1998年吉林省西部洪水过程遥感动态监测与灾情评估

RS motional monitoring and damage evaluation of flood process in western Jilim Province in 1998

用ＮＯＡＡ卫星资料对１９９８年吉林省西部地区洪涝灾害进行了动态监测，并以农田损失为主对灾情进行了评估。采用ＡＶＨＲＲ通道１与通道２的比值图像突出水体信息，在直方图上人机交互划定水陆边界，用统计数学方法确定了混合像元中水体与非水体的阈值。利用灾区当年的作物种植数据作出农田受灾面积评估，用受灾前后的植被指数图，进行农田受灾程度划分。对像元面积的精确计算可以提高受灾面积的计算精度，区域像无数的统计分析可以减少区域内灾害面积比例分析的误差。

flood disaster in the western Jilin Province in 1998 had been monitored by NOAA/AVHRR, its damages, mainly in field losses evaluated. The author projected water information by ratio images and of AVHRR channel 1 to channel 2, and delimited water-land boundaries on histograms with the thresholds value of water and non-water in mixed pixels using statistical method. Then the damagedfields area evaluation had been made with application of planting data in 1998, and damage degrees differentiated by vegetation index maps before and after the disaster. The error for damaged area ratio can be improved through pixel accurate statistical analysis.