基于MODIS与AMSR-E数据的中国6大牧区草原积雪遥感监测研究

内蒙古、新疆、西藏、青海、甘肃和四川的草原区这6大牧区是中国重要的畜牧业生产基地,也是雪灾频发的区域,及时、准确地获取6大牧区雪情时空特征对于防灾减灾,指导畜牧业生产有着重要的现实意义。光学遥感与微波遥感各具优缺点,综合运用MODIS和AMSR-E数据构建草原积雪遥感监测模型,以日为监测单元,以旬为多日合成时段,对中国6大牧区在2008年10月上旬至2009年3月下旬间的草原积雪覆盖范围进行监测,并对监测结果进行检验,以此说明MODIS与AMSR-E数据在雪灾监测方面协同监测的可行性,为其他雪盖遥感监测研究提供参考。

Snow Monitoring Using MODIS and AMSR-E in Six Main Pastoral Areas of China

The six main pastoral areas (Xinjiang, Tibet, Qinghai, Sichuan, Gansu, and Inner Mongolia) are the important production base of animal husbandry in China, and also the frequent snow disaster areas. To obtain snow conditions of these pastoral areas timely and accurately is valuable for disaster prevention and reduction. With higher spatial resolution and stronger interpretation, optical remote sensing is better for snow cover identification, but it is vulnerable to cloudy weather. Microwave remote sensing is not easy affected by cloud, but identification accuracy is not high. In this paper, we integrated the two kinds of data to identify snow covers. The MODIS data (optical) are used in cloud-free areas, while AMSR-E data (microwave) are used in the rest areas. According to the method, each single day is defined as monitoring unit, and every ten days compose the image combining unit. The monitoring area covers the six main pastoral areas of China. The monitoring duration is from October 1^st, 2008 to March 31^st, 2009. The main conclusions are as follows: 1) The grasslands Northern Xinjiang, eastern Tibet, south-west of Qinghai, central Gansu, northern Sichuan, the Xilin Gol, and Hulunbeier of Inner Mongolia are the areas with frequent snow cover. 2) The monitoring area possesses the smallest snow cover in December 10^th to 20^th, while it has the biggest snow cover in January 1^st to 10^th. 3) During the monitoring period, the fluctuation of snow-cover area can be concluded in three types: Xinjiang and Inner Mongolia have the single peaks, Tibet and Qinghai have three peaks and three valleys, and Sichuan and Gansu are relatively stable.