Assessment of Impact of Climate Change Towards Agricultural Drought Using Remote Sensing Indices in Semi-Arid and Humid Regions of South India

Agricultural drought being one of the worst consequences of climate change highly impacts the world’s food security. To understand the drought dynamics, continuous monitoring of climatological parameters is essential. Remote sensing-based drought indices are being utilised for the successful drought monitoring in various climatic zones. This study focuses on agricultural drought monitoring in two river basins of South India, belonging to Tamil Nadu (Thamirabarani river basin) and Kerala (Keecheri river basin). Both river basins are situated in two different climatic zones, i.e., semi-arid region and humid region respectively. As the agricultural activities in these river basins highly depend on rainfall, fluctuations in monsoon pattern (Southwest and Northeast), climate change will cause decrease in agricultural productivity of these basins. The main objective of this research is to observe the agricultural drought dynamics in both river basins and analyse the impact of agricultural drought. This study utilises various indices such as Vegetation Condition Index (VCI), Normalised Difference Vegetation Index (NDVI), Normalised Difference Water Index (NDWI) and Normalised Difference Moisture Index (NDMI) to monitor agricultural drought in both river basins from 2014 to 2023 using Landsat and Sentinel data. A multi-criterion weighted overlay approach was carried out and the results show that in both the basins, more than 60% of the area falls under mild drought during the study period. Occurrence of deficit rainfall during the years 2016 and 2019 has increased the area falling under mild drought in both Thamirabarani and Keecheri river basins respectively.