Investigation of Sand Drift Potential (Case Study: Yazd – Ardakan Plain)

Erosion by wind is one of the most important factors in desert environment. Prevailing winds can shift sand dunes and affect their accumulation. Also, wind regime determines the direction of sand dune mobility. The aim of this research was to investigate sand drift potential using sand movement models. For this research, wind data between ۱۹۸۶ and ۲۰۰۵ from the meteorological station of Yazd were acquired to examine sand drift potential (DP), and erosive storm winds through different methods. The sand drift potential values show that the resultant drift direction (RDD) is from southwest-west towards northeast-east. The unidirectional index value is ۰.۴۷. The Yazd – Ardakan plain is under the influence of a low energy wind regime (DP< ۲۰۰ VU). The DP index should be considered for planning and development projects and conservation work. Calculations show that under a low energy wind regime, the amount of sand drift flow is ۱۵.۷۴ m۳ m-۱ year-۱. The angular direction of RDD is ۷۷°, measured clockwise from the geographical north. The trend of sand movement is observed following a clockwise pattern. With regard to the monthly sand rose, it is seen that the resultant drift potential is low in September and October (۱.۹۱-۲.۱) while the highest resultant drift potential occurs in May. The results obtained from the analysis of wind rose data indicated that the direction of prevailing winds in the Yazd basin is generally from west to north-west, and the storm winds have been generally directed northwest, and the frequency of winds of a velocity less than ۶ m s-۱ (threshold velocity) is ۹۳.۷۹% as observed from Yazd meteorological station.

کلیدواژه ها:

Fryberger method ، Sand dunes ، Sand rose ، Storm rose ، Wind regimes ، Wind Rose