中文摘要：

珠江河口区具有三江汇流、八门入海的复杂河网，水动力条件存在多种不确定性，加之河口区水资源系统受快速城市化、河口挖沙与河道整治、上游水利工程调度、海平面上升等多重因素影响，盐水入侵现象异常复杂。选取磨刀门水道广昌站近10年来（2001-2011年）枯水期逐日及逐时盐度序列，应用小波分析方法，研究了珠江河口区-磨刀门水道盐度序列多时间尺度周期特征。研究结果表明：磨刀门水道盐度变化周期特征与潮汐周期特征一致，存在明显的日周期（24．6h）、半月周期（14．8d）及不明显的半日周期（12．3h）、月周期（30d）。

英文摘要：

The Pearl River Estuary contains a complex river network which characterizes the confluence of the three rivers in the Pearl system and the eight waterways to the sea. Hence, distinct uncertainties exist within the hydrodynamic force. Additional elements, for instance, fast urbanization, estuary sand excavation, river realignment, hydraulic engineering and sea level rise contribute to the salt water intrusion in water resource system located in estuary area for its extreme complexity. In this paper, the data of daily and hourly salinity sequence in dry season for the last 10 years （2001-2011 ） from Guangchang Station in the Modaomen Waterway are studied by using wavelet analysis. The result shows that consistence truly exists in the periodic features between salinity changes in the Modaomen Waterway and the tide. The day period （24.6 h） and half-month period （14.6 d） are evident, while the half-day period （12.3 h） and month period （30 d） not obvious.