Spatial analysis of spring dust storms hazard in Iran

In this research, monthly data on the frequency of dust storms of 44 synoptic stations of Iran during a 50-year period from 1968 to 2017 and methods of Ward's hierarchical cluster analysis, linear regression, Mann-Kendall test, and kriging geostatistic were used. After calculating the frequency of occurrence of dust storms and its related statistical characteristics, suitable probability distribution function was fitted with dust storm data and then, using cluster analysis, the classification of different regions of the country into homogeneous groups was done and by using the kriging method, the zoning of dust storms was performed. After examining the descriptive statistics of spring dust storms in Iran, it was found that the probability distribution of dust storm data occurrence is proportional to the probability distribution of the normal 3-parameter log normal. According to the results of cluster analysis, different regions of the country were clustered into five homogeneous regions comprising of (1) southeast regions, (2) southern and central regions, (3) western regions, (4) eastern and middle regions, and (5) the northern regions. In investigating the trend of time variations of dust storms, it was revealed that the frequency time series of dust storms in Iran had an increasing trend and these results were confirmed by Mann-Kendall statistics. After zoning, it was found that the main focus of this phenomenon was concentrated in the southeast and southern parts of the country.