Author(s): Cinzia Mazzetti; Ezio Todini
Linked Author(s):
Keywords: Snowmelt; Distributed hydrological model; Snow water equivalent
Abstract: Snowmelt is a significant surface water input to many aspects of hydrology including flood control. The physical processes within a snow pack and involved in snowmelt are highly complex, involving mass and energy balances as well as heat and mass transport by conduction, vapor diffusion and melt water drainage. A complete physical description of all processes requires high level of sophistication in modelling and detailed environmental data. In hydrological applications such as flood forecasting the availability of data is often reduced to the sole precipitation and air temperature measurements, which makes most of snow models unusable. The paper presents a single parameter snow melting model that is part of the distributed physical based hydrological TOPKAPI model. Snowmelt is based on energy balance and the model requires only one parameter, representing the value of air temperature at which snow starts melting. Air temperature and precipitation measurements are the only data required to run hydrological and water resources management simulations. A test on the efficiency of the model was conducted using data from Reynolds Creek Experimental Watershed, located in the Owyhee Mountains in south-western Idaho, USA. The RCEW database contains hourly data for precipitation, air temperature and snow water equivalent (SWE). A 14 years long simulation (1983-1996) was run continuously on Reynolds Creek; SWE was simulated at snow courses locations and compared to the values contained in the database. The results show that snow formation is very well reproduced by the model. Snow melting is less precise due to a delay in snowmelt starting. In any case melting rate is correctly simulated and delays are about a few days.
Year: 2007