investigating the relationship between weather and dust storm parameters using data envelopment analysis, case study of lorestan province

Dust storm is one of the environmental threats taken place in arid and semiaridregions like the western part of iran. lorestan was selected as one of the most vulnerablewestern provinces in iran to dust storm. the main aim of this study was to investigate correlation between climatic parameters and dust storm emission into lorestan province during10 years (2001-2010). climatic parameters includes precipitation, temperature, the maximum wind speed and predominant wind direction were collected from 5 meteorological stations (khorramabad, boroujerd, aligudarz, nurabad or delfan, and pol dokhtar) on the basis of monthly and annually and thirty dust storms occurred during 10-year period were investigated. the correlation between climatic parameters and dust storms was analyzed by data envelopment analysis (dea) method. results showed that the maximum and minimum numbers of dusty days in the study area were recorded in 2008 and 2003, respectively. peak of dust storm frequency was recorded in summer (in july) which is highly related to temperature in semiarid climate. the most important source of dust is originated in lorestan province as both parameters of the maximum numbers of dusty days and the minimum precipitation were recorded in summer. the method of the data envelopment analysis along with the window analysis showed that at some of the stations examined, over time the viewing angle has been less and in some other has been more and the viewing angles in some stations were not changed. it was also found that the average temperature index was the most sensitive index among the indices used in this research. it is concluded that by moving from the western to the eastern parts of lorestan province by increasing distance from neighbor countries, local dust sourcesbecome more important than foreign sources and dust storm intensity decreases.