南水北调中线总干渠叶绿素a与藻密度相关性研究

Study on correlation of Chlorophyll-a and Algal density in main canal of Middle Route of South-to-North Water Diversion Project

叶绿素a浓度和藻细胞密度是表征藻类生物量的两种不同方法。为了分析南水北调中线总干渠叶绿素a与藻密度的相关关系,在干渠内(动态条件)和干渠旁(静态条件)设置断面进行了采样,依据实测数据分析了叶绿素a和藻密度的变化情况及相关性。结果表明:动态条件下,叶绿素a浓度与藻密度的变化趋势基本一致,两者之间具有显著的相关性,相关系数为0. 88～0. 90;单一优势藻种水体中叶绿素a浓度与藻密度存在显著正相关性,r> 0. 95;优势藻种的更替变化会导致叶绿素a浓度与藻密度的相关性下降;动态条件转为静态条件时,空间和水文要素发生变化,将导致藻种、藻密度及叶绿素a浓度发生变化,并影响藻密度和叶绿素a浓度之间的相关性。研究成果有利于有关部门掌握南水北调中线工程引水水质的变化,可为沿线用水户提供更好的服务。

The Chlorophyll-a concentration and Algal density can represent biomass of algal. In order to study the correlation between Chlorophyll-a concentration and Algal density in the main canal of Middle Route Project of South-to-North Water Diversion,the monitoring cross-sections were set in the main canal (dynamic condition) and stilling pool (static condition) beside the canal. The variation condition and correlation of Chlorophyll-a and Algal density were studied according to the monitored data. The results showed that in dynamic condition,the variation tendencies of Chlorophyll-a concentration and Algal density showed significant correlation,correlation coefficients were 0. 88 ~ 0. 90;Chlorophyll-a and Algal in water containing with single dominant specie had significant positive correlation,r > 0. 95;the change of dominant algal resulted in the decrease of correlation between Chlorophyll-a concentration and algal density;when dynamic conditions changed to static conditions,the changing spatial and hydrological factors influenced the correlation between Chlorophyll-a concentration and Algal density. The study results will help the relative departments to understand the water quality variation of diverted water by Middle Route Project of South-to-North Water Diversion and supply better service for water users along the route.