A new framework for accurate drought monitoring: the Regional Ensembled Standardized Precipitation Evapotranspiration Index (RESPEI)

This study delves into the crucial aspects of effective drought assessment, emphasizing the need for precise and diverse meteorological variables in monitoring droughts. Theoretical underpinnings of long-distance measurement encompassing the aforementioned features of an early warning drought system are also presented. A new framework, namely the Regional Ensembled Standardized Precipitation Evapotranspiration Index (RESPEI), for regional drought monitoring is proposed. Empirical research using data from ten meteorological stations in Pakistan validates the efficiency of the proposed algorithm for accurate drought characterization, revealing significant disparities between the existing and proposed methods. Furthermore, this paper evaluates the usefulness of RESPEI and SPEI indices for regional drought evaluation and investigates the impact of global warming on drought assessment. Utilizing maximum precipitation and evapotranspiration data on a regional basis, k-component mixture distributions are applied to compute the indices for diverse time scales. The findings indicate that a K-component model is relevant for nearly all stations according to the Bayesian Informative Criteria (BIC) scores. The indices’ temporal variability is assessed and split into short, medium, and prolonged-drought evaluations, and a correlation analysis and statistical significance test are performed to assess the relationship between the indices. The proposed indices are deemed suitable for regional drought assessment based on the results. Lastly, trend analysis shows decreasing trends of droughts in most stations, except for Bunji and Chilas stations where a significant increasing trend is detected.