Differential Impact of Precipitation Trends on Water Security Across Iran's Heterogeneous Climatic Zones
Document Type : Research Paper
Authors
1 Postdoctoral Researcher in Climatology, Department of Physical Geography, University of Tehran, Teheran, Iran.
2 Department of Climatology Faculty of Geographical Sciences, Kharazmi University, Tehran, Iran.
3 Postdoctoral Researcher in Climatology, Department of Physical Geography,University of Sistan and Baluchestan, Zahedan, Iran.
4 Postdoctoral Researcher in Remote Sensing and GIS, Faculty of Literature, Ferdowsi University of Mashhad, Iran.
Abstract
Abstract
In the context of arid and semi-arid regions characterised by pronounced climatic heterogeneity, such as Iran, ensuring water security is inherently complex. However, monolithic, national-scale assessments frequently fail to capture the differential responses of distinct climatic zones to hydrological changes. This study addresses this gap by conducting a differential analysis of the impact of precipitation trends from 1970 to 2021 on the Aqueduct 4.0 water security index across Iran's diverse climatic zones, as defined by the Köppen-Geiger classification. Following the detection of precipitation trends using the Mann-Kendall test, an Analysis of Covariance (ANCOVA) model was employed to test the moderating effect of climate type on the relationship between these two variables. The findings indicated a statistically significant interaction effect between precipitation trend and climate type (p ≈ 0.03), thereby substantiating the central hypothesis of a heterogeneous water security response. In order to quantify the differential impact, a sensitivity index was calculated, which identified the Mediterranean (Csa), hot semi-arid (BSh), and hot desert (BWh) climates as the most vulnerable to precipitation variability, with sensitivity indices of 398, 190, and 185, respectively. Conversely, other climatic zones demonstrated minimal sensitivity, indicating enhanced resilience or the predominance of alternative factors, such as anthropogenic pressures, on the system. These findings emphasise the limitations of a universalised approach and underscore the necessity of formulating region-specific, climate-informed water management strategies to ensure sustainable water security in Iran.
Keywords
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