Akademik Veri Yönetim Sistemi
Biotechnology, Agronomy, Society and Environment, cilt.29, sa.2, ss.117-134, 2025 (SCI-Expanded, Scopus)
Description of the subject. Drought indices are essential for monitoring drought since they simplify the complex climate functions and quantify climatic variance for their severity, duration, and frequency. The drought index calculator (DrinC) software is useful for monitoring the meteorological drought by calculating drought indices. Objectives. The main objective of this study is to use some drought indices such as SPI, RDI, and RD to monitor the severity of drought in a Mediterranean region of Türkiye, the province of Isparta, using DrinC Software. Method. The research work considered the period from 1960 to 2021 in order to calculate the indices such as standardized precipitation index (SPI), reconnaissance drought index (RDI), and rainfall deciles (RD). The software was used to facilitate the calculation of the indices considered in the study, which are specifically based on the gamma method over 3, 6, 9, and 12 months. Results. The results revealed that the years 1984, 1999, and 2015 recorded SPI-3 values of-1.51,-2.11, and-2.03, respectively. Additionally, the years 1989 and 1999 exhibited SPI values of-1.62 and-2.26, respectively. For SPI-9, the years 1999 and 2007 showed values of-1.66 and-1.51, respectively. Moreover, SPI values of-1.51,-1.68, and-1.94 were noted in the years 1988, 1989, and 1999, respectively. Results for the Rainfall Deciles method showed that, among 61 years, 12 years were affected by drought (lowest %20 much below normal), and the most affected years were 1972-1973, 1988-1989, 1989-1990, 1992-1993, 1999-2000, and 2007-2008. The R2 value of 0.95 showed that annual SPI and annual RDI were highly correlated, and the linear regression fit well. Conclusions. This study highlights the effectiveness of using indices such as SPI, RDI, and RD, for assessing meteorological drought in Isparta over 60 years. Results show varying drought severity and frequency across indices, with SPI identifying more extreme droughts. Strong correlations between SPI and RDI confirm their reliability, while the Pettitt test indicates a major breakpoint in 1970. The findings emphasize the need for multi-index approaches and integrating additional measures like soil moisture to improve drought monitoring and management strategies.