Pastral And Grassland Snow Hazard Monitoring And Risk Assessment Research In Inner Mongolia

This paper takes the snow disaster distributed in Inner Mongolia pastoral area as the research object. By using the RS, GIS, GPS and mathematical modeling technology, and combined with ground field investigation and analysis of social and economic statistical data, it finished a dynamics of temporal and spatial snow cover monitoring research. In this paper, a snow depth inversion model was established based on FY-3B microwave remote sensing data, and a rapid monitoring and evaluation snow disaster model compatible in Inner Mongolia pastoral areas has been developed. This research also developed a computer aided decision system that was about snow disaster monitoring and risk assessment. It is meaningful for government initialize snow disaster emergency management activities and corresponding decisions, it also contains siginificant contribution for the specific research and application. The major results are as follows:(1) The snow cover temporal and spatial dynamics monitoring in the past 10 years(2003- 2012) was investigated in the specific study. In time series period, the snow cover area changed significantly within an individual year, and the maximum snow cover area occurred in January and the smallest snow area occurred in October. In recent years, the total snow cover area of Inner Mongolia has a reducing trend and the annual average reduced rate was about 7km2. The first snow date was delayed and the snow end date became earlier and earlier. It indicated that the snow cover time period has reduced significantly. The annual average snow depth ranges from 2.29 cm to 3.9cm. The snow cover has a maximum depth in 2003 and has a minimum depth in 2008. The average snow depth also has a slightly decreasing trend and it’s reduce rate was about 0.56cm/10 a. In spatial distribution, the snow cover area changes in Xilinguoluo and Wulanchabu grassland were dominated the total snow cover area fluctuation in Inner Mongolia. In Inner Mongolia, the spatial covered more than 10 cm snow depth were mainly distributed in Greater Khingan Range mountain area and this area has an early beginning snow date and late date of ending snow cover. So this area has a longer snow cover days.(2) This paper developed a snow depth inversion model based on the FY-3B microwave remote sensing data and it was suitable for Inner Mongolia pastoral area application. For this model, the evaluated coefficient of determination R2 was 0.59, the root-mean-square error of precision experiment was 3.12 cm and the average relative error was 18%. The preliminary result that using the model to monitoring the snow depth changes properties from December, 2012 to January, 2013 in Inner Mongolia, it indicated that: the area covered with more than 20 cm depth snow was enlarged significantly and the space distribution extended to the whole Xilinguole grassland and east of Hulunbeier grassland area. The results were compared with the meteorological site data distributed in study area, the validation has shown a good consistency.(3) The rapid monitoring and evaluation technology of Inner Mongolia pastoral areas was established in this study, it can monitor and evaluate the snow disaster situation after 4 hours of snow fall. Through monitored the snow situation of Inner Mongolia pastoral areas from December, 2012 to January, 2013,the disaster area was 4.562×105 km2. Among this, the light disaster area was 1.643×105km2, the moderate disaster area was 1.849×105km2, the worse hit area was 1.041×105 km2 and worst hit area was 0.29×104 km2. In Inner Mongolia pastoral areas, the disaster area involved 44 banners and counties and the population under influencing was about 9.48 million. The animals influenced by the snow disaster was 37.42 million. The accuracy reached 95.24% by comparing with the disaster case count investigation by Inner Mongolia meteorological department, so the monitoring result and the actual disaster situation were in good agreement.(4) The areas with highest risk of snow disaster happened were mainly distributed in northeast of Dongwuzhumuqin banner, south of Xinbaerhuzuo banner, western of Chenbaerhu banner and western of Ewenke banner. These results were in good agreement with the temporal and spatial characteristics of actual snow disaster distribution in Inner Mongolia. The mainly snow disaster was light situation, both worse degree and the highest light disaster occurrence frequency was about 76%. The highest worse snow disaster occurrence frequency was about 79%. They were mainly occurred in Xinlinguoluo and Hulunbeier grassland area.(5) Based on the procedures of the entire research, the research take Visual C# language as the development platform and using Arc GIS software and considering the systematic theoretic, it developed an computer aided decision software system that was applied in support of snow disaster monitoring and risk assessment.