滇池草海水体枯水期不同形态氮磷空间分布差异性

Spatial Distribution Difference of Different Forms of Nitrogen and Phosphorus in Caohai Lake in Dianchi Lake during Low Water Period

根据2016年11月滇池草海空间16个测点TN、TP、DTN、DTP、蓝藻密度分析结果,研究了草海水体不同形态氮磷、蓝藻密度的空间分布特征、草海水体的富营养化特征、各指标之间的相关性和各监测点水环境相似性。结果表明:草海TN平均浓度值3.54mg/L,超地表水Ⅴ类标准,TP平均浓度值0.096mg/L,达到地表水Ⅳ类标准,DTN和PP为氮、磷的主要形态。TP、TN浓度的空间分布呈现由北向南逐渐降低随后升高的趋势。蓝藻密度的空间分布呈现随水流方向由北向南逐渐升高,DTN、DTP浓度的空间分布呈现随水流方向由北向南逐渐降低的趋势。采用K-means聚类分析方法将采样点划分为3组,蓝藻密度与TN和DTP呈显著相关性,磷可能是限制性营养盐。

Based on the analysis results of TN,TP,DTN,DTP and cyanobacteria density at 16 stations in Caohai of Dianchi Lake in November 2016,the spatial distribution characteristics of different forms of nitrogen and phosphorus,cyanobacteria density,eutrophication characteristics of the Caohaiwaterbody were studied as well as the correlation between these indicators and the similarity of water environment at each monitoring point.The results showed that the average TN concentration was 3.54mg/L,exceeding Class V Standard of Surface Water,and the average TP concentration was 0.096mg/L,which met Class IV Standard.DTN and PP were the main forms of nitrogen and phosphorus.The spatial distribution of TP and TN concentration decreased gradually from north to South and then increased.The spatial distribution of cyanobacteria density increased gradually from north to south along with the flow direction,and the spatial distribution of DTN and DTP concentration decreased gradually from north to south along with the flow direction.K-means cluster analysis was used to divide the sampling points into three groups.The density of cyanobacteria was significantly correlated with TN and DTP.Phosphorus might be a limiting nutrient.