基于探索性数据分析的汉丰湖富营养化驱动因子研究

为了探究汉丰湖富营养化驱动因子和营养状况,基于2014年水质监测数据,应用探索性数据分析方法初步研究了汉丰湖水动力条件与环境因子的相关性、水质主成分、相关环境因子熵权和营养健康指数。回归分析结果表明：水位与透明度呈正相关,流量与DO呈负相关,与流速呈负相关的因子为Chla、CODMn、NH+4-N和DTP;主成分分析提取的3个主成分分别反映了营养盐、有机污染以及藻类信息;DO、TN和TP的熵权表明汉丰湖水体的富营养状况受制于耗氧有机污染和氮、磷营养盐;营养健康指数S1>S3>S6（湖心）>S7（湖尾）>S5（湖首）>S4>S2。汉丰湖水体营养状况介于中营养到轻富营养,其中南河营养状态较高,湖心营养程度高于湖首和湖尾。减少有机污染物、营养盐的输入和改善局部水域的水动力条件可抑制藻类生长,有利于防治富营养化。 关键词： 探索性数据分析;汉丰湖;富营养化;驱动因子;水动力条件;主成分;熵权;营养健康指数

Research on Eutrophication Driven Factors of Hanfeng Lake Based on Exploratory Data Analysis

In order to study the eutrophication driven factors and its status in Hanfeng Lake, exploratory data analysis were applied to analyze the relationship between hydrodynamic conditions and environmental factors, the principal component of water quality, the related environmental factors of entropy weight and NHI (Nutritional Health Index ). The results of regression analysis show that a positive correlation between water level and transparency, and negative correlations among flow discharge and DO, Chla, CODMn, NH+4-Nand DTP; three principal component were extracted by Principal Component Analysis (PCA ), which represneted nutrients, organic pollutants and algaes, respectively. The entropy weights of DO, TN, TP show that the eutrophication status of Hanfeng lake were subjected to aerobic organic pollutants, nitrogen and phosphorus. The nutritional health index show that S1 ＞S3＞ S6(the center of lake) ＞S7(the tail of lake) ＞ S5(the head of lake) ＞ S4 ＞S2. In general, the eutrophication level of Hanfeng lake was ranged from mesotropher to light eutropher, with higher nutrient levels in South river, and higher nutrient in the center of lake when campare to the head and the tail of lake. In conclusion, reducing the input of organic pollutants and nutrient, and improving the hydrodynamic conditions of the local area are able to efficiently inhibit the growth of algae, which favors to the control of eutrophication.