Investigation of roughness variation using wind shelter angle index in different pediment (Case Study: Khezr Abad - Rostaqh of Yazd Ardakan Plain(

In this study, it has been tried through using wind shelter angle index to consider the changes in roughness of land surface across the piedmont longitudinal transects in Khezr Abad – Rostaqh of Yazd Ardakan Plain. By using roughness pin meter and based on Putter et al. method, the wind shelter angle was measured across 35 cm of longitudinal transects. Data of elevation points was imported to Minitab & Excel software and necessary calculation for relative & cumulative abundance was carried out. Comparison between variance analysis (duken method) of pediments shows significant difference in statistic level of below 1%. Meanwhile the eroded pediment has the highest vegetation cover with wind shelter angle. In eroded pediment as an average 18.11 ± 9.27% of the land surface with an angle more than 12 degree will trap the particles. However in appendage piedmont drops to 8.44±7.73%. The deposit piedmonts in the study area lacks significant roughness and only 0.28±0.58% of the land surface with a 12 degree wind shelter angle is covered which makes the lands of this piedmont more sensitive to wind erosion. The results showed that the indicator for accumulative abundance percentage for the wind shelter angle with more than 12 percent is able to express the roughness in different pediment. The above mentioned indicator is showing that with moving down wards from across the piedmont, while decreasing the roughness of the particles, the wind erosion will be increases.