Spatiotemporal rainfall trend analysis and drought identification in agro-climatic zones of Odisha, Eastern India

Drought is the outcome of unequal rainfall distribution over time and space which negatively impacts agricultural productivity and social well-being. Analyzing the spatiotemporal drought variability in terms of intensity and magnitude is necessary for improving agricultural productivity. The main goal of the study is to analyze the long-term rainfall trend and measure the frequency and severity of droughts in 10 Agro-Climatic Zones (ACZs) of Odisha, India from 1988 to 2022. Secondary data sources, like rainfall data of Special Relief Commissioner (SRC), Standardized Precipitation-Evapotranspiration Index (SPEI) database, Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) data and GLDAS-2.2: Global Land Data Assimilation System data are used to achieve the objective. Moreover, field data is collected to validate drought scenario. In this study, Innovative Trend Analysis (ITA) is used to evaluate rainfall trends. Drought scenario mapping is done through Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI) method and various drought indices like Vegetation Condition Index (VCI), Temperature Condition Index (TCI), Precipitation Condition Index (PCI), and Integrated Drought Severity Index (IDSI). The study found highly increasing trend in rainfall in 2006–2022 compared to 1989–2005, over Eastern Ghat High Land (EGHL), Northwestern Plateau (NWP), North Central Plateau (NCP), and Northeastern Ghat (NEG). While moderately decreasing trend observed over Northeastern Coastal Plain (NECP) and Eastern and Southeastern Coastal Plain (ESECP). High drought frequency with extreme severity noticed over NECP, and severe over Western Undulating Zone (WUZ) and Western Central Table Land (WCTL). Low IDSI values reflecting severe drought effects which noticed over WCTL, WUZ and Mid Central Table Land (MCTL) in 2016, WCTL and ESECP in 2018 and MCTL, ESECP, and NCP in 2022. The study provides critical insights to the current scenario of knowledge of drought condition for better understanding the drought and agricultural planning in each ACZ of Odisha.