The Pearl River mouth can be divided into five sedimentation divisions ac-cording to hydraulic environments

types

sizes and ingredient of the sediment

as wellas sedimentation rate and topogrophy.Sandy sedimentation division of runoff type is anactivest locality of sedimentation function in the Pearl River mouth and in chief of riveraction。Muddy sedimentation division of tidal type is famouset of tidal action

and afaster sedimentation area for fine sediments in the modern river mouth is withstood byshelf-water.Sdimentation division of relict sand is a local corrosion

and by chief ac-tion of invasion and control of shelf-water。 Mixing sedimetation division of the modernriver mouth and mixing sedimentation division of the shelf’s shallow sea-relict sedimentare located between theabove-mentioned three sedimentation divisions; their hydrauliccondhions and sedimentation characters have the attributes of the transhional environ-ment.