摘要
为预测不同径流过程影响下的盐水入侵强度,以长江口南支上段为研究对象,采用实测资料和理论分析相结合,建立了以大通流量和农历日期快速估算氯度值的经验模型。首先,以徐六泾实测潮位资料结合调和分析理论,在考虑11个主要分潮情况下证明日均潮差为半月周期函数,提出了用农历日期估算日均潮差的方法;其次,采用东风西沙实测氯度资料,选用不同函数形式,分析了以支汊盐水倒灌为主的情况下日均氯度对径流、潮差的量化响应关系;最后,提出了指数函数形式的氯度预测经验模型,模型计算值与实测值之间的决定系数在0.8以上。提出的经验模型可由大通流量快速估算特定位置的盐度,为相关的工程和规划研究提供了便捷途径。
To predict the intensity of saltwater intrusion under different riverine discharge,a new empirical model was developed to predict the chlorinity in the upper South Branch of the Yangtze River Estuary,where saltwater intrusion is strongly affected by tidal flow from the North Branch.In the model,only runoff at Datong station and lunar calendar date were required as variables.Firstly,the changes of daily mean tidal range was investigated with measuring data at Xuliujing.Using the theory of harmonic analysis with 11 main tidal components,it was proved that the daily mean tidal range changes every half-month.Thus,a new method was proposed to estimate the daily mean tidal range by using the lunar calendar.Secondly,the quantitative relationships between chlorinity and riverine discharge,tidal range were developed using the measured data at Dongfengxisha.Some functions in previous empirical models were examined to test their effectiveness under the condition of saltwater intrusion from the sub-branch channel.Finally,an empirical model was proposed in the form of exponential function to describe the chlorinity under different riverine discharge and tidal range conditions.The predicted chlorinity process at Dongfengxisha was in good agreement with the observations,with the correlation degree of up to 0.8.Using the proposed model in this study,intensity of saltwater intrusion at a certain location can be estimated with simple input data,which provides a convenient method to conduct prediction of saltwater intrusion.
引文
[1]唐建华,徐建益,赵升伟,等.基于实测资料的长江河口南支河段盐水入侵规律分析[J].长江流域资源与环境.2011,20(6):677-684.(TANG J H,XU J Y,ZHAO S W,et al.Research on saltwater intrusion of the south branch of the Changjiang Estuary based on measured data[J].Resources and Environment in the Yangtze Basin,2011,20(6):677-684.(in Chinese))
[2]茅志昌,沈焕庭,姚运达.长江口南支南岸水域盐水入侵来源分析[J].海洋通报,1993,12(3):18-24.(MAO Z C,SHEN H T,YAO Y D.Analysis of sources saltwater intrusion along south bank of south branch of Yangtze River Estuary[J].Marine Science Bulletin,1993,12(3):18-24.(in Chinese))
[3]茅志昌,沈焕庭,陈景山.长江口北支进入南支净盐通量的观测与计算[J].海洋与湖沼,2004,35(1):30-34.(MAO Z C,SHEN H T,CHEN J S.Measurement and calculation of net salt fluxes from the north branch into south branch in the Changjiang River Estuary[J].Oceanologia Et Limnologia Sinica,2004,35(1):30-34.(in Chinese))
[4]徐建益,袁建忠.长江口南支河段盐水入侵规律的研究[J].水文,1994(5):1-5.(XU J Y,YUAN J Z.The research on saltwater intrusion into the south branch of the Yangtze Estuary[J].Journal of China Hydrology,1994(5):1-6.(in Chinese))
[5]史英标,李若华,姚凯华.钱塘江河口一维盐度动床预报模型及应用[J].水科学进展,2015,26(2):212-220.(SHI Y B,LI R H,YAO K H.1-D movable bed numerical forecast model of salinity of the Qiantang River estuarine reach and its application[J].Advance in Water Science,2015,26(2):212-220.(in Chinese))
[6]肖成猷,朱建荣,沈焕庭.长江口北支盐水倒灌的数值模型研究[J].海洋学报,2000,22(5):124-132.(XIAO C Y,ZHU J R,SHEN H T.Study of numerical modeling about salt water flow backward in the Changjiang Estuary north branch[J].Acta Oceanologica Sinica,2000,22(5):124-132.(in Chinese))
[7]CAI H,SAVENIJE H,ZUO S,et al.A predictive model for salt intrusion in estuaries applied to the Yangtze Estuary[J].Journal of Hydrology,2015,529(3):1336-1349.
[8]SONG Z Y,HUAN X J,ZHANG H G,et al.One-dimentional unsteady analytical solution of salinity intrusion in estuaries[J].China Ocean Engineering,2008,22(1):113-122.
[9]SHAHA D,CHONNAM Y,KWARK M,et al.Spatial variation of the longitudinal dispersion coefficient in an estuary[J].Hydrology and Earth System Sciences,2011(15):3679-3688.
[10]PARSA J,AMIR E S.An empirical model for salinity intrusion in alluvial estuaries[J].Ocean Dynamics,2011,61(10):1619-1628.
[11]陈立,朱建荣,王彪.长江河口陈行水库盐水入侵统计模型研究[J].给水排水,2013,39(7):162-165.(CHENG L,ZHU J R,WANG B.The statistical model of saltwater intrusion at Chenghang Reservior in Yangtze Estuary[J].Water&Wastewater Engineering,2013,39(7):162-165.(in Chinese))
[12]郑晓琴,肖文军,于芸,等.基于径流和潮汐的长江口盐水入侵统计预测研究[J].海洋预报,2014,31(4):18-23.(ZHENG X Q,XIAO W J,YU Y,et al.Statistical prediction study of runoff and tide on Changjiang River saltwater intrusion[J].Marine Forecasts,2014,31(4):18-23.(in Chinese))
[13]诸裕良,闫晓璐,林晓瑜.珠江口盐水入侵预测模式研究[J].水利学报,2013,44(9):1009-1014.(ZHU Y L,YAN X L,LIN X Y.Study on prediction model of saline intrusion in Pearl River delta[J].Journal of Hydraulic Engineering,2013,44(9):1009-1014.(in Chinese))
[14]HORREVOETS A C,SAVENIJE H H G,SCHUURMAN J,et al.The influence of river discharge on tidal damping in alluvial estuaries[J].Journal of Hydrology,2004,294(4):213-228.
[15]路川藤,罗小峰,陈志昌.长江口不同径流量对潮波传播的影响[J].人民长江,2010,41(12):45-48.(LU C T,LUO X F,CHEN Z C.Influence of different runoffs on tidal wave propagation at Yangtze River Estuary[J].Yangtze River,2010,41(12):45-48.(in Chinese))
[16]陈尚渭,金兆森.长江潮位预报方法的研究[J].水利学报,1989(6):41-47.(CHEN S W,JIN Z S.The study about the method of tidal level forecast in Yangtze River[J].Journal of Hydraulic Engineering,1989(6):41-47.(in Chinese))
[17]杨振东,朱建荣,王彪,等.长江河口潮位站潮汐特性分析[J].华东师范大学学报(自然科学版),2012(3):112-119.(YANG Z D,ZHU J R,WANG B,et al.Analysis of tidal characteristics of the tidal gauges in the Changjiang Estuary[J].Journal of East China Normal University(Natural Sciences),2012(3):112-119.(in Chinese))
[18]关许为,顾伟浩.长江口咸水入侵问题的探讨[J].人民长江,1991,22(10):51-54.(GUAN X W,GU W H.The investigation of saltwater intrusion problem in Yangtze Estuary[J].Yangtze River,1991,22(10):51-54.(in Chinese))