Distribution Characteristics of Environmental Factors and Eutrophication Assessment in the Yancheng Coastal Areas

Abstract

Spatial and temporal variations of nutrients and COD in the coastal waters of Yancheng coastal areas were studied based on three seasonal cruises during 2018. Both the organic pollution appraisal index (Q) and the eutrophication index method (E) were used to evaluate the eutrophication of the seawater. The results showed that the spatial-temporal distribution of E and Q were similar in the study area and showed a greater sequence of spring than that of autumn, which is greater than that of summer in the seasonal variation, decreasing gradually away from the shore. The seasonal variation of environmental factors was significant.The clusters analysis showed that the environmental factors could be divided into two groups:the abandoned yellow river and radial sand ridges. The input of rivers entering the sea in Yancheng had a strong influence on the distribution of pollutants,while the hydrodynamic conditions also affected the distribution of environmental factors.The temporal and spatial distribution of the eutrophication index were regulated to a large extent by the runoff.

Keywords

• nutrient salts
• eutrophication
• marine environment