钱塘江河口盐水入侵与影响因素的相关关系研究

Study on the Correlation between Saltwater Intrusion and Influencing Factors in Qiantang River Estuary

为定量分析中长时间尺度下钱塘江河口盐水入侵与其影响因素的相关关系,基于2000—2020年钱塘江河口的含氯度及径流、潮汐、江道地形等实测资料,采用偏相关分析方法,研究月时间尺度下七堡、仓前、盐官等3个观测站的含氯度与影响因素之间的相关关系,并拟合了七堡站含氯度的计算公式。结果表明:各站的含氯度与径流量呈负相关,与潮差、江道容积呈正相关,其中七堡、仓前的相关性较强,盐官站的相关性较弱;各站潮差与江道容积呈显著正相关,七堡、仓前站可达强相关,即江道变化对河口盐水入侵的影响可由七堡、仓前站潮差反映;七堡站月均含氯度、月最大含氯度可由其月均潮差、月最大潮差及上游月均径流量进行定量计算。研究成果可为钱塘江河口淡水资源利用提供参考。

Based on the measured data of salinity,runoff,tide,river channel topography at Qibao,Cangqian and Yanguan stations from 2000 to 2020,the partial correlation analysis method was used to study the correlation between the saltwater intrusion and the influencing factors in a monthly time scale,and the calculation formula of the salinity at Qibao station was fitted.The results show that the chlorinity of each station was negatively correlated with runoff,and positively correlated with tidal range and channel-storage capacity.The correlation at Qibao station and Cangqian station was strong,while the correlation at Yanguan station was weak.The tidal range of each station was significantly positively correlated with the channel-storage capacity,with Qibao station and Cangqian station reaching a strong correlation.The impact of river channel changes on saltwater intrusion in the estuary can be reflected by the tidal range of Qibao station and Cangqian station.The monthly average chlorinity and maximum chlorinity at Qibao station can be quantitatively calculated from their monthly average tidal range,monthly maximum tidal range,and upstream monthly average runoff.The research results can provide reference for the utilization of fresh water resources in the Qiantang River estuary.