迭部“4.15”森林大火的气象条件及EOS遥感监测

Meteorological Condition and EOS Telemetry of “4.15” Diebu Forest Fire

利用2003年4月15～18日甘南迭部重大森林火灾资料以及2002年5月-2003年4月气象资料，分析了火灾的天气气候成因，同时利用相应的EOS／MODIS遥感资料分析了前期土壤湿度以及着火状况。结果表明：冬、春季气温偏高、降水偏少，持续数月干旱是甘肃南部发生重大火灾的主要气候背景。西北区东部过渡季节干旱少雨的500hPa平均环流特征是欧亚大陆东岸大槽偏深、新疆脊偏强。北方冷空气底部锋区南压，青藏高原上偏南气流发展是甘肃南部火灾环流形势之一。气温持续上升、湿度持续下降是火灾发生、蔓延的重要条件。通过研究发现，EOS／MODIS资料能够较好地反映火灾前期的土壤湿度状况，是准确监测火灾发生、估算火区面积、强度和蔓延趋势最有效途径。

Based on the fatal forest fire data from 15 to 18 April 9.003 in Diehu, meteorological data and EOS/MODIS data from May 2002 to April 2003, the Meteorological Conditions of the fire are analyzed. The result shows that higher air temperature and fewer precipitation in winter and spring, and long-term drought are the primary climate background of the fatal forest fire in the south of Gansu. The characteristics of 500hPa mean circulation of drought are as follow. There is a strong ridge at Xinjiang and a deep trough at the eastern coast of Eurasia. Cold front moved to south of Gansu and southerly wind developing is one of circulation features of fire in al decrease of humidit the soil humidity can tect the happening of the south of Gansu. Continual increase of air temperature and continuy are the important conditions to fire happen and extend. It shows that be reflected by EOS/MODIS, which is the most effective means to dethe fire, estimate the fire area of the fire.