اشتقاق مؤشر الهطول المعياري (SPI) من بيانات الأمطار اليومية المعتمدة على الأقمار الصناعية (CHIRPS) باستخدامGoogle Earth Engine  لرصد الجفاف في العراق

Deriving SPI from Satellite-Based CHIRPS Daily Precipitation Using Google Earth Engine for Drought Monitoring in Iraq

Section: Article
Issue
Vol. 6 No. 24 (2026): Volume 6 / Issue 24

Abstract

The phenomenon of drought is one of the most persistent hydroclimatic hazards affecting arid and semiarid regions and Iraq is highly vulnerable as it is highly dependent on winter precipitation with limited continuous ground-based observational data. Despite a noticeable increase in the literature on drought in the Middle East, thorough long-term and spatially explicit assessments of meteorological drought in Iraq are rather limited; previous studies largely rely on station-based analyses limited in spatial extent or on short term data sets that poorly reflect multiperiod variability.


To fill this gap, the current study assesses meteorological drought in Iraq using the Standardized Precipitation Index (SPI) based on satellite-based CHIRPS Daily Precipitation data that was assimilated within the Google Earth Engine (GEE) platform. SPI calculations were performed at 3, 6, and 12-month accumulation scales for 41 water years (1983/84-2023/24), which also ensured that calculations followed the dynamics of water years in the region. Two complementary analytical approaches were used: (i) an aggregate national SPI time series to examine temporal variability and long-term drought phases, and (ii) a pixel-based SPI framework to determine spatial heterogeneity, areal extent and recurrence of drought and wetness classes.


The results show strong expeditionary yearly and by distinctive dry and wet regimes. The water years 2007/08 and 2011/12 are identified as the most severe and spatially extensive drought events, while the year 2018/19 is a typical example of an extremely wet period with widespread positive anomalies. Short-term SPI (SPI-3) records seasonal fluctuations of drought, the medium-term SPI (SPI-6) reflects the propagation of drought conditions, and the long-term SPI (SPI-12) can detect prolonged hydrological stress and recovery phases.


Overall, the integration of CHIRPS Daily precipitation with cloud-based processing provides a reproducible and operational drought-monitoring framework suitable for data-scarce regions, offering valuable support.

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Author

خضر رشيد عبدالرحمن الحكيم

Department of Geography/College of Education for Humanities/University of Mosul

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DOI: 10.33899/jeh.v6i24.60613

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اشتقاق مؤشر الهطول المعياري (SPI) من بيانات الأمطار اليومية المعتمدة على الأقمار الصناعية (CHIRPS) باستخدامGoogle Earth Engine  لرصد الجفاف في العراق: Deriving SPI from Satellite-Based CHIRPS Daily Precipitation Using Google Earth Engine for Drought Monitoring in Iraq. (2026). Journal of Education for the Humanities , 6(24). https://doi.org/10.33899/jeh.v6i24.60613

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خضر رشيد عبدالرحمن الحكيم (Department of Geography/College of Education for Humanities/University of Mosul)

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اشتقاق مؤشر الهطول المعياري (SPI) من بيانات الأمطار اليومية المعتمدة على الأقمار الصناعية (CHIRPS) باستخدامGoogle Earth Engine  لرصد الجفاف في العراق: Deriving SPI from Satellite-Based CHIRPS Daily Precipitation Using Google Earth Engine for Drought Monitoring in Iraq. (2026). Journal of Education for the Humanities , 6(24). https://doi.org/10.33899/jeh.v6i24.60613