极端干旱条件下珠江口东江三角洲咸潮上溯响应规律研究  

Study on the response law of saltwater intrusion in the Dongjiang Delta of the Pearl River Estuary under extreme drought conditions

作　　者：杨芳 林中源 邹华志 朱磊 邹晓波 YANG Fang;LIN Zhongyuan;ZOU Huazhi;ZHU Lei;ZOU Xiaobo(Key Laboratory of Pearl River Estuary Regulation and Protection of Ministry of Water Resources,Guangzhou,China,510611;Pearl River Water Resources Research Institute,Guangzhou,China,510611;School of Marine Sciences,Sun Yet-sen University,Zhuhai,China,519082;Dongguan Water Affairs Bureau,Dongguan,China,523129)

机构地区：[1]水利部珠江河口治理与保护重点实验室,广东广州510611 [2]珠江水利科学研究院,广东广州510611 [3]中山大学海洋科学学院,广东珠海519082 [4]东莞市水务局,广东东莞523129

出　　处：《海洋通报》2023年第5期496-507,共12页Marine Science Bulletin

基　　金：国家重点研发计划(2021YFC3001000);广东省水利科技创新项目(2023-01);水利部重大科技项目(SKS-2022005)。

摘　　要：2021年珠江东江流域遭遇1956年以来最严重干旱,上游控制断面博罗站年均径流较多年平均减少了64.5%。在此极端干旱条件下,2021-2022年枯水期珠江口东江三角洲遭遇了有记录以来的最强咸潮上溯,严重威胁到区域供水安全。本文基于2009-2022年东江三角洲各水厂含氯度数据,利用交叉小波和小波相干分析识别了咸潮上溯与径流、潮汐、外海含氯度及海平面波动等影响因素间的相位关系与共变周期,揭示了极端干旱条件下东江三角洲咸潮上溯的主控因素及含氯度峰值交替变化的原因。研究发现,2021-2022年枯水期东江三角洲咸潮上溯主要影响因素为潮汐与伶仃洋湾内含氯度,其次为外海海平面波动,三种因素对东江三角洲咸潮上溯影响的时间尺度相互交织。5~9d的周期变化主要受外海海平面波动影响;14.8d的变化周期主要由大小潮及伶仃洋湾内含氯度控制;28~32d的周期变化主要影响因素为伶仃洋湾内含氯度。东江三角洲含氯度峰值交替变化的原因主要为伶仃洋湾内含氯度与潮汐间存在相位差(相关系数r=0.73,显著性水平P<0.01),并叠加外海海平面波动上升的影响(r=0.31,P<0.01)。本文可为东江三角洲咸潮预报及流域调度提供一定借鉴。In 2021,the Dongjiang River Basin of the Pearl River experienced the most severe drought ever since 1956.The average annual river discharge at the control section of Station Boluo in the upper reaches was 64.5%lower than the long-term mean value.Under the extreme drought conditions,the strongest saltwater intrusion in the Dongjiang Delta of the Pearl River Estuary ever recorded occurred in the dry season from 2021 to 2022,hence a serious threat to the security of the regional water supply.Based on the chlorinity data from 2009 to 2022 at the Dongjiang Delta,by cross-wavelet and wavelet-coherence analysis,we identified the phase relationship and covariant cycle between the saltwater intrusion and factors of river discharge,tide,offshore chlorinity,sea level fluctuation,to reveal the main controlling factors of the saltwater intrusion and explore reasons for the alternating variation of peak chlorine in the Dongjiang Delta under extreme drought conditions.The results show that the dominant factors of saltwater intrusion in the Dongjiang Delta during the dry season from 2021 to 2022 are tide and the chlorinity in the Lingdingyang Bay,followed by sea level fluctuation.The time scales of these three factors on saltwater intrusion are intertwined.The 5~9 d period of saltwater evolution was mainly affected by offshore sea level fluctuation,the variation period of 14.8 d was mainly controlled by the spring-neap tide cycle and the chlorinity of Lingdingyang Bay,and the main factor of the 28~32 d period was the chlorine in the Lingdingyang Bay.The main reason for the change of the peak value of chlorine in the Dongjiang Delta is the phase difference between the chlorine in the Lingdingyang Bay and tide(correlation coefficient r=0.73,significance level P<0.01),and combined action with the sea level fluctuation(r=0.31,P<0.01).This paper provides some reference to the prediction of saltwater intrusion in the Dongjiang Delta and basin scheduling.

关 键 词：东江三角洲 咸潮上溯 极端干旱 平均海平面 小波分析 

分 类 号：P731.1[天文地球—海洋科学]