“十三五”期间阳宗海富营养化状态评价及其变化特征分析

Evaluation of Eutrophication Status and Analysis of Its Variation Characteristics in Yangzonghai Lake during the 13th Five-Year Plan Period

基于“十三五”期间(2016—2020年)阳宗海3个采样点位的pH、SD、TP、CODMn和Chla等理化指标例行监测数据,采用综合营养状态指数法对水体富营养化状态进行评价,借助Origin、ArcGIS和SPSS等软件,进行富营养化程度时空变化特征分析及Pearson相关性分析。结果表明,“十三五”期间阳宗海水体富营养化整体程度不高,营养分级为贫营养,但3个点位TP和TN浓度均值已接近或高于水华暴发阈值,存在潜在生态风险;时间变化上,阳宗海3个监测点位富营养化程度均呈现先上升后下降的趋势;空间变化上,阳宗海北部区域的富营养化程度相对较高,南部区域相对较低。Pearson相关性分析结果表明,阳宗海富营养化状态主要受TN和NH+4-N影响。

Based on the routine monitoring data of pH,SD,TP,CODMn and Chla at 3 sampling sites in Yangzonghai Lake during the 13th Five-Year Plan period(2016—2020),the eutrophication state of water was evaluated by comprehensive nutrition state index method,the spatial and temporal variation characteristics of eutrophication degree and Pearson correlation analysis were carried out with the help of Origin,ArcGIS and SPSS.The results showed that during the 13th Five-Year period,the overall degree of eutrophication in Yangzonghai Lake was not high,which was graded as poor nutrition.However,the average concentrations of TP and TN at the 3 sites were close to or higher than the water bloom threshold,potential ecological risks still exist;the eutrophication degree of the 3 monitoring points in YangzonghaiLake showed a trend of increasing first and then decreasing in terms of time change;in the change of space,the degree of eutrophication in the northern area of YangzonghaiLake was relatively high,and the southern area was relatively low.Pearson correlation analysis showed that the eutrophication status of YangzonghaiLake was mainly affected by TN and NH+4-N.