Integrated assessment using AHP-PDSI-GIS of environmental sensitivity and drought in Diyala Governorate

Abstract

This research highlights the local climatic classification of Diyala Governorate, located in southeastern Iraq, which is classified globally as having a semi-arid climate. The governorate is generally characterized by diverse topographical features, ranging from wetlands such as Lake Hamrin and the Diyala River and its main and tributaries to barren lands. Therefore, climatic data for the period 1991–2024 were utilized to establish criteria and enhance the accuracy of the results before analysis, using ground-based standard stations in Khanaqin, Al-Khalis, and Badra. The Palmer Drought Severity Index (PDSI) was applied as a more accurate climatic parameter to determine arid and wet conditions during the study period. The research revealed that the region was affected by two contrasting seasons: a very dry period in 2013–2014 and a very wet period in 2023–2024. To analyze the temporal and spatial variations in drought, the Palmer index results were calibrated using Landsat 7–8 satellite imagery to track changes, and some further research was conducted.  Digital processing and enhancements were achieved by applying these indicators, including the Vegetation Cover Inde), Natural Water Index, Salinity Index, and Surface Area Index These results were then examined for relative weights, and the network satellite image was converted into a digital format using GIS tools and the Analysis Hierarchy Process (AHP), in accordance with Palmer characteristics. The results were then matched with Arc Map 10.8 software. A comparative project was implemented between related models and the spatial matching process between two indices: the PDSI and the AHP results. This revealed two types of environmental sensitivity during the severe drought season of 2013: semi-humid in several districts and sub-districts such as Khanaqin, Al-Muqdadiyah, Baqubah, Khan Bani Saad, and Al-Khalis, and arid in the areas of Kifri, Al-Adhaim, Qazaniyah, Mandali, and Baladruz. In 2024, the PDSI index recorded climatic patterns including humid, arid, and semi-humid.  The spatial matching between the Palmer Indices (PDSI) and the Analytical Hierarchy System (AHP) revealed five environmental sensitivity patterns in the region: humid, dry, semi-humid, semi-arid, and very dry. The districts of Al-Muqdadiyah and Baqubah fell within the semi-humid pattern, while Jalawla was within the humid pattern. The districts of Kifri, Khanaqin, Baladruz, Qazaniyah, Mandali, and Al-Khalis exhibited different patterns within these classifications.