Pollution

Pollution

Spatial and Temporal Changes in Vegetation Cover in Response to Extreme Climatic Phenomena in Arid Environments: Using Remote Sensing in Ramadi, Iraq (2024-1980)

Document Type : Original Research Paper

Authors
Naqeeb Abbas Hammad
Natheer Sbar Hamad
Department of Geography, College of Education for Humanities, University of Anbar, Iraq
10.22059/poll.2026.416361.3378
Abstract
Arid and semi-arid ecosystems face severe threats from climate extremes, yet the underlying physiological mechanisms driving long-term vegetation collapse remain under-researched in Western Iraq. This study quantifies the impact of climate change on vegetation dynamics in Ramadi over a 44-year period (1980–2024). Using a hybrid approach, long-term climate time-series data were evaluated via the non-parametric Mann-Kendall test and Sen’s slope estimator, while Landsat satellite imagery (1993 and 2024) was processed using NDVI to track phenological changes during the peak growing season (January) and dry season (July). Statistical analysis revealed a significant progressive warming trend (Z=+4.82, p<0.0001), with mean annual maximum temperatures increasing at a rate of 0.044 oC/year, amounting to a cumulative rise of 1.9 oC. This thermal shift was compounded by a statistically significant rainfall decline of -1.82 mm/year (Z=-2.15, p=0.031) and an unprecedented surge in annual evaporation of +14.5 mm/year (Z=+3.95, p=0.0001). Satellite observations showed a dramatic breakdown in ecological resilience: dense winter vegetation cover plummeted from 49.7% in 1993 to just 6.3% in 2024, while summer desertification expanded barren land to dominate 69.4% of the area. Strong statistical correlations confirmed these trends, showing NDVI positively linked to precipitation (r=0.82) and inversely tied to temperature (r=-0.78). The study indicates that this structural degradation is driven by synergistic heat-drought stress; elevated vapor pressure deficits (VPD) force prolonged stomatal closure, triggering carbon starvation and hydraulic failure. These findings demonstrate that the ecosystem has breached a critical resilience threshold, requiring immediate, targeted conservation interventions.
Keywords
Vapor Pressure Deficit (VPD)
Hydro-climatic Trends
Euphrates Basin
Eco-hydrological Collapse
Land Degradation
Sen's Slope
Subjects
Al-Ansari, N., & Adamo, N. (2018). Present water crises in Iraq and its human and environmental implications. Engineering, 10(6), 305–319. https://doi.org/10.4236/eng.2018.106021
Al-Jibouri, M. K., & Al-Mukhtar, M. M. (2025). Microclimatic deterioration and land degradation dynamics along transitional desert plateaus in Western Iraq. Journal of Arid Environments, 212, 104921.
Al-Kaisi, A. H., & Al-Bakri, J. T. (2024). Multi-temporal Landsat analysis of land cover change in Mesopotamian agricultural basins. International Journal of Remote Sensing, 45(8), 2650–2672.
Al-Kaisi, A. H., & Al-Jiboori, M. K. (2025). Regional temperature trends and thermal homogeneity across western Iraq (1980–2024). Theoretical and Applied Climatology, 156(2), 889–904.
Al-Quraishi, A. M. F., Gaznayee, H. A., & Crespi, M. (2021). Drought trend analysis in a semi-arid area of Iraq based on normalized difference vegetation index, normalized difference water index and standardized precipitation index. Journal of Arid Land, 13(4), 413–430. https://doi.org/10.1007/s40333-021-0064-2
Buringh, P. (1960). Soils and soil conditions in Iraq. Ministry of Agriculture.
Cheng, L., Wang, Y., & Zhang, H. (2026). Atmospheric vapor pressure deficit surges as key drivers of plant mortality under extreme drought. Global Change Biology, 32(2), e17890.
Fattah, M. Y., Hameedi, M. K., & Aswad, M. F. (2017). Determination of collapse potential of gypseous soil from field and laboratory tests. Diyala Journal of Engineering Sciences, 10(2), 75–85.
Gehad, T. Y., Omer, N. Q., & Abdulmajeed, N. S. (2024). Methodology for using multi-temporal Landsat images to monitor urban growth of Kirkuk Governorate. Journal of Techniques, 6(2), 1–12. https://doi.org/10.51173/jt.v6i2.1915
Groover, A., Liu, X., & Martinez, C. (2025). Tree drought physiology: Critical research questions and strategies for mitigating climate change effects on forests. New Phytologist, 245(1), 112–128. https://doi.org/10.1111/nph.20326
Hamed, M., Vicente-Serrano, S. M., & Zeleke, T. (2026). Non-linear thermal anomalies and land degradation tipping points in semi-arid ecosystems. Nature Climate Change, 16(3), 241–252.
Hammad, N. A. (2023). Physiological response of vegetation to thermal stress in arid zones. Iraqi Journal of Agricultural Sciences, 54(3), 780–792.
Hazim, R. T., & Abbas, S. H. (2025). Multi-decadal root-zone soil moisture depletion and environmental flow deficits in the Euphrates River Basin. Hydrological Processes, 39(4), e15120.
IPCC. (2023). Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (H. Lee & J. Romero, Eds.). Intergovernmental Panel on Climate Change. https://doi.org/10.59327/IPCC/AR6-9789291691647
Iraqi Ministry of Planning. (2024). Annual statistical abstract: Environmental conditions (2023–2024). Central Statistical Organization.
Jensen, J. R. (2015). Introductory digital image processing: A remote sensing perspective (4th ed.). Pearson Education.
Kendall, M. G. (1975). Rank correlation methods (4th ed.). Charles Griffin.
Khalaf, S. A., & Hassan, R. K. (2025). Remote sensing appraisal of vegetation dynamics and land cover shifts in Central Iraq. Remote Sensing Applications: Society and Environment, 37, 101450.
Lillesand, T. M., Kiefer, R. W., & Chipman, J. W. (2015). Remote sensing and image interpretation (7th ed.). John Wiley & Sons.
Liu, Y., Zhang, X., & Wang, L. (2024). Hydraulic failure mechanisms in desert vegetation under extreme warming events. Global Change Biology, 30(1), e17012. https://doi.org/10.1111/gcb.17012
Mann, H. B. (1945). Non-parametric tests against trend. Econometrica, 13(3), 245–259.
Miyan, M. A. (2025). Extreme climate vulnerability in MENA region: Hydro-climatic stress and adaptation strategies. Environmental Science & Policy, 163, 103910.
Mohammed, K. S., & Al-Bayati, A. M. (2025). Surface energy imbalances and localized dust emission fronts along Euphrates agricultural corridors. Catena, 248, 108510.
Mutar, Z. F., & Hamad, N. S. (2024). Estimating long-term trends in climatic elements and their impact on environmental degradation in Anbar Province. University of Anbar Journal for Humanities, 21(1), 112–130.
Pravalie, R. (2024). Arid ecosystem responses to accelerated global warming: A synthesis of spatial-temporal dynamics. Earth-Science Reviews, 248, 104630.
Rouse, J. W., Haas, R. H., Schell, J. A., & Deering, D. W. (1974). Monitoring vegetation systems in the Great Plains with ERTS. In Third Earth Resources Technology Satellite-1 Symposium (Vol. 1, pp. 309–317). NASA Goddard Space Flight Center.
Sardar, A. A. (2023). Ecological resilience assessment of semi-arid ecosystems in Western Iraq. Journal of Environmental Science and Management, 26(2), 45–58.
Sayel, A. H., Mahmoud, M. A., & Al-Suhail, Q. (2025). Hydrological regime disruption along the Euphrates River: Transboundary impacts and strategic storage responses. Journal of Hydrology: Regional Studies, 57, 101620.
Sen, P. K. (1968). Estimates of the regression coefficient based on Kendall’s tau. Journal of the American Statistical Association, 63(324), 1379–1389.
UNEP. (2022). Adaptation gap report 2022: Too little, too slow – Climate adaptation failure puts world at risk. United Nations Environment Programme. https://doi.org/10.59117/20.500.11822/41126
UNESCO. (2024). Water management and hydro-ecological vulnerability along the Tigris-Euphrates River System. UNESCO Publishing.
Vicente-Serrano, S. M., Beguería, S., & Lorenzo-Lacruz, J. (2025). Compound atmospheric water deficits and eco-hydrological collapse in arid lands. Environmental Research Letters, 20(2), 024015.
Pollution
Volume 12, Issue 4
Autumn 2026
Pages 1172-1184