Studies and thinking on key issues related to water and sediment control in the Pearl River Estuary

Yuan Fei; Hu Xiaozhang; Yu Fenghua; Lu Chen

doi:10.3969/j.issn.1000-1123.2025.06.004

Abstract：Pearl River Estuary,located at the end of the Pearl River,shall be the core of urban agglomeration of the Guangdong-Hong Kong-Macao Greater Bay Area,with functions of flood discharge,tidal control,water supply,ecology,port and navigation.Intensive human activities may lead to decrease of sediments from upstream,downcutting of rivers,change of river bank and course patterns,disruption of water sediment balance and threaten water security.Based on review of Pearl River Estuary harnessing process,present status and existing problems of water and sediment are analyzed,which are mainly reflected in three aspects.First,large-scale imbalance of West and North Rivers has changed the diversion ratio of Sixianjiao,increasing the pressure of flood control in the north of Northwest River Delta.Second,affected by changes of coming water and sediment upstream and human activities,sandbar at the mouth of the Modaomen River has shrunk,and seawater intrusion has intensified.Third,large-scale sand mining in Lingdingyang has changed the sand and river course pattern that affect operation of ports and waterways in the coastal areas.Hydrodynamic control shall be employed to facilitate adaptive restoration of the estuary,so as to adjust water-sediment relationship.First,diversion ratio should be stabilized by combining ecological and structural measures at the apex of the estuary in Sixianjiao.Second,artificial enclosure should be conducted at the forefront of the river mouth for siltation at the Modaomen sandbar.Third,natural restoration should be maintained for long-term stability of sand mining area in Lingdingyang,in order to rebuild favorable water and sediment conditions and ensure water security of the Pearl River Estuary.