Title: Sensitivity analysis of different aridity indices in the Iraq region

Authors: Omar M.A. Mahmood Agha

Addresses: Department of Dams and Water Resources Engineering, University of Mosul, Mosul, Iraq

Abstract: This study seeks to explore the sensitivity of different aridity indices of Iraq to climatic variables such as precipitation, temperature, and evapotranspiration. Different aridity indices such as Lang, De Martonne, Erinç, UNESCO, and UNEP indices were applied in the assessment of dryness in various regions of Iraq. Sensitivity analysis was done to assess the impact of a variation in climatic factors like rainfall, temperature, and evapotranspiration on the aridity indices. Sensitivity from the standard deviations of the variables was applied to ascertain its impact on the aridity index. The analysis revealed that rainfall had the highest impact with sensitivity coefficients ranging from 0.31 to 0.66. The temperature sensitivity ranged between the relatively low values of 0.02 to 0.07. The study concluded that the UNEP index was best to represent aridity in Iraq because it is more sensitive to climatic variables, especially evapotranspiration.

Keywords: sensitivity; aridity; Iraq; precipitation; temperature; evapotranspiration; UNEP; Lang; De Martonne; UNESCO.

DOI: 10.1504/IJHST.2026.152174

International Journal of Hydrology Science and Technology, 2026 Vol.21 No.2, pp.209 - 223

Received: 02 Apr 2025
Accepted: 01 Aug 2025
Published online: 10 Mar 2026 *

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