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针对春季农作物风沙灾害监测快速、准确的要求,提出了农作物风沙灾害的遥感监测方法。以2009年4月阿克苏市风沙灾害为例,基于MODIS每日地表反射率产品,对阿克苏市农作物风沙灾害前后和恢复期的NDVI进行了动态监测,并利用同时期正常年份的NDVI变化确定农作物受灾阈值,通过统计分析确定受灾农作物的面积。结果显示:阿克苏市农作物风沙灾害前后和恢复期,农作物NDVI最大值从0.36增大到0.73,占农作物总面积比例最大的NDVI值从0.08增大到0.11;阿克苏市受灾农作物面积12697.07hm2,负向-正向型农作物受灾面积占总受灾面积的35.16%,正向-负向型农作物受灾面积占总受灾面积的63.06%,负向-负向型农作物受灾面积占总受灾面积的1.78%。该方法对农作物受灾面积的提取精度为98.24%,是一种方便、高效和实用的农作物风沙灾害监测方法。
Aiming at the requirement of rapid and accurate monitoring of wind-blown disastrous crops in spring, a remote sensing monitoring method of crop wind-blown disasters was put forward. Taking the sandstorm disaster of Aksu City in April 2009 as an example, the NDVI of the crops before and after the sandstorm disaster in the Aksu City was monitored dynamically based on MODIS daily surface reflectance products. The NDVI of the normal years in the same period was used to determine the crop damage Threshold, by statistical analysis to determine the affected area of crops. The results showed that the maximum value of crop NDVI increased from 0.36 to 0.73 before and after the sandstorm disaster in Aksu City, and the NDVI value which accounted for the largest proportion of the total crop area increased from 0.08 to 0.11. The affected area of Aksu affected 12,647.07hm2, - The area affected by the forward-type crops accounted for 35.16% of the total area affected, the area affected by the positive-negative crops accounted for 63.06% of the total area affected, and the area affected by negative-negative crops accounted for 1.78% of the total area affected. The accuracy of this method is 98.24% of the area harvested by crops, which is a convenient, efficient and practical method for monitoring sandstorms in crops.