hydrology

noun

1. (uncountable, usually)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. (uncountable, usually)The properties, distribution, and flows of water in a specific locale; the hydrological characteristics of a particular place or region.

   “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.”

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