GIS-Based Morphometric Analysis and Hydrological Assessment of the Hor Al-Shuwaicha Drainage Basins, Eastern Iraq

This study presents a comprehensive quantitative morphometric analysis of the five drainage basins of Hor Al-Shuwaicha in eastern Iraq, which cover a total area of 22,245.54 km². Previous morphometric studies have primarily focused on three basins (Torsaq, Shosharin, and Galal Badra), the morphometric characteristics of the entire drainage system insufficiently characterized. A 30 m Digital Elevation Model was processed using Geographic Information System techniques to delineate watershed boundaries and extract the drainage network, followed by the calculation of twenty-one linear, areal, and relief morphometric parameters using standard equations. The seventh-order stream represents the highest stream order. The Sayed Ghazal Basin exhibits the highest basin relief and a drainage intensity of 0.41, suggesting that rugged topography may enhance drainage. In contrast, the lowest drainage intensity (0.38) in the Galal Badra Basin suggests lower drainage response and potential temporary surface-water accumulation, which may contribute to localized flooding in some areas. Drainage density analysis reveals that the Shosharin Basin exhibits the highest drainage density (1.15 km/km²), indicating a potentially greater tendency for rapid surface runoff. Whereas the Mandaly Basin, with the lowest drainage density (1.09 km/km²), indicates relatively higher groundwater recharge potential. Furthermore, drainage texture ranges from very coarse to fine, while the form factor, circularity ratio, and elongation ratio consistently indicate predominantly elongated basin geometry, suggesting a potentially lower tendency for rapid concentration of runoff. These findings provide quantitative morphometric evidence that can support preliminary flood-hazard assessment and groundwater-recharge evaluation.