Investigating the influence of permafrost on springs water temperature in the Southern Carpathians: A comparative analysis of different source types

The hydrology of rock glaciers is a complex and poorly understood field, marked by uncertainties in water flow dynamics and the uneven distribution of the frozen substrate. One effective method for identifying permafrost - particularly in marginal permafrost regions like the Southern Carpathians - is measuring the temperature of mountain springs at the end of summer. Once seasonal snow has melted, permafrost becomes the primary factor influencing the low temperatures of the springs.

This study examines the spatial and temporal variability of spring water temperatures in the Retezat Mountains to assess the distribution of permafrost and its impact on spring water temperatures. In mid-August 2024, water temperatures were recorded at 62 springs using a Testo 110 instrument with a resolution of 0.1⁰ C resolution. The springs, situated at elevations between 1770 and 2230 meters and were categorized into four groups: (1) springs emerging from rock glaciers, (2) springs from scree slopes and talus slopes, (3) springs from areas with slopes covered with meadows and (4) springs from cirque or valley floors.

Additionally, continuous temperature monitoring was implemented for six springs originating from rock glaciers, using dataloggers, with data collection starting in the summer of 2021. Due to their greater resilience to climate change compared to glaciers, rock glaciers are expected to play an increasingly significant hydrological role in the face of ongoing climate change, acting as vital long-term water reservoirs thanks to their thick insulating debris cover.