极端干旱下长江口咸潮入侵成因及压咸补淡措施
Causes analysis of saltwater intrusion in Yangtze River Estuary during extreme drought and countermeasures
陈致远 1吴敬文 2乔红杰 2陈鹤翔 1金光球1
作者信息
- 1. 河海大学 水利水电学院,江苏 南京 210098;河海大学 水灾害防御全国重点实验室,江苏 南京 210098
- 2. 长江水利委员会水文局 长江口水文水资源勘测局,上海 200136
- 折叠
摘要
2022 年长江上游遭受极端干旱,长江口咸潮入侵加剧,区域用水安全受到严峻考验.为探究极端干旱天气下咸潮入侵成因和应对策略,基于长江口2019～2023 年枯水期的实测盐度、潮水位、风速风向数据与同期上游大通站径流量数据,采用Spearman相关性分析、卡方分析等方法,分析了2022 年9 月起长江口咸潮入侵过程与长江口咸潮入侵的主要影响因素.分析结果显示:①2022 年8 月起长江干流枯水期提前,叠加台风和天文大潮情况,使得2022 年9 月至2023 年4 月长江口地区崇明洲头站、杨林站和六滧站的盐度大幅超标,分别达到1.922‰,0.585‰和2.134‰.② 长江口 3 个主要盐度监测站点受上游来水影响时间存在前后差异,在大通站流量低于15 000 m3/s时,不同站点所属区域发生了不同程度的咸潮入侵情况.③2022 年10 月的压咸补淡措施在小潮期间作用于长江口地区,使得大通站流量高于12 000 m3/s,在南支上半段产生较好的压咸效果.研究成果可为长江口流域不同地区咸潮上溯成因分析和压咸补淡应对策略提供参考.
Abstract
In 2022,the upper reaches of the Yangtze River suffered extreme drought,and the saltwater intrusion in the Yangtze River Estuary(YRE)was intensified,leading to a severe test on regional water security.To investigate the causes and counter-measures of saltwater intrusion under extreme drought,this paper analyzed salinity,tide level,wind speed and direction data during low water periods between 2019 and 2023,as well as runoff data from upstream Datong Station during the same period.Spearman correlation analysis and Chi-square analysis were employed to examine the process of saltwater intrusion in September 2022 and identify key influencing factors.The analysis results revealed that:① Due to extreme drought,the dry conditions of the main stream of the Yangtze River advanced to August 2022.Combined with typhoons and astronomical spring tides,the salinity of Chongmingzhoutou Station,Yanglin Station and Liuyao station in the YRE greatly exceeded the limit from September 2022 to April 2023,reaching 1.922‰,0.585‰ and 2.134‰.②The three salinity monitoring stations located in the YRE experienced varying degrees of saltwater intrusion based on their respective upstream incoming water conditions.When the discharge at Datong Station fell below 15 000 m3/s,different regions along the estuary would be affected by saltwater intrusion accordingly.③ In October 2022,recharging fresh water for repelling saltwater intrusion were implemented during neap tide periods within the YRE.These measures resulted in an increase of discharge at Datong Station to over 12 000 m3/s after water replenishment and effectively com-pressed saline levels in the upper part of the southern branch.These findings provide theoretical support for analyzing factors con-tributing to saltwater intrusion across various areas within the YRE,and developing strategies for managing recharging fresh water for repelling saltwater intrusion.
关键词
咸潮入侵/盐度/径流量/潮差/压咸补淡/长江口Key words
saltwater intrusion/salinity/streamflow/tidal range/recharging fresh water for repelling saltwater intrusion/Yan-gtze River Estuary引用本文复制引用
基金项目
国家自然科学基金(U2040205)
国家重点研发计划(2022YFC3202602)
出版年
2024
国家科技期刊平台
NSTL
万方数据