Detection of Climate Change Impacts on Precipitation and Temperature Parameters in the Kabul River Basin, Afghanistan Using the LARS-WG08 Model

جغرافیا و مخاطرات محیطی

Volume 14, Issue 2 - Serial Number 54, June 2025, Pages 68-87   

Document Type: Research Article

DOI: 10.22067/geoeh.2025.88181.1488

Authors

Abdul Aziz Qazizada^{* 1}; Kamal Omidvar²; Gholam Ali Mozaffari²; Ahmad Mazidi³

¹PhD Student in Climatology, Faculty of Geography, Yazd University, Yazd, Iran

²Professor in Climatology, Faculty of Geography, Yazd University, Yazd, Iran

³Associate Professor in Climatology, Faculty of Geography, Yazd University, Yazd, Iran

Abstract

One of the most contentious issues among contemporary climatologists is the existence of climate change and alteration in the trends of atmospheric parameters. The primary aim of this research was to examine the trends in precipitation and temperature changes under climate change conditions, and to predict future temperature and precipitation in the Kabul Drainage Basin, Afghanistan. To evaluate the impact of climate change on precipitation and temperature parameters, detection, trend analysis, prediction, and model accuracy analyses were conducted. In this process, methods such as anomalies, the non-parametric Mann-Kendall test, Theil-Sen's slope, the LARS-WG model (sixth report), and statistical indices such as the correlation coefficient, coefficient of determination (r, R²), RMSE, and NRMSE were used. The research findings indicate that in the Kabul Drainage Basin, the trends in these parameters are positive, with increasing annual average precipitation and increasing annual average temperature. The rainy season has gradually shifted from winter to summer. Specifically, the annual precipitation between 1979 and 2020 increased by approximately 0.30% or 0.93 mm, while the temperature increased significantly by about 8% (1.2°C). Predictions suggest that the trend of increasing temperature and decreasing precipitation will continue from the baseline period (1991–2021) into the 2021–2050 period. Across all scenarios SSP1-2.6, SSP2-4.5, and SSP5-8.5 the minimum temperature is projected to increase by 0.4°C, 0.5°C, and 0.6°C, respectively, and the maximum temperature by 0.6°C, 0.7°C, and 0.8°C compared to the baseline period. Annual precipitation is also expected to decrease by approximately 11% compared to the baseline period. Therefore, the impacts of climate change, including increased temperatures and altered precipitation patterns, are likely to exacerbate the risk of floods and related hazards in the future. The study of precipitation and temperature parameters under climate change is crucial. Accordingly, adaptation strategies for climate change and the enhancement of resilience are recommended.
Extended Abstract
Introduction
Climate change, as one of the most critical challenges of the present century, has had widespread effects on the environment, water resources, agriculture, and human livelihoods worldwide. It remains one of the most controversial topics in climatology. Most climatologists believe that changes in temperature or precipitation cannot simply be interpreted as long-term or short-term climatic fluctuations. Studies indicate that climate change is a global threat that disrupts the sustainability of various components of the Earth's system. Therefore, understanding current conditions and making climate projections are essential for identifying vulnerabilities and developing strategies to adapt to climate change.
Long-standing internal conflicts, diverse climates, complex topography, and a lack of meteorological stations have hindered extensive research in this field. To date, no comprehensive scientific studies have been conducted on precipitation and temperature trends in the Kabul Basin. While numerous global studies exist, research efforts in Afghanistan have been limited. Among the few studies in Afghanistan are those by Babar et al. (2016), Aliyar, Dhungana, and Shrestha (2022), Broomand (2015), Mestarshed (2013, 2014), Nasrati (2018), Sharafat (2020), and Salehi (2022). These studies indicate a declining trend in precipitation, particularly during spring and winter, and a rising trend in temperature across Afghanistan.
The Kabul River Basin, due to its unique geographical location and climatic conditions, has been significantly impacted by climate change, experiencing notable alterations in precipitation and temperature parameters. This region not only holds critical importance for water supply and agriculture for its inhabitants, but also warrants closer examination due to the frequent occurrence of floods and droughts. A detailed assessment of precipitation and temperature trends in the basin is essential.
The primary objective of this study is to investigate the impacts of climate change on precipitation and temperature variables and to forecast these parameters in the Kabul River Basin. This research employs various methods, including anomaly detection, the non-parametric Mann-Kendall test, Sen’s slope estimator, the LARS-WG model, and correlation coefficients, to analyze precipitation and temperature trends and address the existing research gap.
Material and Methods
This study utilized ground-based data from 28 meteorological stations over the period 1979–2020, as well as atmospheric data from NASA's MERRA-2 dataset. In 2021, missing precipitation and temperature data for the years 1979–2020 were completed by Japanese researchers using the gap-filling method. Due to the lack of daily ground-based precipitation and temperature data, daily precipitation and temperature records for 1991–2020 were downloaded from NASA's MERRA-2 platform. Missing and anomalous data were completed using statistical methods such as moving averages, and outliers were identified and removed using statistical tests like the Shapiro-Wilk test.
Analytical methods, including anomalies, the non-parametric Mann-Kendall test, Sen's slope estimator, and statistical indices such as the correlation coefficient (r), coefficient of determination (R²), RMSE, and NRMSE, were applied in the analysis. Trend analysis was conducted using the anomaly method (Equation 1) and the Mann-Kendall test (Equation 2). Using outputs from the Sixth Assessment Report of the IPCC and the LARS-WG8 model (HadGEM3-GC31-LL-CMIP6), climatic elements were projected for the 2021–2050 period. The validation of the results was conducted using statistical measures, including r, R², RMSE, and NRMSE (Equations 4, 5, and 6). Data analysis was performed using ArcGIS, Excel, and SPSS software.
Additionally, using validation indices such as the correlation coefficient (r), root mean square error (RMSE), and normalized root mean square error (NRMSE), along with observational precipitation and temperature data from five meteorological stations in the Kabul River Basin for the period 1991–2020, the outputs of the LARS-WG8 model were validated. The results confirm the satisfactory performance of the model in generating downscaled precipitation and temperature data.
Results and Discussion
The Mann-Kendall test, recommended by the World Meteorological Organization, was used in this study to analyze the annual rainfall trend. This statistical method is a standard approach for evaluating temporal trends in hydrological data. The results, presented in Table 2, indicate that during the period 1979–2020, the mean annual rainfall was 310 mm, with minimum and maximum values of 116 mm and 358 mm, respectively. Using a 95% confidence level (α = 0.05), the calculated Z-statistic for the Mann-Kendall test was 1.96, confirming a statistically significant increasing trend. An annual rainfall increase of 0.30% was observed in the Kabul River Basin.
Similarly, the trends in annual minimum, maximum, and mean temperatures were analyzed, as detailed in Table 3. The results reveal significant increases in all three temperature parameters. Specifically, the Mann-Kendall test showed that the annual minimum temperature exhibited the most pronounced trend, with a Z-value of 5.25, followed by significant increases in the annual mean and maximum temperatures. Analysis of the data in Table 2 confirms that all temperature types have risen considerably over the period 1979–2020.
Figure 5, based on Table 2, illustrates the temporal trend of annual mean temperature in the Kabul River Basin, highlighting a clear and substantial increase over the study period. These findings, combined with the lack of effective adaptation measures to address climate change, suggest that the observed trends are likely to continue. This ongoing temperature rise is expected to accelerate glacier melting, leading to a higher frequency of floods in the basin in the coming years.
Conclusion
The results of this study indicate that the annual precipitation in the Kabul Basin during the period 1979–2020 experienced an insignificant increase of approximately 0.3%, equivalent to 0.93 mm, while temperature exhibited a significant rise of nearly 8%, corresponding to an increase of 1.2°C. Projections suggest that the upward trend in temperature and the downward trend in precipitation will persist during 2021–2050 compared to the baseline period (1991–2021). Under all Shared Socioeconomic Pathway (SSP) scenarios—SSP1-2.6, SSP2-4.5, and SSP5-8.5—minimum temperatures are projected to increase by 0.4°C, 0.5°C, and 0.6°C, respectively, and maximum temperatures by 0.6°C, 0.7°C, and 0.8°C, respectively, compared to the baseline period. Additionally, annual precipitation is expected to decrease by approximately 11% relative to the baseline. The forecasts further suggest changes in the region’s precipitation regime, specifically a reduction in the proportion of precipitation occurring during colder months compared to other months. Consequently, the ratio of solid precipitation (snow) to liquid precipitation (rain) is projected to decline in the coming years.

Keywords

Climate Change; Climatic Trend Analysis; Temperature and Precipitation Variability; Mann-Kendall Test; LARS-WG Weather Generator; Kabul Basin

References

Aliyar, Q., Dhungana, S., & Shrestha, S. (2022). Spatio-temporal trend mapping of precipitation and its extremes across Afghanistan (1951–2010). Theoretical and Applied Climatology, 147(1-2), 605–626. https://doi.org/10.1007/s00704-021-03851-2

Azari, M., Moradi, H. R., Saghafian, B., & Faramarzi, M. (2016). Assessment of Hydrological Effects of Climate Change in Gourganroud River Basin. Water and Soil, 27(3), 537-547. [In Persian] https://doi.org/10.22067/jsw.v0i0.26051

Babar, Z. A., Zhi, X., Ge, F., Riaz, M., Mahmood, A., Sultan, S., … & Ahmad, M. F. (2016). Assessment of Southwest Asia surface temperature changes: CMIP5 20th and 21st century simulations. Pakistan Journal of Meteorology, 13(25), 1–15. https://www.prdb.pk/article/assessment-of-southwest-asia-surface-temperature-changes-cm-190

Baidar, K., Ihsan, I., Zahid, S., & Nabavi, S. A. (2024). Climate change and its impact on water resources and groundwater in Afghanistan. Nangarhar University International Journal of Bioscience. 344-347. http://dx.doi.org/10.70436/nuijb.v3i02.235

Beniston, M., Stephenson, D. B., Christensen, O. B., Ferro, C. A., Frei, C., Goyette, S., ... & Woth, K. (2007). Future extreme events in European climate: An exploration of regional climate model projections. Climatic Change, 81(1), 71-95. https://doi.org/10.1007/s10584-006-9226-z

Bromand, M. T. (2015). Impact assessment of climate change on water resources in the Kabul River Basin, Afghanistan. (Master’s thesis). Ritsumeikan University, Shiga, Japan, Environmental Systems and Civil Engineering.

Christensen, N. S., Wood, A. W., Voisin, N., & Lettenmaier, D. P. (2004). The effects of climate change on the hydrology and water resources of the Colorado River Basin. Climatic Change, 62(1-3), 337-363. https://doi.org/10.1023/B:CLIM.0000013684.13621.1f

Douville, H., Raghavan, K., Renwick, J., Allan, R. P., Arias, P. A., Barlow, M., ... & Zolina, O. (2021). Water cycle changes. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. https://centaur.reading.ac.uk/101319/1/101319.pdf

Ekström, M., Fowler, H. J., Kilsby, G. G., & Jones, P. D. (2003). New estimates of future changes in extreme rainfall across the UK using regional climate model integrations. Part 2: Future estimates and use in impact studies. Journal of Hydrology, 300(1-4), 234-251. https://doi.org/10.1016/j.jhydrol.2004.06.019

Ellison, D., Morris, C. E., Locatelli, B., Sheil, D., Cohen, J., Murdiyarso, D., ... & Sullivan, C. A. (2017). Trees, forests and water: Cool insights for a hot world. Global Environmental Change, 43, 51-61. https://doi.org/10.1016/j.gloenvcha.2017.01.002

Fowler, H. J., & Kilsby, C. G. (2007). Using regional climate model data to simulate historical and future river flows in northwest England. Journal of Climate Change, 80, 337-367. http://dx.doi.org/10.1007/s10584-006-9117-3

Frei, C., Schöll, R., Fukutome, S., Schmidli, J., & Vidale, P. L. (2006). Future change of precipitation extremes in Europe: Intercomparison of scenarios from regional climate models. Journal of Geophysical Research: Atmospheres, 111, D06105. http://dx.doi.org/10.1029/2005JD005965

Frich, P., Alexander, L. V., Della-Marta, P., Gleason, B., Haylock, M., Klein Tank, A. M. G., & Peterson, T. (2002). Observed coherent changes in climatic extremes during the second half of the twentieth century. Climate Research, 19(3), 193-212. https://doi.org/10.3354/cr019193

Hasanzai, F. H. (2022). Assessment and analysis of the impacts of climate change on water resources in five river basins of Afghanistan. (Master’s Thesis). Yazd University, Physical Climatology, Faculty of Physics. [In Persian]

 

 

Hedayat, S. J., Ebrahimi Khousfi, M., Omidvar, K., & Sharifi Pichon, M. (2024). Investigation of factors affecting surface and groundwater resources using satellite products (Case study: Kabul, Afghanistan). Journal of Water and Sustainable Development, 11(1), 13–24. [In Persian] https://doi.org/10.22067/jwsd.v11i1.2312-1291

IPCC. (2021). The physical science basis: Working Group I contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Chapter 11, 955-917. https://doi.org/10.1017/9781009157896.011

Mailhot, A., Duchesne, S., Caya, D., & Talbot, G. (2007). Assessment of future change in intensity-duration-frequency (IDF) curves for Southern Quebec using the Canadian Regional Climate Model (CRCM). Journal of Hydrology, 347(1-2), 197-210. https://doi.org/10.1016/j.jhydrol.2007.09.019

Mayar, M. A. (2020). River flow analyses for flood projection in the Kabul River Basin. Central Asian Journal of Water Research, 6(1), 1-17. http://dx.doi.org/10.29258/CAJWR/2020-R1.v6-1/1-17.eng

Mestarshed, M. (2013). Identifying rainfall and temperature characteristics in Afghanistan.(Master’s thesis). University of Isfahan, Faculty of Geographical Sciences and Planning. [In Persian].

Mestarshed, M. (2014). The climatic characteristics of Afghanistan’s rainfall. Geographical Research Quarterly, 29(3), 191–202. [In Persian] http://georesearch.ir/article-1-355-fa.html

Nasrati, R. (2018). Study of the recent half-century drought in the country. General Information and Communications Department, Academy of Sciences, Kabul, Afghanistan, 41–48 and 79–88. [In Persian]

Omidvar, K., & Khosravi, Y. (2010). Examination of changes in some climatic elements on the northern coasts of the Persian Gulf using the Kendall test. Journal of Geography and Environmental Planning, 21(2), 38. [In Persian] https://dor.isc.ac/dor/20.1001.1.20085362.1389.21.2.4.0

Parsa, S., Zarin, A., Mofidi, A., & Dadashi Rudbari, A. (2024). Impacts of climate change on temperature and precipitation in Afghanistan with emphasis on the Helmand and Harirod basins. Journal of Water and Sustainable Development, 11(1), 35–38. [In Persian] https://doi.org/10.22067/jwsd.v11i1.2312-1294

Pokhrel, Y., Felfelani, F., Satoh, Y., Boulange, J., Burek, P., Gädeke, A., ... & Wada, Y. (2021). Global terrestrial water storage and drought severity under climate change. Nature Climate Change, 11(3), 226-233. https://doi.org/10.1038/s41558-020-00972-w

Rahimi, D., & Zarei, F. (2019). Effects of climate change on the volume of water resources and inter-basin water transfer. Irrigation and Engineering Sciences (Scientific Journal of Agriculture), 42(3), 61–74. [In Persian] https://doi.org/10.22055/jise.2017.21862.1565

Rahmati, J., Darmel, M. B., Ullah, S., & Ghaforzai, A. (2024). Impacts of climate change on groundwater resources in Afghanistan: A case study of Kandahar Province. Nangarhar University International Journal of Bioscience, 291-295. http://dx.doi.org/10.70436/nuijb.v3i02.221

Raoufi, H., Taqwa, S., & Attayee, S. N. (2024). Temperature trend analysis: A case study of Kabul, Afghanistan. Meteorology, Hydrology and Water Management, 12(1). https://doi.org/10.26491/mhwm/194452 

Safi, A. G., & Rasikh, K. (2024). Climate change effects on the rivers of Afghanistan. Nangarhar University International Journal of Bioscience. 313-317. https://doi.org/10.70436/nuijb.v3i02.226

Salehi, F. A. (2022). Synoptic analysis of heavy snowfall events in Afghanistan. (Master’s thesis). Yazd University, Department of Geography, Atmospheric Sciences. [In Persian]

Sharafat, A. (2020). Synoptic study of maximum daily rainfall in Kabul Province. (Master’s thesis) Yazd University, Department of Geography, Atmospheric Sciences. [In Persian]

Sidiqi, M., & Shrestha, S. (2021). Assessment of climate change impact on the hydrology of the Kabul River Basin, Afghanistan. Journal of Water Engineering and Management, 2(1), 1–21. https://doi.org/10.47884/jweam.v2i1pp01-21

Souvignet, M., Gaese, H., Ribbe, L., Kretschmer, N., & Oyarzun, R. (2008). Climate change impacts on water availability in the arid Elqui Valley, North Central Chile: A preliminary assessment. In IWRA World Water Congress, Montpellier, France.

Steele-Dunne, S., Lynch, P., McGrath, R., Semmler, T., Wang, S., & Hanafin, J. (2008). The impacts of climate change on hydrology in Ireland. Journal of Hydrology, 356(1-2), 28-45. https://doi.org/10.1016/j.jhydrol.2008.03.025

Swain, D. L., Singh, D., Touma, D., & Diffenbaugh, N. S. (2020). Attributing extreme events to climate change: A new frontier in a warming world. One Earth, 2(6), 522-527. https://doi.org/10.1016/j.oneear.2020.05.011