Abstract

Using long-term field-exploration studies and aerial and space photography, the erosion coefficient values of mountain slopes in the water catchment basins of Georgias principal mudflow type rivers are estimated, with account of the eroded area and time factor.

To establish the link between the erosion coefficient and the degree of mountain slope damage use has been made of the scale of Ts. Mirtskhoulava and R. Morgan, according to which the slope erosion class and the erosion intensity have been determined, with account of the time factor.

In order to predict channel processes in mudflow type rivers, a dependence has been obtained on the basis of an analysis of the field-expeditionary studies carried out in nature (1981-2005). This dependence permits calculation of the maximum discharges of various provisions of turbulent mudflows, with account of the diagnostic variable.

Using the theories of probability and of risk, the types of the law of distribution describing the eroded and accumulated sectors have been determined: the reliability of the stability of the longitudinal river profile and corresponding risk are studied for cases of separate happenings and synchronous impacts. The results obtained allow precise prediction of channel deformations in mudflow-type rivers and effective implementation of engineering ecological measures at the subsequent stage.

 

Keywords: debris flow, discharge, erosion coefficient, catchments area, river-beds, longitudinal profile, theory of reliability and risk.