Snow Cover Monitoring And Snow Cover Production System Based On Remote Sensing Images

Snow is an important component of cryosphere, and it influences the earth radiation balance and water circulation by its strong reflection and weak absorption features. Snow is sensitive to climate change, having a close relationship with the global climate change; snowmelt water is a kind of important water resources and recharges many rivers; frequent snowfall will probably lead to natural disasters and damage people’s life and property tremendously. Therefore, monitoring snow cover change accurately is very important for understanding global climate change, assessment of water resources change and disaster prevention. And the snow cover area is one of the most important parameters of snow.Remote sensing technology has macroscopic monitoring capability with a large coverage, timeliness, and a high degree of accuracy. It is an important technique in the study of global change, which can monitor snow change and evaluate ecology dynamically for the local area or the global. The paper takes Mountain Tianshan as the study area, and the research includes three aspects: snow cover area extraction, snow cover change prediction, snow cover production system. The research contents and the conclusions as follows:(1) Study the applicability of several typical extraction methods, and, based on SNOMAP algorithm for snow mapping, the research use domestic satellite HJ-1B IRS data to extract snow cover area with HJ-MNDSI method. We compared it with TM data and determined the threshold value, then produce snow cover map of Tianshan from 2008 to 2014. Meanwhile, we computed the snow pixels rations of every year. Tests show that HJ-MNDSI algorithm can extract snow cover area very well.(2) Using MODIS snow products(MOD10) in Xinjiang region, the study explores the suitable model method to snow change prediction. This paper discusses grey system analysis model, Fourier analysis, and time series analysis model for prediction of snow change. The results show that grey prediction is better, various validation indexes are reasonable.(3) For the former two parts of research, this research designs snow cover product process based on remote sensing images, realizing the snow cover production system(mainly includes remote sensing image reading, remote sensing image pretreatment, snow cover area extraction, and generating snow map products and so on). It improved the snow cover products production efficiency based on remote sensing images.