人民长江2024，Vol.55Issue(2)：41-50,10.DOI:10.16232/j.cnki.1001-4179.2024.02.006
三峡水库水质时空变化特征及影响机制研究
Spatio-temporal variation characteristics and influence mechanisms of water quality in Three Gorges Reservoir
摘要
Abstract
The reservoir ecological environment after the construction and operation of the Three Gorges Project has been a great concern.The water quality conditions in the reservoir are complex and constantly changing.However,the spatio-temporal varia-tion characteristics and influence mechanisms of the water quality in the reservoir under the reservoir scheduling still need to be explored.Based on the monitoring data over 11 Yangtze River mainstream cross sections and 2 tributary cross sections in 2021,we utilized the water quality index(WQI)to evaluate the water quality in the reservoir,and combined principal component analysis(PCA),Pearson correlation analysis,one-way ANOVA and random forest(RF)methods to investigate the spatio-temporal characteristics and influence mechanisms of water quality in the Three Gorges Reservoir under the influence of reservoir schedu-ling.The results showed that:①From the spatial scale,the changes of each water quality parameter had obvious spatial heteroge-neity.The overall water quality condition had improved from upstream to dam site(Zhutuo to Wuxiakou section),and the water quality condition of Zhuyangxi section was the worst.②From a monthly perspective,different water quality parameters and WQI changed with reservoir storage.TP and CODMn concentrations generally showed the characteristics of flood season(June to Sep-tember)＞drawdown period(January to June)and storage period(September to October)＞high water level period(October to December).DO,pH and WQI,on the contrary,decreased in the drawdown period,were relatively stable in flood season,and gradually increased during the storage period.The ecological scheduling benefited the water quality in the reservoir.Two ecological schedules,from 29 May to 3 June and from 16 to 22 June,to promote the reproduction of drifting spawning fish,probably resulted in a significant improvement in water quality in the reservoir in June.④Various statistical analysis tools combined with RF meth-ods showed that there were significant correlations between different water quality parameters.TN,TP,NH3-N and CODMn were significantly positively correlated(r＞0.3,p＜0.01),pH and DO were significantly positively correlated(r =0.428,p＜0.01),and all parameters significantly affected the WQI in the Three Gorges Reservoir(p＜0.01),with turbidity being the most impor-tant parameter affecting the water quality in the Three Gorges Reservoir.The results of this study can provide a theoretical basis for the sustainable development of the water environment and the rational allocation of water resources in the Three Gorges Reser-voir.关键词
水质/水库调度/水质指数/随机森林/三峡水库Key words
water quality/reservoir operation/water quality index/random forest(RF)/Three Gorges Reservoir分类
资源环境引用本文复制引用
习文祥,祝贤彬,潘红忠,姚华明,刘明亮..三峡水库水质时空变化特征及影响机制研究[J].人民长江,2024,55(2):41-50,10.基金项目
智慧长江与水电科学湖北省重点实验室开放基金项目(ZH2102000113,ZH2002000113) （ZH2102000113,ZH2002000113）
湖北省教育厅科学技术研究计划青年人才项目(Q20211310) （Q20211310）
国家自然科学基金青年科学基金项目(41902257) （41902257）
