Evaluation of vegetation changes trends in western oak forests and dust phenomenon using satellite and meteorological data integration in Kermanshah Province

In recent years, a considerable part of the western oak forests of the country has been faced with drought and decline. Initial studies have identified one of the factors affecting oak forest dryness as increasing frequency and severity of dust phenomenon. In this study, the MODIS sensors with a resolution of 1 km and 250 m and meteorological data of Kermanshah Province synoptic stations over a 15-years period (2014-2000) was used to investigate the dust phenomenon and the process of forest vegetation changes in the region. Dust intensity was investigated using visibility data and unsupervised image classification method. Also, in this study, the relationship between the occurrence of dust and vegetation changes in oak forests was investigated. Survey of dust events showed that Kermanshah Province had the highest number of dust events in 2008 and 2009, respectively. The highest incidence of severe dust was in 2012. In addition, satellite imagery and spectral indices also showed that the highest reduction of vegetation in dense forests (>50% canopy cover) by 67% and with an overall accuracy of 62% in the south and southeast of Kermanshah Province and at the border of Lorestan and Ilam provinces has happened. Results also showed that the frequency of dust phenomenon is highly correlated (70%) with the phenomenon of oak forest degradation; and dust has the effect of reducing the greenness of oak forests in Kermanshah province.