|Title of host publication||Encyclopedia of Lakes and Reservoirs|
|Place of Publication||United Kingdom|
|Pages||608 - 616|
|Number of pages||9|
|Publication status||Published - 2012|
Lakes are formed when depressions are filled with water. Reservoirs are artificial lakes created behind a dam or between dykes. There are nearly nine million lakes in the world with a total surface area of about 1,600,000 km2 and a total volume of 230,000 km3.