Subjects: Biology >> Ecology submitted time 2023-03-13 Cooperative journals: 《干旱区研究》
Abstract： The understanding of the evolution process of barchan dune and its movement rate is an important prerequisite for wind prevention and sand fixation and ecological construction in Minqin oasis. Based on field measurement and high- resolution remote sensing image analysis, The study discusses the relationship between the morphological parameters of barchan dune and its movement rate in the upwind edge of Minqin oasis. The results show that: (1) The aspect ratio of the dunes remains a constant value of 16 in 16 years. (2) The average annual moving distance of the tall dune is less than 3 m, which is a medium moving speed. The shape of the tall dune is basically unchanged, and the change is obvious only at the baseline, ridge line, and wing Angle of the windward slope. Low dunes move fast, with an average annual distance of more than 10 m, which is an extremely fast-moving speed. (3) The downwind velocity of the dune is inversely proportional to its width, and the proportionality constant is 718.52 m2 ·a-1. In this area, the barchan dune is dominated by fast-moving speed, which is greater than 5 m·a-1, accounting for 52.63%. (4) During the process of sand erosion on the windward slope and deposition on the leeward slope, large dunes maintain stable morphology and move slowly. Small dunes change dramatically and move rapidly, and the dunes tend to shrink in development.
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