The Nutrient Pollution Characteristics And Comparison Of Several Assessment Methods Of Eutrophication In Xiangshan-bay

Through analyzing nutrient pollution characteristics,we find that the content of dissolved inorganic nitrogen(DIN) and dissolved inorganic phosphate(DIP) in Xiangshan-Bay marine's water is high,they are all inferior to the 4th class sea water quality standard.Besides,they increase by degrees from the mouth to the bottom of Xiangshan-Bay,especially,the incremental tendency of the content of DIP is more evident.See from the seasonal variation,the content is highest in Winter and lowest in Summer.In terms of the nutrient content,N/P value,E value,A value of the spatial distribution of,or the relevance of nutrients and salinity which infect reflect the space difference from the mouth to the bottom of Xiangshan-Bay,or the comparison between the historical data and current data of nutrients,the land-based sources of pollution are to verify the Xiangshan-Bay marine's water an important source of nutrients,which is the protection and rational development of Xiangshan-Bay region, and maintain the sustainable development of Xiangshan-Bay clear environmental requirements.Evaluate on Xiangshan-Bay's eutrophication degree with two generations of the four eutrophication assessment methods(Nutrition Index Method,Evaluation of Organic Pollution Index Method,Classification & Evaluation of Nutrition and EU"Comprehensive Evaluation") shows that the bay's were on eutrophic condition, which does mean that these four methods have been all effectively certificated through theory and practice.However,according to the comprehensive analysis of the four evaluation methods in the Xiangshan-Bay's eutrophication evaluation,we find that Evaluation of Organic Pollution Index Method and Classification & Evaluation of Nutrition are more reasonable than Nutrition Index Method,which behave better discrimination.In view of the shortcomings of existing data,EU"Comprehensive Evaluation"in the data comparison and analysis can not give full play to its original theoretical advantages,but it is the development trend of eutrophication evaluation in expanding the scope of the marine environment monitoring based on the further exploration and research.To sum up,although Evaluation of Organic Pollution Index Method and Classification & Evaluation of Nutrition of the first generation method, and of the defect in not reflect the ecological effects of eutrophication,which are still the first choice of the Xiangshan-Bay's eutrophication evaluation methods based on the ecological environment data in Xiangshan-Bay at the present stage.The results of the research is of great significance to the correct understanding of the eutrophication status of the Xiangshan-Bay marine's water,promoting and improving the research level of eutrophication in the Xiangshan-Bay marine's water, protection and maintenance of Xiangshan-Bay's ecological health and sustainable development.