论文部分内容阅读
为了分析2010年澳大利亚新南威尔士州大范围蝗灾的发生范围和受灾程度,利用2008—2010年MODIS/Terra数据,通过植被生长期内前后同期的NDVI差值图像△NDVI判断2010年植被长势情况。研究结果表明:从整体上看,监测到的受灾范围与受灾程度上基本一致,能较好的反映出新南威尔士州的受灾情况;2010年9月新南威尔士州未受灾面积约为41万km2;受灾较轻区域面积约为5万km2;受灾较重区域的面积约为34万km2;受灾总面积约为39万km2,约占总面积的49%。通过与官方统计数据对比,监测到的受灾面积与官方统计数据相对误差为22%,造成误差的主要原因是像元的缺失与个别错误的像元点,导致受灾区域缺失的像元不能统计在受灾面积中和降低了受灾情况分类的精度。可得出结论,此方法适用于在对蝗灾发生范围和受灾程度的研究中。
In order to analyze the extent and severity of the large-scale locust plague in New South Wales, Australia in 2010, MODIS / Terra data of 2008-2010 were used to judge the vegetation growth in 2010 through NDVIVI of NDVI during the vegetation growth period. The results show that: Overall, the extent of the damage monitored is basically the same as that of the affected area, which can better reflect the disaster situation of New South Wales. In September 2010, the unassailable area of NSW was about 410,000 km2; the less affected area is about 50,000 km2; the hardest hit area is about 340,000 km2; and the total affected area is about 390,000 km2, accounting for about 49% of the total area. By comparing with the official statistics, the relative error between the monitored area and the official statistics is 22%. The main reason for the error is the lack of pixels and the pixel points of individual errors, resulting in the missing pixels in the affected area can not be counted Neutralization of affected areas reduces the accuracy of the classification of the affected conditions. It can be concluded that this method is suitable for use in the study of the extent and extent of plague occurrence.