Morphometric assessment of tectonic activity in "Galal al-Dura" drainage basin, east of Iraq

الملخص EN

"Galal Al-Dura" is a small drainage basin of an area of 1035.4 Km², located at the middle part of the eastern borders of Iraq, south of the town of Mandili.

This basin is a small seasonal stream, locally called as "Galal Al-Dura”.

It is drained in "Hour Al-Shibicha" to its southwest, which is a part of Tigris River basin.

The studied basin is investigated to examine the influence of tectonic activity through analysis of the geomorphic indices computed using Geographic Information System (GIS).

The results of the calculated geomorphic indices indicate that both the of Asymmetry Factor (Af), and Basin Shape (Bs) indices show relatively high tectonic activity, whereas, the Hypsometric curve and the Hypsometric Integral (Hi), valley floor width to height Ratio (Vf), stream length-gradient (Sl), and mountain front sinuosity (Smf) indices, indicate that the old stage of the stream shows less tectonic activity.

This low tectonic activity is characterized by a landscape with very subdued relief associated with low uplift rates, due to the weak sediments type of the alluvial fan that cover large part of the basin.

Furthermore, the relative tectonic activity index (Iat) is found to be 2.33 (within class 3), which suggests a moderate tectonic activity in the basin.

Two hundred and thirty eight structural lineaments, based on GIS aspect spatial analyst tools are drawn manually; their bearings are measured and represented as rose diagrams.