Modeling of Dust Day event in Sistan basin (Southeastern of Iran)

Recent changes of environment, causes rising of the dust event and became a threat for the environment and civilians, so, assessing that has a high necessity. In this research we attempt to model the mentioned phenomena in the Sistanbasin located in southeastern of Iran with a wide region of arid and semi-arid. In this regard, climatic variables used for modeling are: wind, vapor pressure and Effective Drought Index in daily time-scale. The Wind Speed Threshold applied as the first criteria ondition, saturation vapor pressure as a second and EDI categories as a third. Afterward, the results compare with the criteria in hierarchy pattern of model. In order to examine the model, years of 1971-2000 supplied for calibration and 2001-2009supplied for validation period. Calibration results shows a high accuracy and acceptable error as R2 = 0.856 and RMSE = .7 (day). On the other hand, validation results confirm the model calibration with R2 = 0.881 and RMSE = 3.7 (day). The behavior of model in rising and falling with a high time correlation shows the model efficiency. According to the results, it can conclude that, the model is able to determine the occurrence probability of dust event in exact time and it is very useful for forecasting.Keywords: Dust event; wind, vapor pressure; effective drought index; wind speed threshold; Sistan basin

کلیدواژه ها:

Dust event ، wind ، vapor pressure ، effective drought index ، wind speed threshold ، Sistan basin