Analysis of Quantitative Relationship between the Volume of Alluvial Fans and its Relationship Active Tectonic (Case study: Northern Slopes of Alluvial Fans in Bozqush)

Alluvial fans are the most obvious Landforms of fluvial geomorphology which react to changes in tectonic as geomorphic phenomena, and they can be used as a tool for identifying of the tectonic aspect of regions. In this research at first, alluvial fans and their drainage basins located in the northern slopes in Bozqush were extracted in terms of morphometric (area, volume, distribution) and physiographic features (length, area, height) and the relative status of regional tectonic activity was evaluated by using 5 Geomorphic Indicators (α, AF, Bs, Hi, SL).The required parameters consisted of (R, S, H and α) and the other parameters were collected through DEM as well as digital geological maps. The Church Giles methods and Stream power model were used for computing the volume of alluvial fans and the uplift rate of watersheds by using ArcGIS, CAD and MATLAB softwares. Then Correlation was established between the results. Results showed that there is no significant relationship between the catchment area (BA) and the Volume of Alluvial Fans (V); in contrast, a significant and direct relationship was observed with a correlation coefficient 78% between the basin uplift rate and volume of fans. In this regard, by providing  geological maps and location of the faults and its overlap with watershed and alluvial fans, It was found that the formation of large alluvial fans (Bijand, Elahagh) is consistent with upper two reverse and normal strike-slip fault lines (at the outlet of the basin). According to the results, in the current Morph-climatic conditions, tectonic can be considered as a major factor in increase or decrease of the volume of alluvial fans.