不同传感器数据在若尔盖湿地植被变化监测应用中的适宜性分析

Analysis of the Suitability from Different Remote Sensing Data on the Monitoring of Vegetation Change in Ruoergai Marsh

基于2000年2月到2001年12月的GIMMS-NDVI、VGT-NDVI和MODIS-NDVI数据,分析了此3类NDVI对若尔盖湿地植被变化响应方式的差异性及在该区植被变化监测研究中的适宜性,研究结果表明,3种遥感数据间不存在显著差异,传感器光谱特征是造成数据间差异的主要原因;MODIS、Vegetation传感器具有红光波段对叶绿素吸收敏感,近红外波段剔除了强水汽吸收带、空间分辨率高等优势,加之MODIS-NDVI和VGT-NDVI合成法包含有全面而有效的大气纠正处理,使得MODIS-NDVI和VGT-NDVI对若尔盖植被较GIMMS-NDVI敏感,较适宜于该区植被变化监测研究。但由于3类NDVI数据并无显著差异,且GIMMS-NDVI具有时间序列长这一MODIS-NDVI和VGT-NDVI无法比拟的优点,因此其在该区植被的长期连续监测中仍具有不可替代的作用。

Based on the NDVI data of different resources from Feb. 2000 to Dec. 2001,the difference and suitability of GIMMS-NDVI,VGT-NDVI and MODIS-NDVI responsing to the vegetation change in Ruoergai marsh were analyzed. The results showed that there was no significant difference among the three NDVI data,and the difference was mainly caused by the spectral characteristics of the sensors. The prominent sensitivity of red spectrum, removing water vapor absorption band in infrared spectrum and higher spatial resolution of the MODIS-NDVI and VGT-NDVI data,which resulted the two types data are more sensitive to the vegetation change and more suitable to the study of vegetation change than the GIMMS-NDVI in Ruoergai marsh. However,the GIMMS-NDVI has longer time series than the other two data,and will still play an important role on the study of vegetation change.