Simulations of past and future conditions of the Quaternary glaciers of Gharaghom Basin in Iran

Climate change is a global issue that has far-reaching impacts on our planet, including the melting of glaciers and changes in water resources. Gharaghom basin in northeastern Iran is one such region that is facing the consequences of climate change. This research has mapped the quaternary equilibrium line altitude (ELA) using Whrite’s and Porter’s methods to reconstruct past and present temperatures using a regression model. The potential impact of climate change on glaciers was detected by using an artificial neural network. The regression model established a relationship between temperature and altitude, revealing a temperature lapse rate of -۰.۴۱°C per hundred meters of increasing altitude. The reconstruction of past temperatures indicated a significant increase in mean annual temperature during the Pleistocene compared to the current temperature in the basin. The recent ELA has risen to approximately ۲۲۳۶ m and ۲۲۰۰ m a.s.l., respectively, from the Pleistocene levels. The use of an artificial neural network projected linear temperature growth for the next three decades in the Gharaghom basin. Trend analysis indicates that minimum temperatures have been more significantly affected by global warming compared to maximum temperatures, resulting in an increase in monthly minimum and maximum temperatures across different seasons in the basin. The average temperature rise of ۰.۱۹°C projected for future decades is expected to have implications for water resources in the region. The melting of glaciers due to rising temperatures could lead to water scarcity issues that could affect communities downstream that depend on these water sources. This study highlights the importance of understanding climate change impacts on regions like the Gharaghom basin and implementing strategies to manage water resources in a changing climate context. It is essential to continue researching and monitoring the effects of climate change on glaciers and water resources to inform adaptive strategies and policies that can mitigate potential water scarcity issues. This research focuses on the Gharaghom basin in northeastern Iran, utilizing Whrite's and Porter's methods to map the quaternary equilibrium line altitude (ELA) and reconstruct past and present temperatures using a regression model. An artificial neural network is employed to assess the potential impact of climate change on glaciers in the region. The regression model establishes a relationship between temperature and altitude, revealing a temperature lapse rate of -۰.۴۱°C per hundred meters of increasing altitude. Reconstruction of past temperatures indicates a significant increase of approximately ۱۰.۳۶-۱۰.۵°C in mean annualtemperature during the Pleistocene compared to the current temperature in the basin. According to Whrite's and Porter's methods, the recent ELA has risen to approximately ۲۲۳۶ m and ۲۲۰۰ m a.s.l., respectively, from the Pleistocene levels. Considering the present temperature lapse rate and the highest altitude of ۳۲۷۱m, it is estimated that the maximum Pleistocene ELA depression would be around ۸۰۰m due to a modern temperature increase. Using a neural network projection model, linear temperature growth is projected for the next three decades (۲۰۲۱-۲۰۵۱) in the Gharaghom basin. Trend analysis indicates that minimum temperatures have been more significantly affected by global warming compared to maximum temperatures, resulting in an increase in monthly minimum and maximum temperatures across different seasons in the basin. The average temperature rise of ۰.۱۹°C projected for future decades is expected to have implications for water resources in the region. These findings highlight the importance of understanding climate change impacts on the Gharaghom basin and can inform strategies for managing water resources in a changing climate context. In conclusion, climate change is a global issue that requires urgent action to mitigate its impacts. The Gharaghom basin in northeastern Iran is just one example of a region that is facing the consequences of rising temperatures. The findings of this research underscore the importance of understanding and addressing the effects of climate change on water resources to ensure the sustainability of our planet for future generations.

کلیدواژه ها:

Quaternary equilibrium line altitude ، MRI-ESM۲-۰ model ، reconstruction of the past isotherms ، North Khorasan