A novel ecological risk assessment approach applied to Jiangsu coastal zone, China

Abstract

Natural and anthropogenic risk factors contribute to ecological risks in coastal zones; however, the response of ecological entities (receptors) to disturbances varies with the risk source. We used the risk causal law as a guide to construct an ecological risk assessment method for Jiangsu coastal zone, China, with different ecological receptors as the research subjects. We screened the evaluation indicators for natural and anthropogenic risks, validated the evaluation results, and designed a method to map the integrated coastal ecological risk. The five typical ecological receptors exhibited different risk responses when faced with different disturbances. Among the natural risks, invasive species and seawater pollution had the largest differences in risk values. Of the anthropogenic risks, the largest differences in risk values were for reclamation sea farming and industry. The results of the habitat risk assessment model, which were based on the exposure–consequence framework, and those of the hazard–vulnerability–damage model showed a strong positive correlation. Furthermore, the T-test results were tested with P values of less than 0.05, and were not significantly different at the 95% confidence level; thus, the results were valid. The variability in the evaluation results of different ecological receptors was used to map the integrated ecological risk. High- and very-high-risk areas were distributed along the coastline and the edge of the radiating sand ridge, and moderate-risk areas were distributed within the high-risk mudflat areas. The ecological risk values were quantified for each shore section; very-high-risk areas were mainly distributed in the central and estuaries shore sections, and moderate-risk areas were mainly distributed in the southern shoreline sections. The exposure and consequence values calculated using InVEST-HRA model were used to select ten primary factors represented by coastal erosion and sewage discharge as well as five secondary factors represented by green tides and coastal engineering. Finally, we suggested future ecological protection and risk prevention measures based on the shore sections and primary and secondary factors. This study takes the causal relationship of the risk occurrence process as a guideline, and combines the reflected difference characteristics among the risk elements to provide scientific support for the practice of ecological risk prevention and governance in the coastal zone.