Rivers meander. Lakes grow and shrink. Engineers build dams and farmers flood fields.

In the 30-year animation* above, Bangladesh’s Brahmaputra River sweeps unpredictably across the landscape. Much of the world’s water is in constant motion.

Scientists with the European Commission’s Joint Research Center in Ispra, Italy, working with Google engineers, have used millions of satellite images to illustrate how rivers, lakes and other bodies of water have changed over three decades.

The project, which is freely available, will allow researchers to improve climate models and find evidence of the effects of climate change around the world. But even the untrained eye can see the results of drought in the Western United States, for example, or of warming temperatures in the high country north of the Himalayas.