关键词: 西凉湖, 沉积物, 重金属, 营养元素, 有机质, 分布特征, 污染评价

Abstract: Taking Xiliang Lake as the research object, the pollution of heavy metal elements was evaluated by the geo-accumulation index method and the potential ecological risk index method, and the pollution of nitrogen, phosphorus and organic matter was evaluated by the comprehensive pollution index method and the organic pollution index method. The results showed that the overall level of heavy metal pollution in the sediment of Xiliang Lake was relatively low, and the spatial distribution of Cu, Zn, As and Hg heavy metal elements was similar. A few points showed moderate or severe pollution of Cd, Ni and Hg elements, which was attributed to aquaculture feed and transportation. In the assessment of nitrogen and phosphorus pollution in the sediment of Xiliang Lake, it was found that phosphorus pollution was relatively low, with a moderate pollution level at 80% of the points; the nitrogen pollution situation was severe, and all points had reached severe pollution. All points in the comprehensive evaluation of nitrogen and phosphorus elements had reached severe pollution. The evaluation results of the organic pollution index method showed that the organic pollution index at all points was greater than 0.5, reaching the level of severe pollution. Based on the evaluation results of nitrogen and phosphorus elements, the external pollution was attributed to the nutrient input caused by the excessive development of fisheries in Xiliang Lake.

Key words: Xiliang Lake, sediments, heavy metals, nutrient elements, organic matter, distribution characteristics, pollution assessment