潮汐汊口水流结构和动力特性研究
|
摘要
潮汐汊口作为河网的重要单元,关系到水沙以及可溶污染物、营养物质的输运和分配,对河口三角洲的水文过程、地貌沉积和生态环境,都有至关重要的影响。本文选取国内最大的珠江河网的分汊顶点-马口、三水分汊,基于一个大潮潮周期内走航ADCP测量,分析潮汐汊口各个支汊的流速过程及三维流速的时空分布特征;结合非稳态的调和分析算法和小波连续变换确定汊口处主要的潮汐组分,利用潮流分离技术,剥离出占主导作用的潮波信号并探讨潮波动力在潮汐汊口处的空间分布形态。研究发现,由于潮波在西江马口和北江三水汊道内传播的不对称性,两汊间的流速过程存在1.5 h左右的相位差。而连接西北江的岗根汊道,由于存在频繁的水体交换和弯道水流的特性,岗根断面的动力作用较为复杂,其最大垂向平均流速在涨落急时刻分别向左、右岸偏移,横向断面均出现了显著的顺时针二次流。
Tidal junction, as the fundamental unit of river network, is highly relevant to the transport and distribution of flow,sediment and soluble pollutants and nutrients. It plays an important role in ecological environment, hydrologic and depositional process of estuarine region. Based on the intra-tidal boat-mounted ADCP survey on the bifurcation of the Pearl River Network, the velocity process and spatial-temporal distribution of velocity were analyzed. The main tidal constitution was explored by NS Tide procedure and continuous wavelet analysis. The tidal constitution, furthermore, was separated from the flow signal. The results found that the velocity process in Sanshui lagged is about 1.5 h later than Makou due to asymmetry transport of tidal wave. Besides, the Ganggen tributary, the connecting channel of West and North River, displayed more complicated hydrodynamic characteristics due to frequent exchange of flow and curved channel. The maximum vertical-integration velocity tended to present at the left and right bank on the flood and ebb tide respectively. The cross-sectional distribution of flow structure at Ganggen displayed significant clockwise secondary flow at both flood and ebb tide.
Tidal junction, as the fundamental unit of river network, is highly relevant to the transport and distribution of flow,sediment and soluble pollutants and nutrients. It plays an important role in ecological environment, hydrologic and depositional process of estuarine region. Based on the intra-tidal boat-mounted ADCP survey on the bifurcation of the Pearl River Network, the velocity process and spatial-temporal distribution of velocity were analyzed. The main tidal constitution was explored by NS Tide procedure and continuous wavelet analysis. The tidal constitution, furthermore, was separated from the flow signal. The results found that the velocity process in Sanshui lagged is about 1.5 h later than Makou due to asymmetry transport of tidal wave. Besides, the Ganggen tributary, the connecting channel of West and North River, displayed more complicated hydrodynamic characteristics due to frequent exchange of flow and curved channel. The maximum vertical-integration velocity tended to present at the left and right bank on the flood and ebb tide respectively. The cross-sectional distribution of flow structure at Ganggen displayed significant clockwise secondary flow at both flood and ebb tide.
引文
Buschman F,Vegt V D M,Hoitink A,et al,2013.Water and suspended sediment division at a stratified tidal junction.Journal of Geophysical Research:Oceans,118(3):1459-1472.
Candela J,Beardsley R C,Limeburner R,1992.Separation of tidal and subtidal currents in ship-mounted acoustic Doppler current profiler observations.Journal of Geophysical Research,97(C1):769-788.
Chen Z,Pan J,Jiang Y,2016.Role of pulsed winds on detachment of low salinity water from the Pearl River Plume:Upwelling and mixing processes.Journal of Geophysical Research,121(4),2769-2788.
Geyer W R.1993.Three-dimensional tidal flow around headlands.Journal of Geophysical Research:Oceans(1978-2012),98(C1):955-966.
Geyer W R,Chant R,Houghton R,2008.Tidal and spring-neap variations in horizontal dispersion in a partially stratified estuary.Journal of Geophysical Research,113(C07023).
Lerczak J A,Rockwell G W,2004.Modeling the lateral circulation in straight,stratified estuaries.Journal of Physical Oceanography,34(6):1410-1428.
Luo X L,Zeng E Y,Ji R Y,et al,2007.Effects of in-channel sand excavation on the hydrology of the Pearl River Delta,China.Journal of Hydrology,343(3-4),230-239.
Sassi M G,Hoitink A,De Brye B,et al,2011.Tidal impact on the division of river discharge over distributary channels in the Mahakam Delta.Ocean Dynamics,61(12):2211-2228.
Seim H E,Gregg M C,1997.The importance of aspiration and channel curvature in producing strong vertical mixing over a sill.Journal of Geophysical Research:Oceans(1978-2012),102(C2):3451-3472.
Thomas R E,Parsons D R,Sandbach S D,et al,2011.An experimental study of discharge partitioning and flow structure at symmetrical bifurcations.Earth Surface Processes and Landforms,36(15):2069-2082.
Vermeulen B,Sassi M,Hoitink A,2014.Improved flow velocity estimates from moving-boat ADCP measurements.Water Resources Research,50(5):4186-4196.
Zhang W,Du J,Zheng J H,et al,2013.Redistribution of the suspended sediment at the apex bifurcation in the Pearl River Network,South China.Journal of Coastal Research,30(1):170-182.
陈静,王永学,2016.大连湾岸线变迁对海域水动力环境的影响.海洋通报,35(3):351-359.
崔欣梅,华锋,高大鲁,2011.台湾海峡夏季走航ADCP资料的滤潮处理.海洋科学进展,29(4):446-454.
高抒,2008.潮汐汊道形态动力过程研究综述.地球科学进展,23(12):1237-1248.
何为,2012.珠江河口分汊机制及其对排洪和咸潮上溯的影响.上海:华东师范大学.
刘杰,陈吉余,徐志扬,2008.长江口深水航道治理工程实施后南北槽分汊段河床演变.水科学进展,(5):605-612.
罗海超,1989.长江中下游分汊河道的演变特点及稳定性.水利学报,(6):10-19.
沈俊强,孙豪为,潘爱军,等.2016.基于夏季船载ADCP数据的台湾海峡西南部平均流与潮流特征的初步研究.热带海洋学报,35(3):11-19.
童朝锋,2005.分汊口水沙运动特征及三维水流数学模型应用研究.南京:河海大学.
姚志刚,鲍献文,李娜,等.2012.基于船载ADCP观测对罗源湾湾口断面潮流及余流的分析.海洋学报,34(6):1-10.
张芩,2000.船载ADCP资料的潮流分离技术.海洋通报,19(4):49-55.
周鸿权,孙昭晨,李伯根,等.2014.浙江象山港海域悬沙浓度分布变化及其水动力影响分析.海洋通报,33(6):694-702.
Candela J,Beardsley R C,Limeburner R,1992.Separation of tidal and subtidal currents in ship-mounted acoustic Doppler current profiler observations.Journal of Geophysical Research,97(C1):769-788.
Chen Z,Pan J,Jiang Y,2016.Role of pulsed winds on detachment of low salinity water from the Pearl River Plume:Upwelling and mixing processes.Journal of Geophysical Research,121(4),2769-2788.
Geyer W R.1993.Three-dimensional tidal flow around headlands.Journal of Geophysical Research:Oceans(1978-2012),98(C1):955-966.
Geyer W R,Chant R,Houghton R,2008.Tidal and spring-neap variations in horizontal dispersion in a partially stratified estuary.Journal of Geophysical Research,113(C07023).
Lerczak J A,Rockwell G W,2004.Modeling the lateral circulation in straight,stratified estuaries.Journal of Physical Oceanography,34(6):1410-1428.
Luo X L,Zeng E Y,Ji R Y,et al,2007.Effects of in-channel sand excavation on the hydrology of the Pearl River Delta,China.Journal of Hydrology,343(3-4),230-239.
Sassi M G,Hoitink A,De Brye B,et al,2011.Tidal impact on the division of river discharge over distributary channels in the Mahakam Delta.Ocean Dynamics,61(12):2211-2228.
Seim H E,Gregg M C,1997.The importance of aspiration and channel curvature in producing strong vertical mixing over a sill.Journal of Geophysical Research:Oceans(1978-2012),102(C2):3451-3472.
Thomas R E,Parsons D R,Sandbach S D,et al,2011.An experimental study of discharge partitioning and flow structure at symmetrical bifurcations.Earth Surface Processes and Landforms,36(15):2069-2082.
Vermeulen B,Sassi M,Hoitink A,2014.Improved flow velocity estimates from moving-boat ADCP measurements.Water Resources Research,50(5):4186-4196.
Zhang W,Du J,Zheng J H,et al,2013.Redistribution of the suspended sediment at the apex bifurcation in the Pearl River Network,South China.Journal of Coastal Research,30(1):170-182.
陈静,王永学,2016.大连湾岸线变迁对海域水动力环境的影响.海洋通报,35(3):351-359.
崔欣梅,华锋,高大鲁,2011.台湾海峡夏季走航ADCP资料的滤潮处理.海洋科学进展,29(4):446-454.
高抒,2008.潮汐汊道形态动力过程研究综述.地球科学进展,23(12):1237-1248.
何为,2012.珠江河口分汊机制及其对排洪和咸潮上溯的影响.上海:华东师范大学.
刘杰,陈吉余,徐志扬,2008.长江口深水航道治理工程实施后南北槽分汊段河床演变.水科学进展,(5):605-612.
罗海超,1989.长江中下游分汊河道的演变特点及稳定性.水利学报,(6):10-19.
沈俊强,孙豪为,潘爱军,等.2016.基于夏季船载ADCP数据的台湾海峡西南部平均流与潮流特征的初步研究.热带海洋学报,35(3):11-19.
童朝锋,2005.分汊口水沙运动特征及三维水流数学模型应用研究.南京:河海大学.
姚志刚,鲍献文,李娜,等.2012.基于船载ADCP观测对罗源湾湾口断面潮流及余流的分析.海洋学报,34(6):1-10.
张芩,2000.船载ADCP资料的潮流分离技术.海洋通报,19(4):49-55.
周鸿权,孙昭晨,李伯根,等.2014.浙江象山港海域悬沙浓度分布变化及其水动力影响分析.海洋通报,33(6):694-702.