عوامل موثر در شكل گيري و گسترش مخروط افكنه رودخانه رويين در دامنه جنوبي آلاداغ در شمال شرقي ايران

The Influential Factors in Formation and Development of Rouen River Alluvial Fan at the Southern Slope of Alla Dagh Mt ., North Eastern IRAN

The alluvial fan of the Rouen river is one of the biggest alluvial fans of the northern slope of AllaDagh.This alluvial fan formed as a result of different materials erosion into the drainage basin of the Rouen river and laying these materials in the end part of this drainage basin. In forming and developing thi alluvial fan different factors, contributed. These factors can be classified into two groups of external and internal ones. The tectonic role between internal factors is more important than other factors. The different signs and indications on the area ndicate that the area is active in ʹview of tectonic activity. The most important of these are the existence of some active faults, in the region, the deviation profile and reference profile and also the proportion of the width to the depth of the valleys. Affecting the place of the settlement of the alluvial fan, increasing the gradient and, therefore the transportability and amount of sediment in the Rouen river, tectonic activities have contributed to the formation and development of Rouen river alluvial fan . Semi arid climate of the area, as one of the important external factors with an effect on the weathering, stream flow, mass movement and sediment supply in the drainage basin above the Rouen river alluvial fan play their own role in forming and developing this alluvial fan. Hydrology of the area with product and transport and laying sedimental materials also play its own role in forming and developing this alluvial fan. Sensitive and low resisting litology of the area and lack of resisting stones among igneous and metamorphic ones cause acceleration of the weather beaten process. This factor has created conditions for sedimentation increase. In this way, it was effective in forming and developing the alluvial fan of the Rouen river. In addition, human activities in recent years have caused an increase in sedimental load of the Rouen river and sediments also contribute to developing the alluvial fan of the Rouen river, in turn.