Application of Data Envelopment Analysis Method to Study the Dust Phenomenon in Lorestan Province

Abstract

Dust storm is one of the environmental threats in arid and semi-arid regions of the world like Iran which causes serious damages in these areas. Lorestan province is one of the most vulnerable western provinces exposed to dust storm. In this study, climatic parameters includes precipitation, temperature, the maximum wind speed and predominant wind direction were collected from 5 meteorological stations (Khorramabad, Borujerd, Aligudarz, Nurabad and Pol dokhtar) on the basis of monthly and annually scale during 10 years (2001-2010) and thirty dust storm systems were selected as indicator. Then, the correlation between climatic parameters and dust storms was analyzed by Data Envelopment Analysis (DEA) method. The results showed that the maximum and minimum numbers of dusty days in the study area were in 2008 and 2003, respectively. Also, Peak of dust storm frequency was recorded in July which is highly related to temperature in semi-arid climate including Lorestan province. The DEA method along with the window analysis showed that at some of the stations examined, over time the viewing angle was lower with the passage of time and in some other places was more, the viewing angles had not changed in some stations. It was also found that the average temperature index was the most sensitive index. It is concluded that by moving from the western to the eastern parts of Lorestan province by increasing distance from neighbor countries, local dust sources has become more important than foreign sources and dust storm intensity decreased