Monitoring and assessing 2016 drought in Tamil Nadu: Remote sensing-based NDVI and NDWI

In the recent year drought studies has attracted more attention. Drought exerts major impact on agricultural and environmental systems. In this study, we examined the widely used drought indices viz., Normalized Difference Vegetation Index (NDVI) and, Normalized Difference Water Index (NDWI), which has been derived from remote sensing based Moderate Resolution Imaging Spectro-radiometer (MODIS) product at 500 m spatial resolution with 16 days temporal scale in various agro-climatic divisions across Tamil Nadu to monitor and asses the drought during the period of Northeast monsoon (October-December) in 2016. This study revealed that, among the agro climatic zones, Southern Zone registered the largest area of 1, 60, 500 ha under stressed condition followed by Western zone with an area of 1, 49, 200 ha. North Western zone and High Rainfall zone recorded the least area of 64, 275 and 50 ha under stressed condition, respectively. The least area under stressed condition was recorded in High Rainfall Zone (11, 225 ha) according to the NDWI classification. It has been observed that NDWI value range appears to show a slightly decreasing variation compared to NDVI value range for agro-climatic zones.