Spatiotemporal analysis of drought and its teleconnections over agro climatic zones of India

Understanding long-term spatiotemporal changes of drought and its linkage with climate modes is important from an agricultural perspective. Spatiotemporal trends of meteorological drought, quantified using the Standardized Precipitation Index (SPI), over Agro Climatic Zones (ACZs) of India from 1933–2022 were analyzed using the graphical Innovative Trend Analysis (ITA) along with traditional Mann-Kendall (MK)/modified Mann-Kendall (m-MK), Sen’s slope and simple linear regression. This study also analyzed the linkage between El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) with monsoon season meteorological drought over ACZs for 1903–2022. Variations in both SPI-4 of September and SPI-12 of December showed almost equal percentage of wet (SPI > 0, 49.9%) and dry (SPI < 0, 51.1%) years. Monsoon and annual drought frequencies varied from 12.5 to18.3%. The trend slopes of monsoon SPI-4 varied from − 0.14 to 0.11/10a, while the annual SPI-12 varied from − 0.14 to 0.19/10a. Long-term trends of both monsoon SPI-4 and annual SPI-12 showed significantly increasing drying tendencies in the central, northern and eastern parts of the country, while the peninsular India showed wetting trends, except in western coastal plains, where significant drying is observed. Monsoon SPI-4 in most ACZs was closely linked with ENSO (Niño 3.4 and SOI), while it showed almost no linkage to IOD (DMI). This suggests that the ENSO remains the dominant driver of drought variability in ACZs of India, whereas the IOD’s role appears marginal in modulating long-term drought risk. The outcomes of this work gives valuable insights for agricultural planning and water resource management strategies to mitigate drought risks in different ACZs of India.