The Research Of Snow Runoff Mechanism During Snowmelt Period On The Northern Slope Of Tianshan Mountaios

Snow has the beneficial side as well as the disadvantageous side, because of thespecial characteristic of snow, and it is more disadvantageous for Xin Jiang Province,China. From the recent statistical data, the casualties and economic losses caused byspring flood due to the seasonal snow melting are not in the minority in Xin JiangProvince in Spring. Therefore, it is necessary for snowmelt period to make the snowrunoff mechanism clear, and it has important reference meaning for the calculatingof snow runoff and the forecasting of spring flood.We have gotten a number of primary data by continuing observation in theresearch area in snowmelt period. After that, I will use the statistical and analysissoftware, such as SPSS19.0, surfer8, DPS7.05, Arcgis10.0, Excel and ENVI4.7et al,to statistic and analysis the data we have collected from2010to2013in thesnowmelt period. Then the figure and diagram can be acquired based on the result ofanalyses. The snow runoff mechanism will be explained and anglicized in two aspect,the energy balance and the snow melt water. The result shows that:(1) The key factor of snow melting is the import of energy, while whether thefrozen soil exit or not will influence the efficiency and amount of snow runoff yield,meanwhile, that will also change the direction of snow melt.(2) The snow moisture content is important indicator for snow melting and thetransporting of melting water, as well as the transporting of energy in snow layer. Inthe simulation of snow moisture content by spectral reflectance, the sensitive band ofsnow moisture content lies in near-infrared, especially in1400nm. The equation,which is based on the spectral reflectance of1400nm, has high fitting degree, and theaccuracy can reach82%.(3) In snowmelt period, the change tendency of the particle size of snow hasbeen enlarged; it affects water-holding capacity of snow layers together with snow depth, thus affects the runoff of snow. Snow particle size and the snow out of theflow time was significantly negative correlation, the correlation coefficient is0.887,and the snow depth and snow up to0.98, the correlation coefficient of the flow oftime through a significant level of0.001significance test;(4) Temperature is a performance of solar radiation intensity degree, and willpromote the snow melting. Air temperature and snow temperature are both close tothe moisture content of snow, and the temperature of snow and snow moisturecontent is also very close, the correlation degree between each other can get throughthe significance test of0.01significant level.(5) In snowmelt period, the progress of snow evaporation is complex,temperature and wind speed can influence the intensity of evaporation, but thesubtraction of relative humidity determine the direction of the evaporation andcondensation dynamic equilibrium.(6) In the simulation process of snow runoff mechanism, both regressionanalysis and BP neural network simulation have higher simulation degree, and theerror is relatively small, especially the2-2-1neural network model, the deviation oftime error can be just10minutes, and the deterministic coefficient at about0.99.