analyzing andtracing ofdusthazard inrecentyears inkermanshah province

different patterns of pressure systems together with local factors, leads in generation, risingand spread of dust in west of iran. in this study, to investigate the factors causing the occurrence of dust inkermanshah province, 132 cases of dust phenomena (code: 06) were selected and analyzed using kermanshahsynoptic station data for the spring and summer seasons in a period of 5 years (2005-2009). the factoranalysis had been implemented and days with higher correlation coefficient extracted, then clustering operationwas performed on the data. 4 dust emission patterns were identified and from each pattern, a certain patternwas selected as a representative day. using grads and ncep data, maps of geopotential heights, wind speedand vorticity advection were produced and analyzed. to identify the source of dust generation, tracing andsimulating the path of dust, hysplit model lagrangian approach of backward trajectory was used. generallyexistence of low pressure cells in the central and southern regions of iran can lead to the convergence and airintake at near ground levels and strong positive vorticity, which result in cyclonic movements in westernregions of iran including kermanshah. these results in the transfer of dust from the dry desert areas of iraq andhigh speed winds in the lower levels of dust particles in the region has accelerated the transfer rate. based onthe hysplit outputs, major sources of dust generation, were arid zones of southern turkey, iraq deserts,syria, north east of saudi arabia and kuwait.