بررسی تغییرات پوشش‌گیاهی در کانون‌های داخلی و خارجی ریزگردها با استفاده از تصاویر ماهواره‌ای MODIS (مطالعه موردی: استان کرمانشاه)

Vegetation is one of the most important components of ecosystem, which plays an important role in protecting soil and preventing its rise. So, monitoring and evaluating its changes in planning to control the dust storm is effective. The purpose of this study was to investigate the changes of vegetation in the internal and external dust storm sources of Kermanshah province and dust extension areas. For this purpose, horizontal visibility data were obtained from the meteorological administration of Kermanshah in the statistical period 2005 to 2015. In 2008 and 2009, as well as in the months of May, June and July, due to the most frequent occurrence of days with dust were the basis of study. In the next step, the most important events of dust in the years and months were selected based on two criteria of minimum horizontal visibility and maximum duration of continuity and the MODIS satellite image (MOD02) was obtained for them. The BTD method was used to detect dust storm. Then vegetation changes were evaluated using MOD09 Q1 MODIS and NDVI index in three year intervals and in good, moderate and poor vegetation categories. The results of this study showed that in 2006 the area of good vegetation class in the external and internal dust storm sources was 1.8% and 28.25%, respectively, but in 2015 the area of this class decreased in both external (0.87%) and internal (18.62%). In general, considering the important role of vegetation in soil conservation, it can be taken with the conservation, regeneration and extension of the vegetation, especially in areas where the results of this research have been reduced, have taken an effective step in controlling the dust storm.