1) Hydrology 
Hydrogeology (hydro- meaning water, and -geology meaning the study of the Earth) is the area of geology that deals with the distribution and movement of groundwater in the soil and rocks of the Earth`s crust (commonly in aquifers). The term geohydrology is often used interchangeably. Some make the minor distinction between a hydrologist or engine....
study of ground water
The geology of ground water, with particular emphasis on the chemistry and movement of water.The study of water levels in the ground.
hydrogeology 1. The science dealing with the occurrence and distribution of underground water. Also called hydrology and geohydrology. 2. The branch of geology that deals with the occurrence, distribution, and effect of ground water. 3. That branch of geology that studies the movement of subsurface water through rocks and the effect of moving wat...
The geology of ground water, with particular emphasis on the chemistry and movement of water. 
The science that deals with subsurface waters and geologic aspects of surface waters.
the science dealing with the occurrence and distribution of underground water. Also called