2008-2009年中国北方干旱遥感动态监测

Dynamic drought-remote sensing monitoring in north China from 2008 to 2009

干旱是威胁我国及世界农业发展的自然灾害之一,利用遥感技术进行干旱监测与评估已成为一种重要而有效的手段。2008年10月至2009年2月,我国北方地区出现了大面积的持续干旱,给冬小麦的生长造成了严重的影响。基于2000年至2009年Terra卫星MODIS传感器8天合成的地表反射率数据,结合地面实测土壤水分和实地调研数据,利用距平植被指数(AVI)和距平水分指数(AWI)对我国北方冬小麦主产区的干旱程度进行了分级,对干旱的发生、发展和时空变化情况进行了连续监测,得到了该时期的旱情分布结果:2008年10月份以后旱情逐渐加重,2009年1月下旬各地旱情达到了最严重的程度。研究表明,AWI对干旱的反应比AVI敏感而且准确。

Drought is one of natural disasters that threaten agricultural development in China as well as around the world. Remote sensing has become an important and effective technology for the monitoring of soil moisture and drought. The everlasting drought that occurred extensively in north China from October 2008 to February 2009 had impacted seriously on the growth of winter wheat. This paper classifies the drought into five levels by anomaly vege- tation index （AVI） and anomaly water index （AWI） based on 8 day composite MODIS （ Moderate Resolution Ima- ging Spectroradiometer） surface reflectivity data and land water content measurements, and then monitors the oc- currence and development of drought continuously. Results indicate that the drought has become more severe since October 2008, and in late January 2009, drought is the most serious. The study also shows that AWI is more sensi- tive and accurate to reflect the degree of drought than AVI.