Study on the Distribution Characteristics and Influencing Factors of Rock Glaciers in the Lenglongling Region of the Eastern Qilian Mountains

Abstract

As a typical periglacial landform developed in alpine mountains and shaped by the long-term creep of permafrost, rock glaciers are often regarded as important indicators of regional permafrost distribution and climate change based on their distribution characteristics and long-term changes in movement. With global warming, rock glaciers, as hidden water resource reservoirs in cold regions, have become one of the important stable freshwater supplies for arid mountainous areas. Meanwhile, the movement stability of rock glaciers is essential in the prevention and control of geological hazards, which is critical to engineering safety and ecological protection in cold regions. Therefore, research on the development, distribution, and movement of rock glaciers has tremendous importance for the ecological environment of alpine mountainous areas. In this research, rock glaciers in the Lenglongling area were identified by visual interpretation based on Synthetic Aperture Radar Interferometry and Google Earth optical remote sensing images. Their geomorphic parameters and activity parameters were then statistically calculated. Furthermore, the Pearson correlation coefficient and geographical detector were used to analyze the correlations among geomorphic parameters of rock glaciers and to investigate how environmental factors affect the distribution density of rock glaciers in the study area. Statistical results demonstrate that the study area is home to 413 rock glaciers, which have a combined area of 73.2 km2 and an average area of 0.18 km2. They are mainly developed at an elevation range of 3200–4600 m, with an average slope of 12.57°. According to downslope movement velocity, 92% of the rock glaciers within the research region possess a mean annual displacement below 100 mm/yr, and there are 27 active rock glaciers. Geographical detector analysis identified temperature, land surface temperature, and elevation as the variables with the highest explanatory power for rock glacier distribution. Correlation and variance inflation factor analyses revealed strong interrelationships among these thermal-related variables. All interaction pairs exhibited bivariate enhancement, with the temperature and land surface temperature pair showing the highest q-value.