Millions of tonnes of silt forced downstream through giant dam in China

These photographs may look like scenes from an apocalyptic film. But in fact they are of an annual operation to move 30 million tonnes of silt downstream a year in the Henan province. Bystanders holding umbrellas are dwarfed as they watch the tremendous rush of water gushing through gaps in a dam. It is part of a carefully-chorepgraphed operation to remove silt from the Yellow River in Luoyang. More than 390 million tonnes shifted this way over the last 13 years. The silt-carrying water gushes out of three specialised holes in the dam.

The Yellow River authority says the operation lowers the river bed in the lower reach of the river by an average of 2.03 meters each year.

The dam stands at 154m (505ft) tall and is 1,317m (4,321ft) wide. When it was built opened in 2000, following a six-year construction, it had cost US$3.5billion to construct.