Mohammad Rostamtabar; Sadat Feiznia; ziaodin Shoaii
Abstract
More accurate understanding of rock formations and sedimentary units sensitive to erosion willenable us to present appropriate and timely methods in order to prevent accelerated erosion. In thisstudy, through predefined sampling from main and minor channels and granulometric analysisusing index sieves, ...
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More accurate understanding of rock formations and sedimentary units sensitive to erosion willenable us to present appropriate and timely methods in order to prevent accelerated erosion. In thisstudy, through predefined sampling from main and minor channels and granulometric analysisusing index sieves, mineralogical investigation has been performed qualitatively and quantitativelyby binoculars in laboratory. After that, sedimentation potential has been calculated by usingpractical formulas. Then, sedimentation potential of each sedimentary unit has been estimated fromaverage results of sedimentary sample and with this method, sedimentation potential of ShafaroodWatershed has been obtained from average results of five sub basins. An equation has beencalculated for each sub basin and by this, an equation for whole watershed was presented. In thisequation, the Y which refers to the amount of delivered sediments has been placed in one side androck unit coefficients on the other side. The coefficient of each rock unit has a rule in sedimentproduction. These coefficients are dimensionless and demonstrate rock unit sensitivity to erosion.The bigger this value, the more sensitive that rock unit is to erosion. In this way, the map ofsensitivity to erosion for each sub basin has been prepared by using (ARC GIS) software.According to average sedimentation potential of Shafarood Watershed, marl units (Pgf), silty sandyshale (Jsh) and sandy limestone (Kusl), have respectively the highest sensitivity and limestone units(P), andesite - basalt (Pev) and tuffy shale (V) have the least sensitivity to the erosion.
