Abstract. The Minjiang River is the largest river in Fujian
Province. In 1993, the Shuikou Reservoir, which has an effective storage
capacity of 700 million m3, was built at about 161 km above the
estuary. The completion of the Shuikou Dam trapped most of the upstream
sediment in the reservoir area, resulting in a drastic decrease in sediment
in the lower reaches of the Minjiang River. The average annual sand load at
the Zhuqi Station (about 45 km below the dam) was reduced about 2∕3 after
the construction of the reservoir, from 7.42 to 2.55 million t by average, resulting in severe river bed downward cutting. At the same
time, the demand for the sand in Minjiang River channel is increasing year
by year. The amount of mined river sand is greater than the incoming
sediment deposited in the river, which intensified the downcutting of the
river bed. The downcutting leads to a continuous upward movement of the tide
limit in the river channel especially in the low-flow season. Meanwhile,
river embankments and river-related structures are damaged, and the
navigation capacity of the Minjiang River is reduced. At present, the river
bed of the lower Minjiang River is not yet stable, and the river regime is
in a state of constant adjustment.
Modelling the decadal dynamics of reach‐scale river channel evolution and floodplain turnover in CAESAR‐Lisflood
