From hydro- +‎ -ology.

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• Rhymes: -ɒlədʒi

hydrology (usually uncountable, plural hydrologies)

1. The science of the properties, distribution, and effects of water on a planet's surface, in the soil and underlying rocks, and in the atmosphere.
2. The properties, distribution, and flows of water in a specific locale; the hydrological characteristics of a particular place or region.
   • 1883, George Robert Bowen Steane, Transactions of the Royal society of Victoria‎^[1], Notes on Hydrology, page 96:

     Excessively high floods may be caused by obstructions which were not noted by the observer subsequently removed. Information of this kind is necessary, but it is equally necessary that something of the local hydrology should be also known and applied.

   • 1991, John Francis DeGeorge, Development of a Computer-aided Support System for Water Resources Simulation:

     Operations studies are required to define appropriate hydrologies and facility operations schedules on which to base the Delta modeling.