Dynamics of Subterranean Waters

an area of hydrogeology that examines the theoretical principles and methods for studying the quantitative patterns in the subterranean water balance and conditions. From the standpoint of the methodological constructs, which are based on filtration theory, the dynamics of subterranean waters is closely related to hydraulics and hydromechanics. The concept of the dynamics of subterranean waters is often, absent in foreign literature, and a large proportion of the questions related to it is studied by the hydrology of subterranean waters.

Many ideas of the dynamics of subterranean waters (concerning mainly the hydromechanical problems) were formed in the second half of the 19th century and the beginning of the 20th century by researchers who worked in hydraulics and theoretical mechanics—the French scientists H. Darcy and J. Dupuy, who established the linear law of filtration, and the Russian scientist N. E. Zhukovskii, who worked on the theory of movement of subterranean waters. The modern bases of the theory and methods of the dynamics of subterranean waters were created predominantly by Soviet scientists who worked in the 1920’s and 1930’s on the problems of hydraulic-engineering construction. N. N. Pavlovskii dealt with problems of the dynamics of groundwater in connection with hydraulic-engineering construction, and G. N. Kamenskii worked on problems of the relationship of the dynamics of subterranean waters to geological conditions, the questions of the movement of groundwaters in heterogeneous strata, and the methods of calculating the head of ground-water. Work on questions concerning subterranean petroleum hydraulics (gas hydrodynamics), which was established in the USSR by the works of L. S. Leibenzon, was also of great importance for the development of the dynamics of subterranean waters.

In the contemporary period, the active use of hydrodynamic calculations in almost all hydrogeological research has been characteristic. The development of procedures for the calculation of stationary filtration has been completed, and the theoretical principles for forecasting the head of groundwater in regions of hydraulic-engineering work and on irrigated land have been developed. Methods have been established for evaluating the exploitable reserves of subterranean waters, and the main trends of research on the regional dynamics of deep and interacting water-bearing strata have been formed.

The effect of man’s economic activity on subterranean waters has created the need for the study of complex computation systems; therefore, in addition to analytical calculation methods, methods of mathematical simulation using analog devices and digital computers have been widely used. This has made possible the performance of hydrogeological calculations with the fullest possible consideration of the natural situation and all the active factors. Continuous electric models made from electric conducting paper are usually used in solving steady-state problems, and hydrointegrators and grid electrical integrators with effective resistors (the Liebmann grid) or with effective resistors and capacitors (R—C grid) are used in solving nonsteady-state problems.

In addition to solving direct hydrogeodynamic problems, which provide a forecast of the conditions and balance of subterranean waters, the dynamics of subterranean waters also examines the solutions to the reverse problems—that is, the recreation of the parameters of a filtration system using data on subterranean water conditions (for example, from long-term operation of large subterranean water intakes and in the area of reservoirs and quarries). A new trend, in which the physicochemical processes that occur during the interaction of subterranean waters and the neighboring rock are studied, has acquired great significance in the study of the pollution of subterranean waters and in establishing the hydrogeochemical methods for mineral prospecting.