Assessment of Agricultural Drought Vulnerability Using Remote Sensing and GIS: A Case Study of Lower Cauvery Basin, Tamil Nadu, India

Abstract

AbstractMODIS satellite provides many data products, including MOD11A2 and MOD13Q1, for the assessment of agricultural drought in a region. This study area of the lower Cauvery basin of Tamil Nadu was affected by agricultural drought as a result of scanty rainfall in the period 2010–2015. To assess the drought condition in the study area over nearly six years (2010–2015), certain drought indices are used. These include the Normalised Difference Vegetation Index (NDVI) from MOD13Q1 data product and seasonal Land Surface Temperature (LST) from MOD11A2 data product. After calculation of NDVI and LST, three other indices were derived: Vegetation Condition Index (VCI), Temperature Condition Index (TCI), and Vegetation Health Index (VHI). The spatial variation in VHI was also analysed. From the study, a significant relationship was observed between NDVI and LST-decreasing NDVI and increasing surface temperature. Results show that nearly one-third of the lower Cauvery basin was affected by mid to severe drought. During the dry season (February to May), the severity of drought has increased both in terms of intensity and extent towards the north.