长江中游通江故道水环境特征及其与浮游植物群落的关联分析  

Water Environment Characteristics and Its Association with Phytoplankton Communities of River-communicating Oxbow Lakes in Middle Reaches of the Yangtze River

作　　者：刘小光 柴朝晖 朱孔贤[1,2] LIU Xiao-guang;CHAI Zhao-hui;ZHU Kong-xian(Key Laboratory of River and Lake Regulation and Flood Control in the Middle and Lower Reaches of the Yangtze River of Ministry of Water Resources,Wuhan 430015,China;Changjiang River Scientific Research Institute,Wuhan 430015,China)

机构地区：[1]水利部长江中下游河湖治理与防洪重点实验室,湖北武汉430015 [2]长江水利委员会长江科学院,湖北武汉430015

出　　处：《长江流域资源与环境》2024年第7期1540-1549,共10页Resources and Environment in the Yangtze Basin

基　　金：国家自然科学基金项目(12302508,52320105006);中央级公益性科研院所基本科研业务费(CKSF2021438/HL,CKSF2021530/HL);开放基金(IWHR-SKL-KF202306,2021HLG02);水利技术示范(SF-202202)。

摘　　要：为了厘清长江中游通江故道水环境特征及其对浮游植物群落的影响,在汛前及汛后对长江中游通江故道进行了水环境及浮游植物调查,包括TP、TN、NH_(3)-N、COD_(Mn)、BOD_(5)等水质指标以及浮游植物的种类组成、生物量、生物多样性等。通过构建优化的模糊数学评价方法,对各故道水质状况及汛前汛后变化进行了量化评价,并对各故道富营养化状态进行评估,利用RDA分析与灰色关联分析探究了影响浮游植物群落特征的主要水质指标。结果表明:(1)各故道水质基本为III~IV,在汛前闸控通江故道水质要好于自然通江故道,在汛后则相反;(2)影响故道浮游植物密度的主要水质指标为TP与COD_(Mn),影响故道浮游植物群落多样性的水质指标主要为TN、NH_(3)-N与COD_(Mn);(3)建议通过营养盐阻控、水位控制与水动力调控等措施修复故道水质、优化浮游植物多样性与丰富度。To elucidate the aquatic environmental characteristics and their impact on phytoplankton communities in oxbow lakes situated within the middle reaches of the Yangtze River,investigations and analyses were conducted for both before and after the flood seasons.Water quality indicators encompassed TP,TN,NH_(3)-N,COD_(Mn) and BOD_(5).Phytoplankton investigations involved species composition,biomass,and biodiversity assessments.Significant indicators influencing lake water quality were identified,and a quantitative evaluation of water quality pre and post flood seasons was executed by constructing an optimized fuzzy mathematical evaluation method.Additionally,the eutrophication status of each lake was assessed.Grey relational analysis and RDA analysis were employed to pinpoint the primary water quality indicators impacting the characteristics of phytoplankton communities.Several key conclusions were drawn.(i)The water quality of oxbow lakes in the middle reaches of the Yangtze River generally ranged between III and IV.Lakes controlled by water gates exhibited better water quality in flood seasons than those freely connected to the Yangtze River,while the reverse was observed post-flood seasons.(ii)The primary water quality indicators influencing phytoplankton density were TP and COD_(Mn),while TN,NH_(3)-N,and COD_(Mn) were the main indicators affecting the diversity of phytoplankton communities.Oxbow lakes were typically in a mesotrophic state before flood seasons,and there was a slight increase in eutrophication for post-flood seasons.(iii)Implementing measures including nutrient control,water level regulation,and hydraulic control could aid in restoring lake water quality and optimizing phytoplankton diversity and richness.

关 键 词：长江中游 通江故道 水环境 浮游植物 模糊数学 

分 类 号：X524[环境科学与工程—环境工程]