The Study For The Structuring Of Snowmelt Model On Condition That Seasonally Frozen Ground Presence

With global warming, the issue of water resources increasingly causes ourconcern. As one of the important water resources, snow which of course will be adisaster in the form of snowmelt flood under certain circumstances has anincreasingly close impact on people. Based on this, how to use the snowmeltresources better and to avoid snowmelt flood disasters is an urgent problem for aridarea where snow is the main supply of water. It has great significance for better use ofthe snowmelt resources and reducing the snowmelt flood disasters to study theformation process of snowmelt flood in detail and to reveal the formation mechanismof snowmelt flood. At the same time, hydrological model is a main way to study thewater management of river basin and runoff formation and migration. So it isparticularly necessary to study snowmelt runoff mechanisms on seasonally frozenground as well as its model study in Xinjiang where seasonally frozen ground andsnow cover are widely distributed.Based on the existing research of our term, we divide the snowmelt runoffgeneration process into the processes of snowmelt, water-holding of snow cover,snowmelt water refrozen in snow cover and infiltration on the seasonally frozenground. After that, combining with the theory of energy balance and mass balance webuild a snowmelt runoff model based on the grid scale with the idea of modularization,drive the model using meteorological data measured really in the typical study areaand simulate the change process of snow water equivalent and the outflow process ofsnowmelt water in the test site of study area from March14thto March18thin2009,achieving a good result that the deterministic coefficient is0.78and the relative errorof the maximum peak is8.6%in the entire simulation period. Then combining theWRF regional climate model and MODIS imagery data and DEM data with thesnowmelt model and isochrones convergence method, we build a distributedsnowmelt runoff model in spatial scales and simulate the change process of snowwater equivalent of spatial scales and the runoff process of the outlet section ofJuntang River from March10thto March31stin2011, achieving the result that thedeterministic coefficient is0.86and the relative error of the maximum peak is0.65%in entire simulation period. The data show that we get a good result. The result of thisstudy has a reference value for the study of the formation process of snowmelt floodand runoff simulation of river basin especially in arid area, and the rational use ofsnowmelt water resources.