Hydrology is science of the behavior of water in the atmosphere, on the Earth’s surface, and in the subsurface, while the hydrogeology studies the groundwater and its relationship to the geologic environment. Both points of view are important in a site investigation and assessment. Basic in hydrology is the hydrologic cycle, also known as the water cycle, i.e. the continuous circulation of water between the atmosphere, land, surface water, groundwater, and plants, through condensation, precipitation, runoff, infiltration, evaporation, transpiration, groundwater flow, storage and seepage.
shows the elements of the hydrologie cycle. The hydrologie cycle supplies terrestrial organisms with freshwater and is therefore a source of life. The system powered by solar radiation determines essentially the climate.