Geomorphology and wind regime of barchans in the Lut Desert (Iran)


Milani A. S. , Barkhordari N., Shabani S., Mohammadı A.

ZEITSCHRIFT FUR GEOMORPHOLOGIE, vol.62, no.4, pp.265-290, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 62 Issue: 4
  • Publication Date: 2021
  • Doi Number: 10.1127/zfg/2020/0671
  • Title of Journal : ZEITSCHRIFT FUR GEOMORPHOLOGIE
  • Page Numbers: pp.265-290
  • Keywords: barchan, morphology, aeolian transport, Lut Desert

Abstract

The present research was conducted to determine the morphometry, morphology, and temporal and spatial behavior of individual barchans in the Lut Desert in Iran. This region is one of the driest places in the world and there is a little information about the geomorphology of this region, especially on the barchans. Therefore, herein, a total of 391 individual barchan dunes were selected and their morphometric parameters were compared with respect to the length/width (a/c) ratios (extraordinarily slim to fat barchans), migration rate, direction of movement and influence of wind regime on this landform. The results showed big difference in the morphology, morphometry, and direction and migration rate of barchans between the western and eastern parts of the Lut Desert. The mean migration rate was about 5.17 m/yr in the study area and ranged between 1.1 and 15.35 m/yr. The annual sand drill potential was equal to 1053.9 VU in the western part and 803.6VU in the eastern part of the Lut Desert and it was classified as high-energy wind environment. The NNW direction (620 VU) in the west as well as the SSW direction (100 VU) had a high effect on the movement of barchans. Their direction of movement ranged from northwest to southeast in the western part and from southwest to northeast in the eastern part, which were correlated with the dominant wind directions in these regions. Results of measuring the morphometric parameters of the barchans indicated that mean length, width, height, and maximum length of barchans were equal to 114.5, 179.5, 10.47, and 590.2 m, respectively which are relatively high in comparison with data for other barchans studied in some previous researches in the world. The shape of barchans was classified into slim, nonnal, pudgy, or fat and extraordinarily slim. Most of them were slim (166 barchans, 42.5%) and their distribution differed between the eastern and western parts of the Lut Desert. This can be attributed to local physical situations and wind direction properties.