China on Monday launched its annual effort to remove sediment from the Yellow River, China's second largest, ahead of flood season.

The operation began on Monday morning with water discharged from the three gates of the Xiaolangdi reservoir in central China's Henan Province. The operation will last about 17 days, and will remove an estimated 100 million tons of mud and sand from the river.
The Yellow River picks up 1.6 billion tonnes of fine sediment, or loess, when it flows through China's Loess Plateau region. It carries more sediment per cubic meter than any other major river in the world, and deposits most of it long before it reaches the delta.
The removal of sediment is a crucial measure to keep the river channel open.
During the sediment removal operation, three major reservoirs in the middle reaches of the Yellow River, the Wanjiazhai, the Sanmenxia and the Xiaolangdi, will coordinate water discharges to wash away the sediment in the river.
"By coordinating regulation across both mainstream and tributary reservoirs, we aim to maintain the downstream river's flow capacity, reduce sediment buildup in reservoirs, and improve ecological conditions in the lower reaches of the Yellow River," said Ren Wei, an official from the Yellow River Conservancy Commission.
China has performed the sediment removal operations 29 times, flushing 3.5 billion tons of sediment from the Yellow River into the sea. These efforts have slowed the narrowing of the river's main channel downstream and significantly improved downstream flooding and the river’s overall ecology.