If you are trying to manage it, you must first divide your area of concern into drainage basins.

In the Hai river basin in China, for example, deep-groundwater tables have dropped by up to 90 metres.

Europe seems to have been the hot spot, with a whopping 80 new species emerging in the Mediterranean Basin.

Though her species survives, the genetically distinct Columbia Basin population to which she belonged does not.

I first went to the Amazon basin in 1974. At that time it was a real wild-west.