Payame Noor University Journal of Urban Ecology Researches 2538-3930 15 4 2024 12 21 Monitoring and Evaluation of Snow Cover Changes Trend in the Cities of Golestan, Mazandaran and Gilan Provinces Monitoring and Evaluation of Snow Cover Changes Trend in the Cities of Golestan, Mazandaran and Gilan Provinces 23 40 9687 10.30473/grup.2023.66285.2749 FA Ata Ghafari Gilandeh Professor, Department of Geography and Urban Planning, University of Mohaghegh Ardabili, Ardabil, Iran. Vahid Safarian Zengir Ph.D. Department of physical Geography, Climatology, University of Mohaghegh Ardabili, Ardabil, Iran Journal Article 2022 12 06 In the current research, based on the data of the satellite images of the MODIS sensor, located on the Terra and Aqua satellites and the GRACE gravimetric satellite, with the innovative approach of algorithm and coding in the web system of Google Earth Engine in the cities of the provinces (Golestan, Mazandaran and Gilan) and within the interval of years 2001 to 2022; Estimation and analysis of changes trend in snow surface area, snow depth, snow equivalent water and groundwater aquifer changes in the studied area were done. According to the obtained results, the highest surface area of snowfall with a value of 9496.01 Km2 occurred in 2005 and the lowest with a value of 2906.21 Km2 in 2010, while the maximum amount of snow depth with a value of 0.07 meters in 2008 and the highest water equivalent of snow was obtained with a value of 10 kg/m2 in 2008, and this shows the high correlation between snow depth and water equivalent of snow. The results of the investigation of the groundwater aquifer based on the three CSR, GFZ and JPL models in the studied years showed that the maximum volume of the groundwater aquifer with a value of 12.5 cm was in 2005 and the lowest with a value of -27.5 cm is in 2017. The findings of the research show the decreasing trend of the groundwater aquifer in 2017 with the value of -12.5 cm in connection with the decreasing trend of snow cover in 2017 with the amount of snow cover of 5432.56 Km2 in the study area. Based on the results obtained from the present research, it can be concluded that the process of snow cover changes had an effect on the volume of the groundwater aquifer in the studied area. In the current research, based on the data of the satellite images of the MODIS sensor, located on the Terra and Aqua satellites and the GRACE gravimetric satellite, with the innovative approach of algorithm and coding in the web system of Google Earth Engine in the cities of the provinces (Golestan, Mazandaran and Gilan) and within the interval of years 2001 to 2022; Estimation and analysis of changes trend in snow surface area, snow depth, snow equivalent water and groundwater aquifer changes in the studied area were done. According to the obtained results, the highest surface area of snowfall with a value of 9496.01 Km2 occurred in 2005 and the lowest with a value of 2906.21 Km2 in 2010, while the maximum amount of snow depth with a value of 0.07 meters in 2008 and the highest water equivalent of snow was obtained with a value of 10 kg/m2 in 2008, and this shows the high correlation between snow depth and water equivalent of snow. The results of the investigation of the groundwater aquifer based on the three CSR, GFZ and JPL models in the studied years showed that the maximum volume of the groundwater aquifer with a value of 12.5 cm was in 2005 and the lowest with a value of -27.5 cm is in 2017. The findings of the research show the decreasing trend of the groundwater aquifer in 2017 with the value of -12.5 cm in connection with the decreasing trend of snow cover in 2017 with the amount of snow cover of 5432.56 Km2 in the study area. Based on the results obtained from the present research, it can be concluded that the process of snow cover changes had an effect on the volume of the groundwater aquifer in the studied area. https://grup.journals.pnu.ac.ir/article_9687_f6e8fd1d100f21ac68e24675e077ccc8.pdf