Canadian photographer Benoit Aquim has won the first Prix Pictet, said to be the wordâ€™s richest photographic prize at 100,000 Swiss francs (Â£50,000; $90,000).
The Prix Pictet, sponsored by the Swiss bank Pictet et Cie, aims to foster environmental awareness and this yearâ€™s theme is about water.
Aquim in fact took the absence of water as his subject. He traveled to northern China to document an ecological disaster which is turning 400,000 square km of once-fertile farmland into desert.
His photographs depict people struggling in arid streets and landscapes against the dust storms which blow almost constantly in the affected area.
Photo: Benoit Aquim/Prix Pictet