摘要
潮汐河口几何形态与潮量间呈幂函数关系,具有分形特征。本文基于分形理论并考虑量纲和谐,以相对潮量作为观测尺度度量相对过流面积,以相对单宽潮量度量相对水深,建立了潮汐河口相对过流面积—相对涨(落)潮量和相对水深—相对单宽涨(落)潮量的水力几何形态关系式,后者适用于没有横断面概念的开敞海域。据此确定了椒江河口与瓯江河口的水力几何形态关系式。结果表明,本文公式适用性良好,水力几何形态分维值表征了河口的稳定性及涨、落潮水动力作用的相对强弱:处于相对稳定期的河口,分维值接近1,涨、落潮时水动力作用强的时段分维值更接近1。本文研究结果可为河口治理、航道疏浚等工程提供理论依据。
Hydraulic geometry and tidal volume in tidal estuaries display a relationship of power function and are characterized by fractal dimensions. This paper describes hydraulic geometry of tidal estuaries using the fractal theory and the principle of dimensional homogeneity, along with two in-situ observable indicators： the relative volume of flood or ebb tide for relative cross-sectional areas, and the relative volume of flood or ebb tide per unit width for relative water depths. Formulas have been developed for the relationships of these two indicators versus relative cross-sectional area and relative water depth respectively, both applicable to regular estuaries, but the latter one is also applicable to those open seas of which no cross-section can be defined. In a case study of the Jiaojiang estuary and Oujiang estuary, the parameters in these two formulas of hydraulic geometry were determined using the data of field observation, and the results indicated a fairly good accuracy of the formulas. Fractal dimensions of hydraulic geometry reflect the stability of an estuary and the relative effects of its hydrodynamic conditions during flood tide and ebb tide, and their values will be closer to 1.0 if it is relatively stable or its hydrodynamic forces are stronger. The results would lay a theoretical basis for further studies on estuary evolution and channel design and regulation.
出处
《水力发电学报》
EI
CSCD
北大核心
2016年第8期56-64,共9页
Journal of Hydroelectric Engineering
基金
教育部博士点基金资助项目(2120101110108)
浙江省水利厅重点项目(RB1212)
关键词
水利工程
水力几何形态
分形理论
分形维数
椒江河口
瓯江河口
河口稳定性
hydraulic engineering
hydraulic estuary
Oujiang estuary
stability of estuary geometry
fractal theory
fractal dimension
Jiaojiang
