基于3S技术的牧区雪灾评价方法

Evaluation approach to snow disasters in pastoral areas based on 3S technologies

利用NOAA卫星数据及地面气象台站观测资料,建立了积雪深度遥感反演模型;应用线性混合光谱分解原理,研究了基于像元的积雪覆盖率及积雪空间分类算法;依据草地畜牧业的特点,综合考虑了雪情、草情、畜情和气象因素的空间分布及其对草地畜牧业的危害程度,提出了2种新的基于格网单元的积雪危害指数和雪灾综合评价指数,构建了积雪危害分级与雪灾综合评价标准。通过对北疆阿勒泰牧区雪灾研究的结果表明,这2种指数和分级评价标准能准确详细地反映雪灾的时空分布特征和危害程度,对牧区雪灾的综合评价具有重要的应用价值。

NOAA satellite digital images and observed climatic data were used with a monitoring model to simulate snow depth. The pixel-based snow coverage rate and snow spatial classification were studied using a linear mixture spectrum disassembling method. Based on the spatial distribution characteristics of snow, grassland, animal and climate factors and their hazards, two new quantified indices, based on grid data layers and used for estimating snow hazard grade and integrated evaluation of snow disasters of grassland and animal husbandry, are proposed and the standards for grading snow hazard and snow disaster evaluation have been developed. Results showed that these two indices and standards can accurately reflect the details of snow hazard grade and snow disaster magnitude in both temporal and spatial scales. They will have an important role in integrated evaluation of snow disasters in pastoral areas.