|
|
Analysis of main controls of runoff events in the Sumava Mts. caused by rain-on-snow
Šťovíček, Vít ; Jeníček, Michal (advisor) ; Juras, Roman (referee)
Rain-on-snow (ROS) events are hydrometeorological phenomena when a sufficient combination of rainfall and snowmelt can generate floods, snow avalanches or landslides. As average air temperature gradually increases, the trend of ROS events occurring earlier in spring and at higher altitudes can be expected to continue. Snowmelt during ROS events is controlled by the snowpack energy balance and is influenced by several factors, especially meteorological conditions, and initial conditions of the snowpack. The calculations were made using data from four automatic stations in the Šumava Mountains, namely the Vydra river basin. Based on these data and pre-defined threshold conditions, 105 ROS events were selected. Resulting components of the energy balance, climatic, snow and outflow characteristics were mutually correlated, and their influence on ROS events was determined. The analyses showed that during ROS events, the most important source of energy for melting were turbulent fluxes, i.e., latent, and especially sensible heats. According to the monthly averages, they accounted, at almost all observed stations, for at least 40% (and up to 60% in December), of the total energy available for snow melting. Another important energy flux was shortwave radiation, whose fraction increased with the progress of...
|
guest ::
