Investigation of dust storms effect on vegetation cover of Shadegan wetland

Investigating and understanding the impact of dust storms on wetland vegetation changes can lead to useful information for their optimal management. In this study, the wind rose and hurricane rose diagrams of the research area were prepared using wind statistics of Ahvaz meteorological stations. Changes in vegetation cover of Shadegan wetland were determined using classified soil-adjusted vegetation index (SAVI) maps of MODIS satellite images from 2002 to 2011 and correlations of vegetation changes were analyzed using dust storms data of Ahvaz meteorological station. The results showed that the major winds in the region flow from northwest to west and have the ability to create dust. The trend of changes of the number of stormy days, the concentration of dust and vegetation, were proportional to each other. The correlation between the number of dust days per year and the percentage of area with good vegetation cover showed relatively good relationship (the coefficient of determination was 0.47). The correlation between total dust concentration and vegetation cover, with a coefficient of determination of 0.58, indicated the high effect of dust on vegetation cover in the study area. The trend of changes in dust concentration with vegetation index was decreasing in one, two, three, four, and five months before image date. The relationship between dust concentration one month ago and vegetation percentage (SAVI index) with a coefficient of 0.99 showed the highest correlation. The negative and significant effect of dust storms on vegetation doubles the importance of the issue in Shadegan International Wetland, and on the other hand, the use of satellite images can provide accurate information with less cost and time to manage vegetation water and soil resources for managers.