Using SPOT-VEG based vegetation indices compared with AVHRR-based vegetation indices for drought monitoring in the south of Iran

摘要

To evaluate the capability of SPOT-Vegetation data for hydrological drought monitoring in the Middle East, a study plan was designed involving the production of a normalized difference vegetation index (NDVI) and a vegetation condition index (VCI) and correlating their values to groundwater level data. SPOT-VEG vegetation maps were collected from 1998 to 2007. For validation, raw AVHRR images from 1998 to 2007 were collected. Geometric and radiometric corrections were performed and groundwater level statistics were collected. Standard water level index (SWI) was applied. The Pearson correlation was used to correlate NDVI and VCI values to SWI data. Good correlations were obtained between average NDVI and average three month SWI. The results indicated that SPOT-Vegetation derived NDVI and VCI reflect the SWI fluctuations in the study area well because of unlimited groundwater consumption for irrigation.