التقييم المكاني والزماني لفئات مخاطر تآكل التربة خلال الأشهر الأكثر برودة وحرارة (ينايرويوليو) في محافظة واسط، العراق (1979-2022)

Abstract

Soil erosion is one of the most serious forms of land degradation, particularly in arid and semi-arid environments where harsh climatic conditions and human pressures exacerbate soil fragility. This study aimed to assess the spatial and temporal variability of soil erosion risk categories in Wasit Governorate, eastern Iraq, focusing on the coldest and warmest months of the year (January and July) during the period 1979–2022. A GIS-based numerical modeling approach was used, employing multi-time Landsat satellite imagery (Landsat 5, 7, and 8), supported by climatological data and spatial analysis techniques within the ArcGIS environment. Soil erosion risk was classified into three categories: low (no erosion risk), medium, and high. The results reveal significant seasonal and temporal variability in soil erosion risk in the study area. During January, the low and medium erosion risk categories generally expanded due to increased soil moisture and vegetation cover, although a gradual decrease in stable soil areas has been observed over recent decades. In contrast, July saw a significant expansion in the medium and high erosion risk categories, driven by extreme temperatures, soil aridity, reduced vegetation cover, and intensified wind erosion. Long-term analysis indicates a clear shift from low to medium and high erosion risk, particularly during the summer months, reflecting the combined impacts of climate variability, land-use changes, and declining environmental resilience. Spatially, high erosion risk areas were concentrated mainly in the eastern, southern, and central parts of Wasit Governorate, while relatively stable areas remained confined to irrigated lands and areas adjacent to the Tigris River. The generated soil erosion risk maps provide essential spatial evidence for identifying priority areas for soil conservation and sustainable land management. This study contributes to improved regional environmental planning and supports decision-makers in developing adaptive strategies to mitigate soil erosion risks under ongoing climate change.