Abstract
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Introduction

The Maragheh region, located in the tectonically active northwest of Iran, occupies a focal location within the Alpine-Himalayan orogenic belt. The area, delimiting against the southern footslope of Mount Sahand, is marked by the presence of several large-scale rivers like Sufi-Chay, Mordagh-Chay, and Qury-Chay, which have close interactions with active fault systems. As frequent shallow intra-continental earthquakes will keep hitting the area, their impacts are further intensified by increasing population and expanding infrastructure, making reliable tectonic hazard assessment crucial. Geometric parameters such as the Drainage Basin Asymmetry Factor (AF) and the Transverse Topographic Symmetry Factor (T), incorporated into digital elevation models (DEMs) and geographic information systems (GIS), make solid tools to quantify active tectonics and detect displacements of river channels. This study would determine the influence of fault geometry control and stress field orientation on river morphology in the Maragheh region, determine zones of heightened tectonic activity, and explore implications for seismic hazard and water resources planning.

Materials and Methods

The study area includes the southern region of East Azerbaijan Province, between geographic coordinates 45°55'–46°39' E and 37°44'–37°52' N. The regional geology includes Quaternary alluvium, sedimentary rocks, and volcanic rocks such as andesite and dacite, distributed unevenly in the landscape. Ten structural observation sites were sampled during fieldwork, concentrating on orientations and kinematic markers such as slickensides. Two geomorphometric parameters were employed: AF, an asymmetry of drainage basins, and T, an assessment of lateral river migration with respect to basin geometry. These parameters were derived from topographic maps and DEMs using ArcGIS and Global Mapper. In fault activity assessment, Fault Movement Potential (FMP) was calculated under the conditions of tectonic stress and fault geometry, assuming an isotropic, elastic medium. Principal stress directions were calculated using stress inversion techniques, supplemented by structural data and executed in specialized software. The locations of earthquake epicenters for the past 110 years were also examined to verify zones of tectonic activity. River channel offsets were measured systematically and plotted against fault positions in order to ascertain geomorphic responses to tectonic forcing.

Results and Discussion

The outcome indicates that the Maragheh region is tectonically active with large displacements differences of river channels between basins. Of all the basins examined, Qury-Chay, Badamlu, Leylan-Chay, Mordagh-Chay, and Qaleh-Chay experienced most tectonic activity according to high AF and T values. The Qury-Chay basin experienced the greatest channel shift of approximately 4500 meters near Qartar village, indicating activity of the Qartar fault, with an FMP value of 0.8. The fault is discovered to be connected with right-lateral strike-slip movement, as confirmed by patterns of geomorphic index and lithological characteristics. In the Qaleh-Chay basin, the Bokat fault led to a 3000-meter deviation in the channel, while in the Mordagh-Chay basin, the Maragheh fault led to an 800-meter eastward deviation, which is the highest FMP value of 0.9 out of all the researched faults. The AF index allowed for tectonic activity to be classified into high, moderate, and low classes and showed that Qaranaz and Mordagh-Chay basins were two of the most active. Similarly, the T index confirmed these differences, with values 0.4 and greater indicating intense asymmetry and tectonic control. Seismicity information on earthquakes showed concentrations of seismicity in the northwest and southwest quadrants, generally at a high angle to common fault orientations, suggesting a controlling northeast–southwest stress field. Among the faults, the most active was the Bokat fault, based on its large FMP and clustering of seismicity in nearby proximity. The same trend is reflected in other seismically active areas around the world, thus adding to the efficiency of combining geomorphic indices with structural and seismological observations in regional tectonic analysis.

Conclusion

Combined analysis of geomorphic indices, fault mechanics, and historic seismic evidence stresses the over-riding importance of active tectonics in controlling river networks and relief landscape of the Maragheh region. The study efficiently outlined a series of zones of elevated tectonic hazard, particularly those associated with the Qartar, Bokat, and Maragheh faults. The Qartar fault with 4500-meter river offset is an interpreted young and active strike-slip structure, while the Bokat fault exhibited the highest seismic potential. The northeast–southwest direction of stress confirmed through inversion analysis and the distribution of earthquakes is further evidence for ongoing tectonic deformation. Use of AF and T indices and FMP calculations proves to be a valuable approach to seismic hazard estimation and understanding river channel evolution in active tectonic regions. All the findings find immediate application to regional planning, disaster risk management, and sustainable water resources development. In the future, the integration of emerging technologies such as machine learning and 3D geospatial modeling could contribute to the accuracy of tectonic predictions and deepen our understanding of landscape response to faulting.