In response to various technological and economic trends, geological survey organizations (GSOs) have increasingly relied on digital solutions to support the collection, maintenance, and distribution of subsurface geological data and information for use by increasingly diverse stakeholder communities. Raper (1989, 1991) provided some initial discussions of the applications and key concepts governing the development and applications of 3-D geological models. These efforts have been guided by the definition of the basic requirements for subsurface characterization and modeling first stated by Kelk (1991):

An understanding of the structural elements in the sub-surface is of great importance when establishing new constructions in bedrock, or surveying areas prone to rockslides. In this thesis the focus has been on combining methods within geology, structural geology, geophysics and engineering geology to reach an interdisciplinary understanding and predict sub-surface structures.

A chief goal of this book is to help the reader understand controls on the chemical quality of surfaceand subsurface-waters, both pristine and polluted. The focus is on inorganic processes and on the chemistry of soil and ground waters, with less said about the chemistry of precipitation, surfacewaters, or the ocean. The book leans heavily on the principles of chemical thermodynamics and the concept of chemical equilibrium. Chemical equilibrium, whether attainable or not, represents the reference state for purposes of explaining the concentrations of aqueous species in the hydrosphere. Concepts of chemical kinetics are introduced when they are known and seem applicable.  <...>