Effects of Land Use Change on Soil Wind Erodibility in the Horul Azim Marshland

Abstract

In the past, the Hur al-Azim marshland served as a natural absorber of dust particles owing to its water content. However, due to a reduction in its expanse, it has transformed into a notable source of dust production in the region. The mitigation of wind erosion necessitates a comprehensive understanding of the quantity and influential factors of wind erodibility. This research endeavors to assess the impact of the drying process of the Hur al-Azim marshland on the wind erodibility. A total of 44 sampling points were strategically chosen along a perpendicular transect to the marshland, specifically in its desiccated segments, with intervals of approximately 5 km. The evaluation of wind erodibility and wind threshold velocity was carried out through a portable wind tunnel, while pertinent soil physical and chemical characteristics were analyzed in the laboratory. The diverse land uses, encompassing Oil Exploitation Lands (OEL), Marshland Fringe Lands (MFL), Marshland Neighboring Lands (MNL), cultivated lands, and virgin lands, were scrutinized for the variability in soil physical and chemical parameters. Subsequently, the influence of these characteristics on wind erodibility and wind threshold velocity was investigated. Leveraging the R software and employing the multiple linear regression (MLR) method, a robust combination of independent variables (physical and chemical properties) was determined and utilized to predict the dependent variables (wind threshold velocity and wind erodibility). Cultivated land exhibited the highest wind erodibility, coupled with the lowest organic matter content. The maximum wind threshold velocity was observed in virgin land, MFL, and MNL land uses, reaching 12 m/s, while the minimum was recorded in MFL and cultivated land at 2.4 m/s, attributed to the soil moisture exceeding 24.83% in MNL and MFL land uses. The findings indicate a linear and inverse correlation between wind erodibility and soil moisture (R² = 0.42). Notably, the correlation coefficients between soil parameters and erodibility are considerably low, suggesting a lack of statistically significant relationships. The desiccation of the Hur al-Azim marshland emerges as the predominant factor influencing wind erodibility in this region. Consequently, augmenting soil moisture and reinstating marshland water proves instrumental in mitigating wind erodibility.