It is of significance to establish an integrated evaluation system of snow disaster in northern pastoral areas.Based on the NOAA satellite digital images,field observation data,and maps of grassland type and seasonal pastureland,this paper selected the winter and spring pasturelands in Aletai region of Xinjiang as the main area of snow disaster-remote sensing monitoring.With affecting factors of economy and the characteristics of natural resource distribution comprehensively analyzed,and using 3S techniques and field survey information,a fundamental information processing model for integrated evaluation of snow disaster was built up,and snow disaster-spatial evaluation indices and damage level systems were constructed.Natural and social systems and 20 indices were selected in snow disaster evaluation indicator system.Four principal factors,i.e.,snow cover area,snow depth on grassland,persistence days of low temperature,and livestock death rate,were used as the grading indices of snow disaster damage level,and the models of snow disaster identification and loss estimatation were set up to quantitatively analyze snow disaster.The results indicated that the system could accurately reflect the details of snow hazard grade and the situation of a disaster in temporal and spatial scales,which would help to carry out the dynamic monitoring and scientific estimatation of big area’s snow disaster in pastoral region.
全 文 :