Journal of New Approaches in Water Engineering and Environment
Scientific Journal

Assessment of Snow Cover (NDSI) Variations in the Maroon River Basin during 2001–2022 and Their Influence on the River’s Hydrological Regime

Document Type : Original Article

Authors

nezam tani
kamal Omidvar

Department of Meteorology, Faculty of Geographical Sciences, Yazd University, Yazd, Iran

10.22034/nawee.2025.556012.1175
Abstract
Objective: In mountainous regions of the Zagros, including the Maroon Basin in southwestern Iran, snow is the primary source of annual runoff. However, recent climatic changes, particularly rising temperatures and shifts in precipitation patterns, have altered the temporal and spatial distribution of snow accumulation and snowmelt. These changes have important implications for river hydrological regimes. Accordingly, this study investigates the temporal and spatial trends of snow cover and analyzes its relationship with Maroon River discharge over the period 2001–2022 to clarify the role of snow-cover changes in surface-flow dynamics.
Methods: River discharge data from the Idenak hydrometric station (upstream of Maroon Dam) were also used, and missing data were reconstructed using regression methods. To investigate the relationship between snow cover and river discharge, Pearson correlation analysis was performed for both simultaneous and lagged relationships. Since snowmelt in the Maroon Basin typically occurs from late winter to mid-spring, lag effects of up to two months were considered to capture delayed runoff responses associated with snowmelt. All analyses were conducted using ArcGIS, Excel, and SPSS software.
Results: The results showed a significant declining trend in snow cover during most months, particularly from January to March. Seasonal analysis also indicated a decreasing trend in snow-covered area during the snow season (October–May), with Z = −1.58 (p < 0.05). Sen’s slope estimates showed an average reduction of approximately 7.28 km² in snow-covered area per year during winter. Correlation analysis revealed the strongest positive relationship between NDSI and Maroon River discharge during the snowmelt period (March–May), both simultaneously and with time lags of one to two months, with correlation coefficients reaching 0.75.
Conclusions: The significant decline in snow cover and its strong correlation with river discharge, both simultaneously and with 1–2-month delays, indicate a reduction in snow persistence and earlier snowmelt in the Maroon Basin during the past two decades. These changes have altered the hydrological regime of the Maroon River.
This study, by combining long-term MODIS-based snow-cover trend analysis with simultaneous and lagged evaluation of the relationship between NDSI and river discharge at multiple temporal scales, provides a robust understanding of the dynamic relationship between snow-cover changes and surface-flow behavior in this critical basin.

Keywords

Snow Cover
Discharge
Trend
Correlation
Maroon River
 
Bahrami-Pichaghchi, H., Aghelpour, P., 2023. An estimation and multi-step ahead prediction study of monthly snow cover area, based on efficient atmospheric-oceanic dynamics. Climate Dynamics, 60(3), 743-765. https://link.springer.com/article/10.1007/s00382-022-06341-x (In Persian).
Bahrami Pichaghchi H, Norooz Valashedi R, Raeini-sarjaz M., 2022. Statistical Analysis of Time Series of Snow-Covered Area Obtained from Satellite Images in Mazandaran Province. J Watershed Manage Res. 13(25), 50-61. (In Persian). 10.52547/jwmr.13.25.50.
Bales Roger, C., Noah, P., Molotch Thomas, H., Painter Michael, D., Dettinger Robert Rice, Jeff Dozier., 2006. Mountain hydrology of the western United States. Water Resources Research 42, no. 8. https://doi.org/10.6071/M39Q2V.
Bousbaa, M., Boudhar, A., Kinnard, C., Elyoussfi, H., Karaoui, I., Eljabiri, Y., Chehbouni, A., 2024. An accurate snow cover product for the Moroccan Atlas Mountains: Optimization of the MODIS NDSI index threshold and development of snow fraction estimation models. International Journal of Applied Earth Observation and Geoinformation, 129, 103851. https://doi.org/10.1016/j.jag.2024.103851.
Eslami, H., Jamali, S., Ayoubi Kia, R., Eslami, K., 2022. Evaluating the performance of rainfall forecasting models in estimating discharge and flood volume using the developed NAM model (Case study: Western basins). New Approaches in Water and Environmental Engineering, 1(1), 101–112. https://doi.org/10.22034/nawee.2023.346025.1001(In Persian).
Chanda, N., Chintalacheruvu, M. R., Choudhary, A. K., 2024. Exploring climate-change impacts on streamflow and hydropower potential: insights from CMIP6 multi-GCM analysis. Journal of Water and Climate Change, 15(9), 4476-4498. https://doi.org/10.2166/wcc.2024.150.
Dargahian, F., Mousivand, Y., Razavizadeh, S., 2024. Snow monitoring in the upper reaches of the basin and its relationship with the changes in the water area of Hamoun using remote sensing. Jwmseir; 18 (64), 8. URL: http://jwmsei.ir/article-1-1105-fa.html (In Persian).
Faal, R., Saboori, M., Patro, E. R., Ala-Aho, P., Haghighi, A. T., 2025. A novel spatiotemporal analysis of snow cover pattern over Finland based on ERA5-land reanalysis. Journal of Hydrology, 134264. https://doi.org/10.1016/j.jhydrol.2025.134264.
Ghasemi, A. R., 2022. Investigation of snow cover changes in the Kouhrang region of Chaharmahal and Bakhtiari Province using Landsat satellite image processing, Innovative Research in Sustainable Water Engineering, 1(2), 13–25. https://doi.org/10.22103/nrswe.2023.20344.1015 (In Persian).
Gao, Z., Liu, Z., Han, P., Zhang, C., 2024. Investigating spatial-temporal trend of snow cover over the three provinces of Northeast China based on a cloud-free MODIS snow cover product. Journal of Hydrology, 645, 132044. https://doi.org/10.1016/j.jhydrol.2024.132044.
Ghasemi, A. R., 2022. Investigation of snow cover changes in the Kouhrang region of Chaharmahal and Bakhtiari Province using Landsat satellite image processing. New Researches in Sustainable Water Engineering, 1(2), 13–25. https://doi.org/10.22103/nrswe.2023.20344.1015. (In Persian).
Hall, D. K., Foster, J. L., Verbyla, D. L., Klein, A. G., Benson, C. S., 1998. Assessment of snow-cover mapping accuracy in a variety of vegetation-cover densities in central Alaska. Remote sensing of Environment, 66(2), 129-137. https://doi.org/10.1016/S0034-4257 (98)00051-0.
Hall, D. K., Riggs, G. A., Salomonson, V. V., DiGirolamo, N. E., Bayr, K. J., 2002. MODIS snow-cover products. Remote sensing of Environment, 83(1-2), 181-194. https://modis-snowice .gsfc. nasa.gov /uploads/ pap _ snowcover02.pdf
. Hiyama, T., Park, H., Kobayashi, K., Lebedeva, L., Gustafsson, D., 2023. Contribution of summer net precipitation to winter river discharge in permafrost zone of the Lena River basin. Journal of Hydrology, 616, 128797. https://doi.org/10.1016/j.jhydrol.2022.128797.
Kendall, M. G., 1975, Rank Correlation Methods. Griffin.
Khan, A. A., Li, X., 2025. Recent global snow cover trends using the MODIS dataset from 2000 to 2021. Remote Sensing Applications: Society and Environment, 101662. https://doi.org/10.1016/j.rsase.2025.101662.
Li, H., Li, H., Wang, J., Hao, X., 2020, Monitoring high-altitude river ice distribution at the basin scale in the northeastern Tibetan Plateau from a Landsat time-series spanning 1999–2018. Remote Sensing of Environment, 247, 111915. https://doi.org/10.1016/j.rse.2020.111915.
Maleki-Nejad, H., Soleimani Motlagh, M., Jaedari, A., Shater-Abshouri, S., 2012. Analysis of rainfall and drought trends using the Mann–Kendall test and Sen’s slope estimator in Tehran Province. Nivar, 37(80–81), 43–54. https://nivar.irimo.ir/article_13186.html (In Persian).
Mankin, Justin S., Daniel Viviroli, Deepti Singh, Arjen Y., Hoekstra, Noah S. Diffenbaugh., 2015. The potential for snow to supply human water demand in the present and future. Environmental Research Letters 10, no. 11, 114016. https://doi.org/2020031315141105.
Mann, H. B., 1945, Nonparametric tests against trend. Econometrica, 13(3), 245-259.
Mirabbasi Najafabadi, R., Dinpejouh, Y., 2010. Analysis of the trend of changes in the discharge of northwestern Iran Rivers in the last three decades. Water and Soil, 24(4), doi: 10.22067/jsw.v0i0.3901.
Mirmousavi, S. H., Heidari Monfared, Z., 2024. Spatio-temporal analysis of mean snow cover changes during the cold seasons in the northwest region of Iran. Nivar, 48(124–125), 84–104. https://doi.org/10.30467/nivar.2024.437745.1279. (In Persian).
Moazzam, M. F. U., Banerjee, A., Rahman, G., Lee, B. G., 2024. Elevation dependent climate assessment and its influence on snow cover variability in Hindu Kush Himalayan region using Google Earth Engine for the period of 2003–2021. Remote Sensing Applications: Society and Environment, 35, 101217. 10.1016/j.rsase.2024.101217.
Moradi, Ehsan., Zlatica Muchová, Hamid Darabi., Seyedeh Masoumeh., Hafezi, Zahra Karimidastenaei, Jana., Moravcová, Ali., Torabi, Haghighi., 2025. Assessment of snow cover dynamics and the effects of environmental drivers in High Mountain ecosystems. Environmental Impact Assessment Review 114, 107969. 10.1016/j.eiar.2025.107969.
Motiee, S., Motiee, H., Ahmadi, A., 2024. Analysis of rapid snow and ice cover loss in mountain glaciers of arid and semi-arid regions using remote sensing data. Journal of Arid Environments, 222, 105153. https://doi.org/10.1016/j.jaridenv.2024.105153.
Naghshine, M. H., Raof, F., Khoshrftar, A., 2013. The study of flood hydraulics before the building of Maroon Dam by HEC-RAS, Maskingam and Muskingum-Cunge method. https://ro.uow.edu.au/eispapers/1217.
Park, H., Kim, Y., Suzuki, K., Hiyama, T., 2024. Influence of snowmelt on increasing Arctic river discharge: numerical evaluation. Progress in Earth and Planetary Science, 11(1), 13. https://doi.org/10.1186/s40645-024-00617-y.
Sabzevari, Y., Dadavand, F., Nasrollahi, A., 2022. Monitoring temporal variations of meteorological drought in parts of western Iran. New Approaches in Water and Environmental Engineering, 1(2), 62–79. https://doi.org/10.22034/nawee.2022.361453.1025 (In Persian).
Serrano, A., Mateos, V.L., Garcia, A.J., 1999. Trend analysis of monthly precipitation over the librian for the period 1921-1995. Physics and chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere, 25(2), 85-90.
Shams, M., Mobasheri, M. R., Fatemi, S. B., 2014. Accuracy assessment of the NDSI index extracted from MODIS images in areas with moderate slope. Iranian Journal of Remote Sensing & GIS, 6(1), [pages not specified]. https://chatgpt.com/c/6936b52b-fa3c-8333-bdcc-bb885ff3b942. (In Persian).
Saifi, H., Ghorbani, E., 2019, Estimation of snow cover area using object-based techniques with OLI and TIRS sensor imagery: A case study of Sahand Mountain. Geographical Information (Sepehr), 28(109), 77–91. 10.22131/sepehr.2019.35639. (In Persian).
Tang, Z., Wang, X., Deng, G., Wang, X., Jiang, Z., Sang, G., 2020. Spatiotemporal variation of snowline altitude at the end of melting season across High Mountain Asia, using MODIS snow cover product. Advances in Space Research, 66(11), 2629-2645. 10.1016/j.asr.2020.09.035.
Tani, N., Omidvar, K., Mozaffari, G., Mazidi, A., 2025, Evaluation of the correlation between Karun River discharge and the snow cover index (NDSI) of the Karun basin using a statistical approach. Journal of Climatology Research, e226322. 10.22108/gep.2025.142875.1668.
Tani, N., Omidvar, K., Mazidi, A., Mozaffari, G., 2025. Detecting trends in snow cover (NDSI) changes in the Karun River Basin and the influence of regional and global teleconnection patterns on it. Iranian Journal of Remote Sensing & GIS. https://doi.org/10.48308/gisj.2025.236231.1223.
Thiel, H., 1950. A Rank-invariant Method ofLinear and Polynomial Regression Analysis, Part 3. Proceedings of Koninalijke NederlandseAcademic van Weinenschatpen A. 53,1397-1412.
Vivekanandan, N., 2007. Analysis of Trend in Rainfall Using Non Parametric Statistical Methods. International Symposium on Rainfall Rate and Radio Wave Propagation, American Institute of Physics, pp. 101-113. 10.1063/1.2767019
Vydra, C., Dietz, A. J., Roessler, S., Conrad, C., 2024. The Influence of Snow Cover Variability on The Runoff in Syr Darya Headwater Catchments between 2000 and 2022 Based on the Analysis of Remote Sensing Time Series. Water, 16(13), 1902. https://doi.org/10.3390/w16131902
Zhang, Q., Xiao, M., Singh, V. P., Chen, X., 2013. Copula-based risk evaluation of droughts across the Pearl River basin, China. Theoretical and Applied Climatology, 111(1), 119–131. DOI: 10.1007/s00704-012-0656-4.
Journal of New Approaches in Water Engineering and Environment
Volume 5, Issue 2
Summer 2026
Pages 84-100

Home

Guide for Authors

Submit Manuscript

Reviewers

Contact Us