Investigation of lithological units susceptibility of erosion using mineralogical characteristics

Soil resource conservation requires management approaches and provides appropriate solutions that can be achieved by knowing nature of rock units and relative importance of main sediment sources. The aim of this study is to determine hole of each lithological unit in sediment generation and to recognize their erosion conditions. For this purpose after sampling the sediment source and sediments of waterways of Kiov-chai Watershed, grading was performed for all samples by dry sieving. Then, 600 micron and 4 mm sieves were selected as indicators and by choosing 100 grains of sediment from each sample, mineralogical analysis was performed using a pair of binocular and considering mineral and rock fragments the results were compared with and adapted to the lithological units and the share percentage of each stone, was determined by counting the number of minerals and rock fragments. The results showed, Qvl lithological unit has the highest share in sediment yield with a 45.51 percent and has the very severe erosion status with total erosion index score with a 1053.14 which can be justified completely due to extensive degradation and its spread on both sides of the main river. After Qvl lithological unit, Qds2 and Qvb lithological units have the highest share in sediment yield with a 30.87 and 10.54 percent, respectively and Qtasllithological unit has the lowest share in sediment yield with a 45.51 percent.