Recent changes in physical properties of the land surface and their effects on dust events in different climatic regions of Iran

Abstract

The physical characteristics of the Earth’s surface play an important role in controlling the velocity of the wind erosion threshold. Therefore, to reduce the risks of dust storms, it is necessary to determine the impact of changes in this characteristic on wind erosion events in different regions. In this regard, this study was carried out to examine the effects of soil moisture (SM), land surface temperature (LST), and vegetation cover (VC) on wind erosion phenomenon using a combination of satellite data and terrestrial observations from 2010 to 2018. In this work, the dust storm index (DSI) was selected to monitor the wind erosion across the country. The multivariate regression method was utilized to explore the effect of alterations in these parameters on changes in soil erosion at both local and regional scales in Iran. In the local scale, regression coefficients between LST-DSI, SM-DSI, and VC-DSI were estimated in the range of 0.002 to 0.77, −0.029 to −0.51, and − 0.001 to −0.82, respectively. On the regional scale, alterations in the LST and EVI could show about 40% of changes in the wind erosion activity over arid regions of Iran (R2 = 0.43; P value < 0.05). Our results also exhibited that the relative importance of the vegetation cover was greater than LST and SM in these areas (β2EVI = 0.17 > β2LST = 0.15). In semi-arid regions, 36% of changes in DSI was due to alterations in LST and SM (R2 = 0.36; P value < 0.05). The relative importance of LST was approximately 1.7 times that of SM in this region of Iran (β2LST/β2SM = 1.73). However, it was revealed that changes in the physical properties of the land surface had no significant effect on dust emissions over the temperate and continental regions of Iran (R2 < 0.16; P value > 0.05). These results can be used by planners and managers to develop programs to combat wind erosion and reduce the risks posed by dust storms in arid and semi-arid regions of Iran.