The Study On Snow Melt Processes Simulation And Frozen Effects Analysis

Snow resource is very abundant in Xin Jiang province. Seasonnal snowmeltrunoff is the main water resource for Xin Jiang rivers. Thus, the rational use of waterresources plays an important role in all regions of Xinjiang. As a significant freshwater resource, snowmelt water also could cause large damage in the form offlood,have effects on people’s daily lives even threat to people’s lives and propertysafty. Water and thermal characteristics of the permafrost could change the energy ofsoil and atmosphere and water conditions.The simulation of freezing and thawingprocess is an important part in land surface model for current stage. Seasonal frozensoil and snow cover are widely distributed in Xinjiang.It is essential to carry out thestudy of snowmelt process in the presence of seasonal frozen soil conditions.Based on the continuous field observation data,The VIC model is driven tosimulate the snowmelt process and hydrothermal effects of frozen soil.Theconclusions are drawed as follows:(1) measured data and simulation data were verified. During the snowmelt periodin2009and2010,the NASH efficiency coefficient of net radiation is0.83and0.85respectively,the average soil temperature all achieved0.8, the simulation of soilmoisture is not good, in general, the top simulation results are better than the lower.(2)The snowmelt process were simulated during the2009and2010snowmeltperiod. The NASH efficiency coefficient of snow water equivalent is0.92and0.9.Analyzed the energy composition of the snow surface in the snowmelt period of2009and2010, it is conclude that the net radiation is the main integral part of energy, theeffects of turbulent exchange (sensible heat and latent heat fluxes) were fllowed,theeffect of the ground flux is very limited.(3) By comparing the different simulation result with/without frozen soilalgorithm, the great influences on the water cycle of frozen soil were proved. The soiltemperature of with frozen soil algorithm is higher than the without. This is due to the soil freezing process can effectively prevent the temperature of the surface pass todeep soil layers. Permafrost has an important impact on hydrological processes in coldregions,it is conclude that frozen soil as an impermeable stratum can decrease theinfiltration rate and evaporation.