ESTIMATION OF GLACIAL DEBRIS FLOW CHARACTERISTICS USING A CHAIN OF MATHEMATICAL MODELS

Abstract

The paper discusses the application of a chain of mathematical models for calculating glacial debris flow. Modeling was carried out for the Bodomdara River valley for the case of an outburst of Lower Bodomdara Lake (Gorno-Badakhshan Autonomous Region, Tajikistan). FLOVI program, written in the Python programming language, was applied; it combines equations for calculating the lake outburst hydrograph and the characteristics of debris flow during its formation. To calculate the outburst flood hydrograph, the model of lake outburst through an intraglacial channel developed by Yu.B. Vinogradov was used. Additional calculations were made with a change in the length of the intraglacial channel. With a decrease by 100 m, the maximum discharge can increase by 7% The flow characteristics in a potential mudflow source were assessed using a transport-shift model of debris flow formation. Since there were no initial data on the parameters of the debris flow source, the author conducted numerical experiments. The flow in the valley was simulated using the FLO-2D hydrodynamic model. Calculations were performed for two scenarios: 1 – the entire complex of mathematical models, 2 – without the transport-shift model. According to the simulation results for scenario 2, the area of the potential flood zone was found to be less by almost 19%. Thus, the use of the entire chain of models makes it possible to obtain more realistic flood zones.