珠江河口由河网及河口湾组成，横向汊道是维系河网乃至河口系统稳定的关键地貌单元，是径潮动力耦合的独特地貌结构，具独特的河口动力功能，其动力功能的自适应调整及稳态机制是典型的河口地貌动力研究的重要科学问题，也是研究河口水沙调控技术的关键。选取珠江河网4条横向汊道组成的体系作为研究对象，以余水位梯度的形成变化为切入点，基于新构建的一维余水位解析模型，结合数值模拟，分析不同径潮组合条件下复杂河网余水位的形成变化、余水位的自适应调整及潮波传播过程，揭示横向汊道的径潮耦合动力功能；采用复杂网络理论分析河网的连通性特征，进而采用数值方法模拟以口门围垦与河道采沙为代表的强人类活动对横向汊道动力功能的影响，揭示横向汊道以泄洪纳潮（水位调节）、潮能耗散（潮差调节）及径潮动力耦合与转换（径潮动力结构调节）为代表的动力功能的自适应调整及稳态机制，并为珠江河口的综合整治及水沙调控等提供科学依据。

The Pearl River estuarine system consists of the channel networks and the estuarine bays. It is noted that the transverse channels are the key morphological units that maintain the system stability as a result of its unique dynamic functions. Transverse channels are subject to the combined influence of both tide-river interaction and morphological processes. Thus, understanding their self-adaptive adjustment and homeostatic mechanism is essential for the morphodynamics study of the estuarine system and developing sustainable water managements in the river delta. In this study, on the basis of the development and variation of residual water level slope, the typical transverse channels system with 4 transverse channels are selected to explore the dynamics of residual water level, the self-adaptive adjustment of residual water level and tidal wave propagation under a wide range of tide-river conditions by means of the well-developed one-dimensional analytical model for residual water level and the numerical model. Based on the unravelling principle of tide-river interplay in complex channel networks, the connectivity characteristics of transverse channels are explored using a complex network theory. Subsequently, the impacts of human interventions, including land reclamation and sand excavation, on the dynamic functions (including the flooding discharge and tide via elevation adjustment, tidal energy dissipation via tidal range adjustment, and tide-river transmission via dynamic structure adjustment) of transverse channels are numerically simulated. Finally, the self-adaptive adjustment and homeostatic mechanism governing the dynamic functions of transverse channels in the Pearl River channel networks are provided, which is particularly useful for integrated regulations and sustainable water managements in the Pearl River estuary.