利用SPOT数据进行干旱监测的应用研究

Applied Research on Drought Monitoring Using SPOT Data

植被状态与环境干湿程度密切相关,而归一化植被指数(NDVI)是植被状态的最直接表现。利用NOAA/AVHRR对植被生长环境的干旱监测研究已较成熟,并积累了一些如距平植被指数等快速、便捷的干旱监测方法。利用比利时佛莱芒技术研究所提供的1998—2006年SPOTVGT数据,采用距平植被指数干旱监测方法,对宁夏回族自治区2000年春末夏初遭遇的特大干旱进行监测,并用1998—2005年平均分布于全区的各气象监测点观测数据进行验证。结果表明,利用SPOTVGT数据能够较准确地监测出干旱发生的范围和相应的干旱程度,基于SPOTVGT数据的距平植被指数干旱监测模型可以作为一种快速、便捷的干旱监测方法,在实践部门进行推广应用。

Vegetation condition has a close relation with the dry and wet degree of environment. The normalized difference vegetation index（NDVI） is a good index indicating the condition. Generally, the NOAA/ AVHRR data may be used to monitor drought and there are some successful methods such as anomaly vegetation index（AVI） for the purpose. At present, the Flemish Institute for Technological Research, Belgium （VITO）, freely provides a set of SPOT VGT NDVI data from 1998 to 2006. Using the AVI calculated from the SPOT VGT NDVI data from 1998 to 2006, drought grade in the monitoring year was classified. The study successfully monitored the drought that occurred in Ningxia Hui Autonomous Region, Northwest China, in 2000. The result was also validated using meteorological observation data collected from some weather stations in Ningxia. It is shown that the method can be used not only to accurately monitor drought range and degree but also to help the governmental departments in related areas.