首页|Spatio-temporal geomorphological evolution and driving factors of a transgressive dunefield, Qinghai Lake, northeastern Tibetan Plateau
Spatio-temporal geomorphological evolution and driving factors of a transgressive dunefield, Qinghai Lake, northeastern Tibetan Plateau
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NETL
NSTL
Elsevier
This study aims to investigate the evolution and driving factors of the transgressive dunefield on the eastern shore of Qinghai Lake. Image analysis showed that the transgressive dunefield had continuously moved inland from the lakeshore and experienced three major stages between 1970 and 2020: Stage 1 (1970-1996), the dunefield moved slowly (1.40 m/yr); Stage 2 (1996-2013), the dunefield moved rapidly (15.66 m/yr); and Stage 3 (2013-2020), the movement of the dunefield slowed down (7.70 m/yr). The grain size characteristics of the surface sediments indicated that material from the lakeshore was transported inland, undergoing continuous sorting and transformation by the wind. By combining the ERA5-Land dataset and meteorological data to assess the environmental changes, it was found that the correlation between the wind and the changes in dunefield movement speed was weak, as the wind speed progressively weakened throughout the study period. However, the deceleration or acceleration of the dunefield movement often corresponded to the advance or retreat of the shoreline as the lake level rose or fell. This was because the change of the lake level and shoreline indirectly affected the movement speed by regulating the sand supply. Furthermore, the lake level and shoreline change in Qinghai Lake were still primarily controlled by climate change. In general, this study offers a valuable example of transgressive dunefield development along the lakeshore and traces its evolution over the past 50 years by multisource image data. The results suggest that transgressive dune sheets or dune fields can evolve directly from the lakeshore. It also indicates that transgressive dunefields are initiated as a response to the water level fall in cold and arid environments with abundant sand supply.
NETL
NSTL
Elsevier
