A Geomorphological Study of Nebkhas in Al-Siniyah Subdistrict, Baiji District

This study investigates the geomorphology of nabkhas in Al-Siniyah Subdistrict (Baiji District) through a comprehensive analysis of their origin and development factors, including geology, topography, climate, vegetation cover, and soil characteristics. Morphometric, granulometric, mineralogical, and chemical analyses were conducted on the sand samples. The results revealed that the nabkhas are mainly concentrated in the northern and western parts of the study area, where vegetation cover plays an essential role in dune stabilization. The elongation of the nabkhas aligns with the prevailing northwesterly winds. Their heights range from approximately 0.3 to 1.8 meters, while their basal diameters vary between 2 and 15 meters. The sand is fine to medium-grained, well-sorted, and predominantly composed of quartz (>80%), with noticeable proportions of gypsum and carbonates, particularly near sabkha environments. The findings confirm that vegetation acts as the primary biotic stabilizer of the nabkhas and that these features serve as reliable field indicators of sand movement directions and active aeolian zones. The study recommends enhancing local vegetation cover and implementing localized windbreaks to reduce sand movement and encroachment, thereby protecting infrastructure and major roads in the region.