ABSTRACT
The presence of a single piezometric surface and unidirectional groundwater movement is typical of elementary and local Hydrogeological Systems (HGS). The types and detailed hydrogeological features of natural flows for HGSs with ground and artesian waters are presented in various publications. Watershed flows of volcanogenic extrusive rocks exhibit distinct heterogeneity and a complex pattern of groundwater movement. The lithosphere forms the upper solid envelope of the earth and consists of mineral matter, groundwater or other liquid components, free gases and living matter, with their inherent physical entities. Groundwaters are complex solutions consisting of molecules and dissociated ions of water, ions of other elements, colloidal particles, organic compounds, dissolved gases and suspended particles contained in the porous-fractured space of a geological body and existing in various aggregate states. A hydrogeological system comprises its own population of hydrogeological bodies characterised by determinate relations amongst themselves and between them and the environment.
