Morphological change and migration of revegetated dunes in the Ketu Sandy Land of the Qinghai Lake,China  

作　　者：WU Wangyang ZHANG Dengshan TIAN Lihui SHEN Tingting GAO Bin YANG Dehui 

机构地区：[1]School of Earth Sciences,East China University of Technology,Nanchang 330013,China [2]State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining 810016,China

出　　处：《Journal of Arid Land》2023年第7期827-841,共15页干旱区科学（英文版）

基　　金：funded by the Jiangxi Provincial Natural Science Foundation (20202BABL213028);the Open Project of the State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, China (2022-KF-07);the Doctoral Scientific Research Foundation of East China University of Technology (2019052, 2019045)。

摘　　要：Alpine revegetated dunes have been barely researched in terms of morphological change and migration within its regional aeolian environments. To reveal the sand-fixing and land-reforming mechanisms of artificial vegetation, we observed the morphology and migration of four dunes with four revegetated types(Hippophae rhamnoides Linn., Salix cheilophila Schneid., Populus simonii Carr., and Artemisia desertorum Spreng.) using unpiloted aerial vehicle images and GPS(global positioning system) mapping in 2009 and 2018. Spatial analysis of GIS(geographic information system) revealed that the revegetated dunes exhibited a steady progression from barchan dune shapes to dome or ribbons shapes mainly through knap planation, wing amplification, and slope symmetrization. Generally, conditions of northern aspects, smaller slope degree, and larger altitude of unvegetated dunes would suffer more serious wind erosion. The southward movement of dune wings with a migration speed of 2.0–5.0 m/a and the alternating motion of sand ridges in eastwestern directions led greater stability in revegetated dunes. The moving distances of revegetated dunes remarkably changed in patterns of quadratic or linear function with depositional depth. Compared with unvegetated dunes, the near-surface wind velocity of revegetated dunes decreased by 20%–30%, which led to heavy accumulation in low-flat dunes and erosion in high-steep dunes, but all vegetation species produced obvious sand-fixing benefits(100%–450% and 3%–140% in the lower and higher dune scales of revegetated dunes, respectively) with decreasing sand transport rates and increasing coverages. In practice, the four vegetation species effectively anchored mobile dunes by adapting to regional aeolian environment. However, future revegetation efforts should consider optimizing dune morphology by utilizing H. rhamnoides as a pioneer plant, S. cheilophila and P.microphylla in windward and northward dune positions, and A. desertorum in a sand accumulative southward position. Also, we shou

关 键 词：artificial vegetation dune morphology MIGRATION aeolian factor species difference 

分 类 号：X171.4[环境科学与工程—环境科学] P931.3[天文地球—自然地理学] Q948[生物学—植物学]