zinc (Zn) were detected in spring. Unlike the composite pollution index method, the entropy-weighted approach comprehensively considers regional water quality characteristics and the varying impacts of environmental factors on coastal ecosystems, yielding more rational and discriminative assessment results. |
