Influencing Factors of Water Diversion Ratio for a Branching River-Network Estuary—A Case Study of Jiaomen Outlet, Pearl River Estuary

Abundant studies have been focused on the water diversion ratio for an estuary with limited branches and a conceptual branched estuary. However, little study has been concentrated on the branched river-network estuary, featured by multiple input and output branches. Digging deep into the water diversion ratio of such complicated estuaries is vital for flood security and navigation. The Jiaomen outlet of the Pearl River Estuary, connecting to the Humen Outlet with a lateral channel, is an ideal example for the exploration of the water diversion ratio of the branched river network. This study has carried out a series of flume experiments to investigate the water diversion ratio and the relevant influencing factors. The results show that the water diversion ratio correlates well with the relative flow velocity ratio of two adjacent outlets but is less affected by the absolute flow velocity magnitudes. The research results can shed light on the evolution of the branched river-network estuary.