Spatial and Temporal Monitoring of Agricultural Drought Using MODIS Sensor Images and Remote Sensing Techniques (A Case Study: East Azerbaijan Province)

Drought is one of the recurring meteorological events that occurs in whole of the world and leads to water scarcity, economical hazards and devastating social consequences. Traditional methods of drought monitoring often depends on meteorological data especially on precipitation data. Due to the low spatial resolution and some missing values of ground based data, estimation of meteorological drought indices from these data is not reliable. Remote Sensing techniques with fine spatial and temporal resolutions are considered as useful tools for agricultural drought monitoring. In this study, spatial and temporal distribution of agricultural indices (DSI, VCI, TCI) were evaluated in the East Azerbaijan Province during the years of 1382 to 1393 (Iranian calendar), using the satellite images of MODIS. Also correlation between agricultural drought indices based on remote sensing data and meteorological drought index (SPI) was investigated. Results showed that the remote sensing indices had a good accuracy in the monitoring of agricultural drought, for instance the correlation coefficient between DSI and SPI indices was 0.64. Evaluation of SPI and agricultural drought indices indicated that moderate drought occurred in the most stations in 1387. However, the northern areas (Aras riverside) had a better vegetation condition in comparison to other regions even at dry year of 1387 and SPI index values were equal to -0.38 and -0.53 for Jolfa and Kaleybar stations respectively, that confirmed this matter. Statistical analysis showed that the highest correlation between agricultural and meteorological indices was in Jolfa station, where the highest mean amount of SPI index was 0.6.