Snow Depth Changes On The Response Of The Impact Factor Analysis And Simulation Study In Western Tianshan

Snow depth is estimated snow water equivalent, river basin water balance and spring snow melt runoff simulation of some important parameters. At present in view of the snow depth research mostly focused on the existing models or based on remote sensing, the snow melted snow depth change influence factors in the process of study is less, can't provide effective parameter for snow depth model, lead to model complex snow depth.Snow melt period of snow depth is a complex nonlinear system, the change of snow depth affected by temperature,precipitation,net radiation, vapor pressure, the influence of such factors as if can use less influence factors reflect the change of snow depth, will reduce the input parameters when the snow is model, simplified model of the snow depth.Based on Gongnaisi river basin as the research object, this paper analyzes the basin annual snow depth change, and to study the correlation of snow depth and impact factor. Using projection pursuit method on snow depth change impact factor contribution to sort, get three main impact factor that result in the change of snow depth, will be three main factors influencing extracted as input parameters of the model, snow depth of snow melt period to simulate snow depth. Neural network is presented based on the factors of snow depth model, projection pursuit method to extract the main influence factor and the former rate component analysis to extract the main influence factor of the snow depth of neural network model is set up respectively, through the comparative analysis on simulation precision of the model. The main research results are as follows:(1) In Gongnaisi basins, Snow accumulation period from October each year, to deep snow peak in February of next year; Snow melt period starting in February each year, to the snow is melting in late April early may disappear.(2) The snow melt period of snow depth and the different between the impact factors, and the surface temperature of the most closely related degree, the correlation coefficient reaches 0.923.Snow depth influence factor between multiple collinearity, impact factors influence each other between change independent factor and the relevance of the snow depth.(3) In this paper, using the projection pursuit method to extract the three main factors that result in the change of snow depth. Namely atmospheric temperature, net radiation, precipitation will be three main factors as input parameters of the snow depth model can obtain reliable snow depth, high simulation precision, realize the main factors that influence the snow depth the purpose of simplified snow depth model.(4) By comparing the analysis model based on projection pursuit method of snow depth and snow depth model based on principal component analysis accuracy,found that by using projection pursuit method to extract the main factors that influence the snow depth is more reliable.