径潮共同作用对径流型河口盐水上溯的影响  

Combined influences of runoff and tide on saline intrusion length in riverine estuary

作　　者：尹小玲[1] 赵雪峰[1] YIN Xiaoling, ZHAO Xuefeng(School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, Chin)

机构地区：[1]华南理工大学土木与交通学院,广东广州510641

出　　处：《水科学进展》2018年第1期118-126,共9页Advances in Water Science

基　　金：国家自然科学基金资助项目(11572130)~~

摘　　要：为进一步认识径流型河口枯季盐水上溯距离变化的影响因素及其作用机制,将实际河口简化并在不同径流量下分别用等潮差正弦潮和主要分潮驱动,进行盐水三维数值模拟试验。结果表明:随着径流和潮汐两大基本作用的相对强度不同,平衡态下盐水形态和位置自动调整并最终达到盐输运平衡,径流量小于3 000 m3/s且潮差小于2 m时,最大上溯距离随潮差的变化规律在不同径流量下存在明显差别;大小潮半月周期内盐水呈现非平衡态,非强混合时潮周期盐水上溯最大距离围绕平衡态随潮差呈顺时针绳套关系变化。径流导致的密度环流作用和潮汐的混合作用交织,两者相互影响并协同发展,两种作用相对强度的不同是导致径流型河口盐水上溯距离变化显著的主导因素。In order to further understand the leading influential driving forces and their cooperative mechanism in saltwater intrusion of riverine estuaries in dry season,3-D numerical simulation experiments were conducted in this study with a simplified estuary which was forced by sinusoidal tides of constant tidal ranges and main tidal constituents respectively at different runoff flow. The results indicate that in tidal saline equilibrium,with variation of relative strength of the runoff and tide,the shape and the location of salt water intrusion are automatically adjusted and end with balanced salt transportation. When the runoff rates are less than 3 000 m3/s and tidal ranges less than 2 m,there are obvious differences in the variability of maximum intrusion lengths with tides under different runoff flow. For weak mixing estuary,during the period time of spring and neap,the saline water presents fortnight non-equilibrium and their data points of tidal maximum intrusion length with respect to tidal range change clockwise like a loop around that of the equilibrium state. The density circulation induced by runoff and the tidal mixing collaborate and develop with interaction. The contrast of their intensity dominates the significant distinction of saline intrusion length in riverine estuaries.

关 键 词：河口盐水上溯 密度环流 径潮共同作用 数值试验 

分 类 号：TV133.2[水利工程—水力学及河流动力学]