Strong tides are seen during the tenth-round silt-washing operation to clear up the sediment-laden Yellow River at the section of the Xiaolangdi Reservoir, north China's Henan Province, June 19, 2010. The operation, which will take 15 days to complete, will discharge speeding currents from the Xiaolangdi project on the lower reaches of the river with a maximum discharged water flow of 3,900 cubic meters per second. [Xinhua]