hydrogeology
noun
hy·dro·ge·ol·o·gy ˌhī-drō-jē-ˈä-lə-jē 
: a branch of geology concerned with the occurrence, use, and functions of surface water and groundwater
also : the phenomena dealt with in hydrogeology
hydrogeologist
ˌhī-drō-jē-ˈä-lə-jist
noun 
Example Sentences
Recent Examples on the Web Famiglietti is a hydrologist and director of the Global Institute for Water Security at the University of Saskatchewan, where Ferguson is an associate professor focusing on hydrogeology. 
Ian James, The Arizona Republic, 28 Apr. 2021 Consider an example from a science that generates few partisan arguments: hydrogeology. Scott K. Johnson, Ars Technica, 13 Apr. 2020
Ian James, The Arizona Republic, 28 Apr. 2021 Consider an example from a science that generates few partisan arguments: hydrogeology. Scott K. Johnson, Ars Technica, 13 Apr. 2020 Word History
First Known Use
1824, in the meaning defined above