Climate change and recurrent extreme climatic events have intensified the vulnerability of water-stressed regions like Tunisia to droughts, severely impact agriculture, the economy, and society. This study analyzes hydro-meteorological drought patterns using the Gravity Recovery and Climate Experiment (GRACE) satellite-derived Groundwater Drought Index (GGDI), alongside traditional indices, including Standardized Precipitation Index (SPI), Standardized Precipitation-Evapotranspiration Index (SPEI), and Standardized Runoff Index (SRI). A stochastic analysis of monthly SPEI-GGDI values was conducted using a first-order Markov chain model, to investigate regional drought hazards formation, persistence, and evolution. Pearson’s correlation coefficient and wavelet coherence were applied to evaluate interactions among indices and their teleconnections with large-scale climate patterns. Results reveal persistent droughts, with extreme events exhibiting high stability and low recovery probabilities. The most severe groundwater drought occurred in 2014–2015, averaging a GGDI value of −1.36, while 2002–2003 was the driest based on SPEI, SPI, and SRI, averaging −1.9. Correlation analysis highlights complex interactions between meteorological and hydrological droughts, with GDDI-identified droughts exhibit greater severity in frequency, intensity, and duration, indicating significant anthropogenic influence. El Niño-Southern Oscillation (ENSO) significantly influenced drought evolution, with intense negative phases exacerbating severity.This study highlights the potential of GRACE satellite data for integrated drought monitoring and provides novel insights for developing sustainable drought management strategies in Tunisia.

中文翻译：

---

使用基于小波的定量方法对水文气象干旱及其可能的遥相关机制进行基于 Grace 的评估


气候变化和反复发生的极端气候事件加剧了突尼斯等缺水地区对干旱的脆弱性，严重影响了农业、经济和社会。本研究使用重力恢复和气候实验 （GRACE） 卫星衍生的地下水干旱指数 （GGDI） 以及标准化降水指数 （SPI）、标准化降水蒸散指数 （SPEI） 和标准化径流指数 （SRI） 等传统指数分析了水文气象干旱模式。使用一阶马尔可夫链模型对每月 SPEI-GGDI 值进行随机分析，以研究区域干旱灾害的形成、持续和演变。应用 Pearson 相关系数和小波相干性来评估指数之间的交互作用及其与大尺度气候模式的遥相关。结果显示持续干旱，极端事件表现出高稳定性和低恢复概率。最严重的地下水干旱发生在 2014-2015 年，平均 GGDI 值为 -1.36，而根据 SPEI、SPI 和 SRI 计算，2002-2003 年是最干燥的，平均为 -1.9。相关性分析突出了气象和水文干旱之间的复杂相互作用，GDDI 确定的干旱在频率、强度和持续时间方面表现出更严重的程度，表明存在显着的人为影响。厄尔尼诺-南方涛动 （ENSO） 显著影响了干旱演变，强烈的负阶段加剧了干旱的严重性。本研究强调了 GRACE 卫星数据在综合干旱监测方面的潜力，并为在突尼斯制定可持续的干旱管理战略提供了新的见解。