Thermohydrodynamic modeling of the influence of deep faults and degassing channels on groundwater dynamics

Authors

  • V.M. Shestopalov Institute of Geological Sciences of the National Academy of Sciences of Ukraine, Scientific and engineering center of radiohydrogeoecological polygon studies of the National Academy of Sciences of Ukraine, Ukraine
  • A.S. Bohuslavsky Scientific and engineering center of radiohydrogeoecological polygon studies of the National Academy of Sciences of Ukraine, Ukraine

DOI:

https://doi.org/10.24028/gzh.0203-3100.v42i2.2020.201738

Keywords:

geological environment, permeability, filtration, migration, modeling, fluids, degassing, dilatency zone

Abstract

The authors developed a thermohydrodynamical 2D model of a vertical section of the geological environment of groundwater, taking into account deep active geodynamic zones. Such zones (fast filtration and migration zones — FFMZ) are actually permeable faults and their associated surface depressions and under-depression degassing channels. Their depth may be different, but they are also very deep (more than 7 km). Under these conditions, the formulation of a purely hydrodynamic problem is insufficient. It is necessary to take into account the heat flux coming from the interior and affecting the hydrodynamic features of the filtration. The HYDROTHERM program used by the authors, developed by the US Geological Survey, allows us to solve such problems. The hydrogeological schematization of the model section is selected in accordance with its intended location within the left bank of the Kyiv region, the Dnieper―Trubizh interfluve. To build the model, the authors used the available data on the location, distribution density over the territory, and the characteristics of the FFMZ activity. The vertical distributions of temperature and fluid flow rates are obtained, and the deep influence of the FFMZ on their formation is clarified. The presence of a dilatency zone, which is characterized by branching of fractures in the geological environment, is confirmed at a depth of 3―7 km at specified parameters of the model. In this zone, with a decrease in depth, an intermittent process of discharge of a stress-strain state of rocks, a decrease in the pressure of the ascending fluids, and their gradual degassing occur. The activation of fluid flows at these depths without preliminary specifying increased permeability in the model indicates the participation of fluids in the formation of the dilatancy zone.

References

Vitovtova, V.M., Shmonov, V.M., & Zharikov, A.V. (2011). Distribution of the pore sizes in the continental crust: inferences from experimental data about permeability. Vestnik Otdelenia nauk o Zemle RAN, 3, NZ6018. doi: 10.2205/2011NZ000148 (in Russian).

Kutas, R.I. (1978). Heat flux field and thermal model of the Earth's crust. Kiev: Naukova Dumka, 147 p. (in Russian).

Shestopalov, V.M. (2014). Hydrodynamic zones and water exchange in the hydrogeological structures. Geologicheskiy zhurnal, (4), 9―26 (in Russian).

Shestopalov, V.M., Lukin, A.E., Zgonnik, V.O., Мakarenko, А.N., Larin, N.V., & Bohuslavsky, А.S. (2018). Essays on Earth degassing. Kiev: Publ. Radioenvironmental Centre, Institute of Geological Sciences, NAS of Ukraine, 632 p. (in Russian).

Hayba, D.O., & Ingebritsen, S.E. (1994). The computer model HYDROTHERM, a three-dimensional finite-difference model to simulate ground-water flow and heat transport in the temperature range of 0 to 1200 °C. U.S. Geological Survey, Water-Resources Investigations Report 94-4045. Reston, Virginia. 85 p.

Kipp, K.L., Hsieh, P.A., & Charlton, S.R. (2008). Guide to the Revised Ground-Water Flow and Heat Transport Simulator: HYDROTHERM, Version 3. Techniques and Methods. 6-A25. U.S. Department of the Interior, U.S. Geological Survey. Reston, Virginia. 178 p.

Rojstaczer, S.A., Ingebritzen, S.E., & Hayba, D.O. (2008). Permeability of continental crust influenced by internal and external forcing. Geofluids, (8), 128―139. doi: 10.1111/j.1468-8123.2008.00211.x.

Published

2020-05-18

How to Cite

Shestopalov, V., & Bohuslavsky, A. (2020). Thermohydrodynamic modeling of the influence of deep faults and degassing channels on groundwater dynamics. Geofizicheskiy Zhurnal, 42(2), 3–13. https://doi.org/10.24028/gzh.0203-3100.v42i2.2020.201738

Issue

Section

Articles