三峡水库草堂河营养状态变化特征与影响因素分析  

Change Features and Influencing Factors of Trophic States of the Caotang River in Three Gorges Reservoir

作　　者：张永生[1,2] 李海英 吴雷祥[1,2] ZHANG Yongsheng;LI Haiying;WU Leixiang(China Institute of Water Resources and Hydropower Research,Beijing 100038,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,Beijing 100038,China)

机构地区：[1]中国水利水电科学研究院,北京100038 [2]流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《生态环境学报》2020年第10期2060-2069,共10页Ecology and Environmental Sciences

基　　金：国家重点研发计划子课题(2017YFC0403503);国家自然科学基金面上项目(5187091516);国家水体污染控制与治理科技重大专项(2014ZX-006-05)。

摘　　要：为了解三峡水库重点支流草堂河的营养状态及影响因素,于2017年7月-2018年6月在长江设置2个断面,在草堂河设置4个断面,在各断面处监测水体透明度,并采集长江和草堂河各断面处水样,在实验室内监测水体内叶绿素a、CODMn、总氮和总磷浓度,利用综合营养指数法分析了长江和草堂河营养状态的周年变化,讨论了营养盐变化的影响因素。研究结果如下:长江和草堂河叶绿素a浓度表层>中层>底层,2017年8月CT03断面表层水体叶绿素a的浓度最高达到19.56 mg·L^−1。CODMn浓度平均值在0.98-2.62 mg·L^−1之间,空间上CODMn浓度差异不显著(P<0.05),除2017年9月其他时间各断面CODMn浓度均低于4 mg·L^−1。各监测点位TN浓度平均值均在2.0 mg·L^−1左右,垂向TN浓度均值无明显差异。草堂河TP浓度季节性变化较大,年度平均值在0.08-0.30 mg·L^−1之间,高于长江水体TP浓度。草堂河水体透明度平均值在1.79-1.98 m之间,长江干流的透明度平均值约为2.20-2.30 m,长江透明度高于草堂河的透明度。长江综合营养状态指数(TLI)为28.26-42.63,蓄水期综合营养盐指数较低,枯水期营养状态指数较高;草堂河综合营养状态指数为41.23-50.28,大部分时间呈现中营养状态,仅在2017年8月综合营养状态指数较高,约为56.41,草堂河综合营养状态从上游到下游逐渐降低,综合营养状态季节变化冬季<春季<秋季<夏季。In order to clean the trophic states of the Caotang River in Three Gorges Reservoir,two points in Yangtze River and four points in Caotang River were set from July 2017 to June 2018.Water transparency was monitored and water samples collected in the six points.Four nutrient indexes of water were also monitored in the laboratory,such as Chal-a,CODMn,TN,TP and water transparency.In the research,the annual change of trophic states was analzed with comprehensive nutrition index method,and its influencing factors were discussed.The results were as followed:Chal-a concentration was maximum in surface layer and minimum in bottom layer not ony in Yangtze River but slao in Yangtze River.In August 2017,Chal-a concentration was 19.56 mg·L^−1 in surface layer at CT03.Mean concentration of CODMn was from 0.98 mg·L^−1 to 2.62 mg·L^−1 during the period of monitoring,and it was not significant difference among water layers,it was under 4mg·L^−1 at every point except September 2017.Mean concentration of TN was about 2.0 mg·L^−1,and it was not significant difference in vertical direction of water.TP concentration seasonal changed was greatly,it was from 0.08 mg·L^−1 to 0.30 mg·L^−1,TP concentration in Caotang River was higher than its in Yangtze River.Water transparency average was form 1.79 m to 1.98 m in Caotang River,but it was form 2.20 m to 2.30 m in Yangtze River.TLI in Yangtze River was from 28.26 to 42.63,it was lower in storage period,and higher in drought period;TLI in Caotang River was from 41.23 to 50.28,the water was mesotrophic state in most of the year,only in August 2017,the water was eutrophication state,TLI was 56.41.TLI reduced gradually from upstream to downstream in Caotang River,it was minimum in winte,and maximum in summer.

关 键 词：三峡水库 草堂河 营养状态 综合营养指数法 影响因素 

分 类 号：X52[环境科学与工程—环境工程]