摘要
为探究沙湖水体叶绿素a的时空分布特征及其与水环境因子关系,2015-2017年冬季(1月)、春季(4月)、夏季(7月)、秋季(10月)对沙湖水体叶绿素a含量和常规水环境因子进行采样与检测,分析沙湖叶绿素a含量与环境因子之间的相关性,通过逐步回归法和通径分析探讨了时空性变化对叶绿素a含量的影响。结果表明,沙湖叶绿素a季节变化明显,夏季最高,冬春两季相对较低,最大值出现在2017年7月(夏季),最小值出现在2015年4月(春季),2017年叶绿素a含量最高,年均值为18.94μg/L,空间分布也存在明显差异。相关分析表明,总磷(TP)、化学需氧量(CODCr)、五日生化需氧量(BOD5)和透明度(SD)是影响沙湖叶绿素a含量的主要环境因子;逐步回归分析表明,不同季节、不同采样点影响沙湖叶绿素a含量的环境因子存在差异,有机污染物与氮磷营养盐是主要的影响因子;通径分析表明,化学需氧量和总磷的总决定系数(dij)分别为0.379和0.373,是影响沙湖叶绿素a含量最主要的两个环境因子;其中总磷对沙湖叶绿素a含量的直接作用较大,是对叶绿素a起决定性作用的限定性营养盐。
Eutrophication of water bodies is a global problem and concern has been increasing at home and abroad.Chlorophyll-a(Chl-a)concentration is the primary means of evaluating the eutrophic status of lakes.Shahu Lake is the largest natural brackish lake in Ningxia Hui Autonomous Region.In this study,the spatial and temporal distribution of chlorophyll-a(Chl-a)and its relationship with the primary environmental parameters in Shahu Lake were analyzed.The objectives were to explore the eutrophication mechanism of Shahu Lake and provide a theoretical basis for improving lake water quality.Data on Chl-a and water quality parameters was obtained from samples collected at five sampling sites of Shahu Lake in January,April,July and October of 2015-2017.Correlation analysis was used to study the relationship between Chl-a concentration and water quality parameters.Stepwise multiple regression and path analysis were used to study the spatiotemporal changes in Chl-a concentration.Seasonal differences in Chl-a concentration were significant,with the highest levels in summer and lower levels during winter and spring.The maximum value occurred in July,2017and the minimum value occurred in April,2015.The highest average annual Chl-a concentration(18.94μg/L)was in 2017.The spatial distribution of Chl-a also varied significantly.Correlation analysis shows that total phosphorus(TP),chemical oxygen demand(CODCr),5-day biochemical oxygen demand(BOD5)and Secchi depth transparency(SD)were the environmental factors most associated with Chl-a concentration in Shahu Lake.Stepwise multiple regression shows that the effect of environmental factors on Chl-a concentration varied with season and sampling site.Organic pollutants(CODCr)and nutrients(TN,TP)were the main influencing factors.Path analysis shows that CODCrand TP were the two most important environmental factors affecting the spatial-temporal distribution of Chl-a concentration,with correlation coefficients of 0.379and 0.373,respectively.Among all of the environmental factors,TP had the
作者
杨子超
李延林
邱小琮
李世龙
郑灿
YANG Zi-chao;LI Yan-lin;QIU Xiao-cong;LI Shi-long;ZHENG Can(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,P.R.China;School of Life Science,Ningxia University,Yinchuan 750021,P.R.China)
出处
《水生态学杂志》
CSCD
北大核心
2020年第2期77-82,共6页
Journal of Hydroecology
基金
宁夏高等学校一流学科建设(水利工程)项目(NXYLXK2017A03)
宁夏重点研发计划(东西部科技合作)项目“沙湖水质改善与生态功能提升技术研究与示范”(2017BY087)。
关键词
沙湖
叶绿素A
环境因子
逐步回归法
通径分析
Shahu Lake
chlorophyll-a
environmental factors
stepwise multiple regression
path analysis
