中国北方草原区积雪遥感监测--2007．10～2008．3期间

Remote sensing monitoring of grassland snow in China:From October 2007 to March 2008

着眼于我国草原防灾减灾以及国家开展重特大雪灾应急响应工作的极迫切现实需求,基于NASA MODIS数据,以天为监测(响应)时间单元,以旬为监测集成时段,对2008年春节大雪灾期间我国草原积雪状况实现了系统的遥感监测,获取了2007年10月至2008年3月期间中国北方9省区草原积雪发生范围及其面积等数据信息,揭示了监测期间我国草原积雪发生的时空特征。青藏高原与内蒙古为我国持续降雪的核心区域,其他地区降雪情况随时间出现一定的波动;除东北地区外,积雪面积均在1月下旬达到最大值;各省区草原积雪面积占草原总面积的比例随时间的变化总体持续增加。

Snow disaster is one of the main meteorological disasters in the grassland pastu- ring area of China in winter and spring. Based on the NASA MODIS data, remote sensing was used to monitor the grassland snow disaster in early 2008. The data of grassland snow was successfully obtained covering from October 15th, 2007 to March 20th, 2008 of nine provinces, including Inner Mongolia, Liaoning, Jilin, Heilongjiang, Sichuan, Tibet, Gansu, Qinghai and Xinjiang. It can provide complete, timely and exact science reference for the agricul- ture department to make decisions about disaster prevention and reduction. The results show： （1） For the absolute comparison of the grassland area in the nine provinces, during the whole monitoring period, the average snow area of grassland in Xinjiang is the largest, which is 291485 km2. The least is Liaoning, which is 2483 km2. In the period, the order of snow area of all the provinces is Xinjiang, Inner Mongolia, Tibet, Qinghai, Sichuan, Gansu, Heilongjiang, Jilin and Liaoning. （2） As the proportion of snow area of every province to its own total grassland area, in each phase of the period, Xinjiang has the largest proportion to the whole province＇s to- tal grassland area, which is 38.15%. Liaoning＇s grassland snow area is the least, which is 3.04%. In each monitoring phase, every province grassland snow area to the total grass- land area is ordered by Xinjiang, Qinghai, Sichuan, Gansu, Inner Mongolia, Hei- longjiang, Tibet, Jilin and Liaoning. （3） During the monitoring time period, Qinghai-Tibet Plateau and Inner Mongolia are the core snowing areas, and there are fluctuations of snowing in the other areas. （4） Monitoring started from October 15th, 2007, when fluctuations of grassland snow area existed, the total snow area increased. In the late January of 2008, the gi＇ass- land snow area reached the maximum value, and then it tended to decrease. The total grassland snow area in the monitoring area reached the maximum value in the late January of 2008, which is 2251141 km2. （5） At the beginning of the monitoring period, 10% of the grassland was covered by snow on average in every province. In the late January of 2008, the proportion of grass- land snow area to the total grassland became 61.48% on average. At the end of monito- ring period, which is mid-March, about a quarter of grassland was covered by snow in.ev- ery province of the nine.