Effect of the Voellmy Coefficients on Determining Run-out Distance: A Case Study at Uzungöl, Turkey
In this study, the traditional Voellmy model which has been widely applied since 1956 for all types of avalanches was used in defining the path length to compute the run-out distance of avalanches that occurred in UzungÖl. UzungÖl, a village which is located in a valley of North-Eastern Anatolia was chosen as a pilot project area since some fatal snow avalanches occurred in this area in the 1992 winter season. Due to limited data and field observations, dynamic and turbulence friction coefficients were taken as µ= 0.155 and ξ= 500 m/s2,respectively, for well defined slopes. Although it wasn’t possible to check most of the computed values which need to be measured during an avalanche, the run-out distance was found to be determined quite accurately. A number of the Voellmy coefficients were tested to compute the run-out distance, and the effect of those coefficients on the hydraulic parameters of the avalanche, such as discharge, velocity and depth, was investigated.
Key Words: Voellmy coefficients, Run-out distance, Avalanche dynamic, UzungÖl