Snow cover changes and affecting hydro-climate variables in Sabalan Mountainous region in Northwest Iran
نویسندگان
1 Department of Natural Resources, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
2 Department of Soil and Water Research, Qazvin Agricultural and natural Reources Research Center, Qazvin Province, Qazvin, Iran
3 Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran
doi
10.48308/esrj.2025.240655.1287چکیده
Snow, a key part of the water balance in mountains, supports flow in snow-fed streams. This study aims to investigate snow cover variations and the effects of hydro-climatic variables on it in the Sabalan mountain region of Ardabil province, Iran. Snow cover changes were assessed through interpretation of Landsat satellite images. The Mann-Kendall test analyzed trends in temperature, precipitation, and discharge, while Pearson correlation assessed their relationship with snow cover. The results showed that snow cover decreased by 12.7% in the period between 1991 and 2003, and by 65.1% for the study period (1991-2015). Discharge had a decreasing trend in all hydrometric stations except Lay station in December, with significant reductions observed at Pole-Soltani and Nir hydrometric stations at 99% and 95% confidence levels, respectively. Additionally, Meshgin-Shahr hydrometric station showed an increasing trend in December discharge, while precipitation at Nir rain gauge station in January increased significantly. Although the temperature of both Meshgin-Shahr and Nir meteorological stations increased, correlation analysis did not identify a significant relationship between snow cover and hydro-climatic variables in the region. The study reveals a significant decline in snow cover in the Sabalan mountain region, with a 65.1% reduction from 1991 to 2015, indicating potential impacts on water availability. Despite rising temperatures and varying trends in precipitation and discharge, no strong correlation was found between snow cover and hydro-climatic variables. This suggests that other factors, possibly local microclimates or land use changes, may influence snow dynamics. The results revealed the complexity of snow-hydroclimate interactions and the need for integrated monitoring to manage future water resources.