On the Issue of Generation of Hydrodynamic Waves in the Shovi Gorge (Georgia) due to a Collapse on Glacier Tbilisa

Abstract

The occurrence of a glacial mudflow in the Shovi gorge on August 3, 2023 was caused by a destructive process on the Tbilisa glacier. Based on the existing picture of the spread of the mudflow, it is possible to carry out an analysis regarding the rheological qualities of the water-saturated soil mass that forms its basis. It is also possible to approximately estimate the parameters of various types of hydrodynamic waves, the generation of which was probably possible during the propagation of the debris flow. It seems that such a problem can be satisfactorily solved only in the case of a correct assessment of the values of dimensionless criteria for the flow of debris flow, which are convenient quantitative characteristics that simplify the analysis of the qualitative consequences of applying the principle of hydrodynamic similarity. For example, in the case of approximating the bed of a debris flow with a rectangular channel, you can use the results of well-known analytical solutions obtained under simplifying assumptions that are valid for certain intervals of variation in the Reynolds and Froude similarity numbers. In particular, in the shallow water approximation, in the case of sufficiently large Reynolds numbers, when the fluid flow is highly turbulent, the Froude parameter allows one to fairly correctly simulate changes in the flow regime that occur as a result of the generation of hydrodynamic waves. The negative effects that often accompany the process of propagation of wave disturbances largely depend on the type of these waves. Therefore, in the case of a mudflow in the Shovi gorge, it seems quite realistic, for example, the generation of the so-called rolling hydrodynamic waves, which could well have been among the probable causes that determined the catastrophic scale of the tragic event.