MODIS数据在河南省耕地雪盖监测中的应用

Applying MODIS data to monitor snow cover in cultivated land in Henan Province

【目的】探讨利用MODIS数据监测河南省耕地雪盖的可行性,为减灾抗灾提供技术支持。【方法】利用多天的MODIS数据,通过计算归一化差分积雪指数,结合第2、4波段的波谱信息及植被指数,将雪、云与其他地物分开,再结合MODIS的云掩膜数据去除云的影响,实现雪盖的提取。【结果】2008年1月16、29、31日耕地积雪覆盖面积分别占全省耕地面积的13.04%、68.43%和65.23%,主要集中分布在黄河以南粮食主产区,且呈由西向东逐渐推移发展趋势。【结论】在基础地理信息数据辅助下,利用MODIS数据进行大面积雪情监测是可行的,监测结果得到地面调查支持,可进行业务化运作。将遥感监测结果和基础地理信息数据相结合,进行各种专题图的制作,可为减灾抗灾提供技术支持。

[Objective]The feasibility of using MODIS data to monitor snow cover in cultivated land in Henan Province was studied to provide technical supports for disaster mitigation. [Method ]Normalized difference snow index （NDSI） was calculated based on MODIS data of several days, combining with the spectrum information of the second and the fourth wave band and vegetation index, snow cover and cloud were separated from other objects. Then the snow cover was extracted from cloud by use of MODIS cloud mask data. [Result]The area of snow-covered cultivated land on January 16, January 29, January 31, 2010, accounted for 13.04, 68.43 and 65.23% of the total cultivated area in Henan, respectively, which mostly distributed in main grain production area in the south of Yellow River, and showed trends in gradually extending from west to east. [Conclusion ]Assisted by Geographic Information System （GIS）, MODIS data could be used to monitor large area of snow disaster, which was verified by the results of field investigation. Moreover, technical support could be provided to disaster mitigation through rendering thematic maps based on the results of remote sensing monitor and GIS.