Prototype Framework for Agricultural Drought Monitoring in Northern Thailand Using Satellite-Based Evaporative Stress Index

Agricultural drought threatens crop production in Northern Thailand, where complex terrain and limited meteorological stations restrict effective ground-based monitoring. This study developed a prototype framework for agricultural drought monitoring using the satellite-based Evaporative Stress Index (ESI). Bias-corrected reference evapotranspiration (ETo) from TerraClimate was combined with satellite-derived actual evapotranspiration (ETa) from SSEBop to calculate 10-day ESI values during 2012–2023. A classification system based on consecutive ESI patterns was developed to generate action-oriented maps for emergency response. Temporal analysis revealed persistent agricultural drought from late 2021 through early 2022. Spatial analysis identified significant heterogeneity across the region, revealing localized stress areas that regional averages failed to detect. The consecutive-period classification prioritized areas under constant stress requiring emergency intervention over those experiencing only temporary fluctuations. Overall, the proposed prototype framework provides decision-support capabilities that can be integrated with exposure and resistance factors to guide resource allocation in regions with sparse ground-based monitoring infrastructure.