Water levels on the Rhine river are very low because of unusually hot and dry weather, preventing many vessels from navigating the critical European shipping route fully loaded. Flowing from the Swiss Alps to the North Sea via German industrial heartlands, the Rhine is a major route for products ranging from grains to chemicals and coal. It is an important link between industrial producers and global export terminals in North Sea ports such as Rotterdam and Amsterdam, while canals and other rivers link the Rhine to the Danube, making it possible to ship to the Black Sea as well. When water levels fall, cargo vessels have to sail with reduced load to prevent them running aground