Multiple choice What is the study of groundwater in the soil and rocks of the Earth's crust called? Hydroinformatics Ecohydrology Isotope hydrology Flownet Hydrogeology Reveal answer Fill a bubble to check yourself E Correct answer Explanation 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).