Erosion Rate Study of Yardang Landforms Downstream of the Peacock River

Abstract Yardang landforms are significant subjects for research concerning climate change, geomorphological evolution, aeolian sand management, and ecosystem stability. The Lop Nur area, as the origin of the term "Yardang," has seen limited in-depth studies of its Yardang landform development and evolution. This paper integrates field surveys of Yardang landforms downstream of the Peacock River, 14C dating, optical dating, large-scale topographic mapping, and 3D laser scanning to investigate the erosion rates of these landforms. The key findings are as follows: (1) The average erosion rate of the Yardang landforms downstream of the Peacock River since 565 ± 25a BP is between 1.54 and 0.00 cm/year, with 88.32% of the area experiencing rates between 1.37 and 0.55 cm/year; currently, 72% of the area is undergoing erosion at rates ranging from 3.0 to 0.0 cm/year, with 17.30% of that area experiencing rates between 1.2 and 0.6 cm/year, and 38.70% experiencing less than 0.6 cm/year. The current erosion rates are significantly lower than historical averages, with some low-lying areas currently accumulating sediment; (2) A comprehensive research method has been established, based on the developmental patterns of Yardang landforms for historical average erosion rates and on 3D laser scanning for current erosion rates. This method has enabled the determination of both historical average and current erosion rates in the Yardang area downstream of the Peacock River. The establishment of a permanent erosion monitoring network in this area will support long-term tracking and monitoring of Yardang landform development and provide a foundation for research on climate change, geomorphological evolution, aeolian sand management, and ecosystem stability in the region; (3) The study systematically determined the deposition time, exposure time, and erosion time related to Yardang development downstream of the Peacock River, which are 2.8 ± 0.3ka BP, 1900a BP, and 565 ± 25a BP, respectively. These findings are crucial for understanding the evolution of Yardang landforms in the area and will facilitate the advancement of numerical simulations towards long-term geomorphological evolution research. The study provides insights into the timing of Yardang landform development, historical and current erosion rates, and establishes a comprehensive research methodology, which is essential for quantitative research on the formation and development environment of Yardang landforms downstream of the Peacock River.