Abstract:

Based on long-term observation of wind speed and direction in different aeolian landform regions， the present study investigated the wind regime and drift potential in the Qaidam Basin. The results indicated that： （1） The trend of the annual average wind velocity， the average sand-driving wind velocity and sand-driving wind frequency of different areas was relatively consistent. As to the yardang landforms， the annual average wind velocity， the average sand-driving wind velocity and sand-driving wind frequency were the highest in long-ridge yardang region near the northwestern edge of Chahansilatu playa， while the linear dune field on the northern margin of Qarhan Salt Lake was the highest among the aeolian depositional landforms. （2） The long-ridge yardangs regions belonged to uni-directional sand-driving winds， while the other yardang regions all belonged to bi-directional sand-driving winds. The sand-driving wind was mainly coming from WNW and NW directions for dunes developed on the piedmont of Qimantagh Mountain. Meanwhile， the sand-driving winds coming from W direction accounted for a higher percentage for linear dune fields. （3） Except for the saw-tooth yardang regions， which had an acute bimodal wind regime， the rest of the yardang areas were under unimodal wind regimes. The long-ridge yardang was developed in a high wind energy environment， and the mesa yardang was in an intermediate wind energy environment. While the rest of the yardang regions were in a low energy environment. The linear dune areas are all in wide unimodal regimes， while the dunefield in front of the Qimantag Mountains is in an obtuse bimodal regime. Except for the linear dunes on the northern of Qarhan Salt Lake， which was in an intermediate wind energy environment， the rest of the dune fields were in a low wind energy environment. （4） The drift potential and resultant drift potential gradually decreased from northwest to southeast across the basin， and the resultant drift direction changes from NNW to WNW due to the influence of topography. The wind direction variability shifts from the low to intermediate wind direction variability from the yardang areas in the northwest to the dry salt lake and dune fields in the south-central.

Key words: wind regime, sand drift potential, dune, yardang, Qaidam Basin