Wind regime and sand transport in the Sistan and Registan regions (Iran/Afghanistan)
Wind regime and sand transport in the Sistan and Registan regions (Iran/Afghanistan)
复制标题
锡斯坦和雷吉斯坦地区的风势和沙粒输送（伊朗/阿富汗）
DOI：
10.1127/zfg_suppl/2019/0543
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
A. Gohardoust
中科院分区：
文献类型：
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作者：
H. Abbasi;C. Opp;Micheal Groll;A. Gohardoust
在干旱环境中，风成沙丘的形成和沙的输沙速率都受风况的控制。伊朗东部的锡斯坦地区和阿富汗西南部的雷吉斯坦地区受到120天风（Sadobist Roozeh风）的强烈影响，该风沿伊朗-阿富汗边境由北向南吹，然后转向东南进入锡斯坦地区，最后继续向东进入阿富汗西南部，形成了雷吉斯坦沙海。由于土库曼斯坦高压和巴基斯坦低压之间的压力梯度，它在炎热的季节吹起。为了确定风况和沙输运，采用Fryberger（1979）方法计算了基于16个气象站长期数据集的风玫瑰、漂移势（DP）、合成漂移方向（RDD）、合成漂移势（RDP）和RDP/DP比值。利用Landsat ETM数据、谷歌地球场景和现场作业（后者仅在伊朗部分）调查了Registan沙丘的分布。利用GIS和地统计学方法叠加沙丘图，绘制了沙流势的空间差异。结果表明：沿伊朗-阿富汗边界，漂移势（DP）自北向南增大，在锡斯坦地区达到最大值，然后在雷吉斯坦沙海逐渐减小；根据DP匹配，确定了最高风能的位置，正是锡斯坦平原北部短暂湖泊的位置，这些湖泊在旱季是强烈的沙尘和沙尘暴的源头。在1999 - 2007年期间，DP的时间趋势呈上升趋势，随后下降到2015年。结果表明：在120 d （Sadobist - Roozeh）风期，锡斯坦和雷吉斯坦地区的风态是单峰的，这也得到了两地区横向、棒状和棒状沙丘优势的支持。
Both, the formation of aeolian dunes and the rate of sand transport in arid environments are controlled by the wind regime. The Sistan region in eastern Iran and the Registan region in Southwestern Afghanistan are strongly influenced by the wind of 120 days (Sadobist Roozeh wind), which is blowing along the Iran-Afghanistan border from North to South, then shifts it’s direction toward the Southeast into the Sistan region and, finally, continues eastward into southwestern Afghanistan, forming the Registan sand seas. It blows during the hot season due to the pressure gradient between the Turkmenistan High and the Pakistan Low. In order to determine the wind regime and the sand transport, wind roses based on long-term datasets from 16 meteorological stations, the Drift Potential (DP), the Resultant Drift Direction (RDD), the Resultant Drift Potential (RDP) and the RDP/DP ratio have been calculated using the Fryberger (1979) method. The distribution of the Registan sand dunes was surveyed by using Landsat ETM data, Google Earth scenes and field operations (the latter only in the Iranian part). The spatial differences of the drift potential were also mapped using GIS and geostatistical methods overlaying the sand dune map. The results show that the drift potential (DP) increases from north to south along the border between Iran and Afghanistan and reaches to highest values in the Sistan region, then decreases gradually in the Registan sand seas. The highest wind energy, based on DP matches, was determined exactly where the ephemeral lakes in the northern part of the Sistan plain are located, which function as a source area of intense dust and sand storms during the dry season. The temporal trend of the DP showed an increase between 1999 and 2007, followed by a decrease until 2015 in Sistan. The results show that the wind regime in the Sistan and Registan regions is unimodal during the wind of 120 days (the Sadobist Roozeh) period, which is also supported by the dominance of transverse, barchanoid and barchans dunes in both regions.