Hydrology - doodle

Today Google celebrates the Earthday^*with a cool hydrology doodle

Hydro-cycle with precip

Hydro-cycle

*
Earth Day is an annual day on which events are held worldwide to demonstrate support for environmental protection. Earth Day is observed on April 22 each year. Earth Day is now coordinated globally by the Earth Day Network, and is celebrated in more than 192 countries every year.^{( source: Wikipedia )}