The effective factors in soil formation include parent material, climate, topography, time and living organisms. The changes of these soil formation factors cause different physical and chemical properties in the soil. The purpose of this research was to investigate the
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The effective factors in soil formation include parent material, climate, topography, time and living organisms. The changes of these soil formation factors cause different physical and chemical properties in the soil. The purpose of this research was to investigate the relationship between soil-forming factors and soil physic-chemical properties. For this purpose, in four watersheds of Qazvin province, a map of working units was first prepared with field visits with the help of geographic information system at a scale of 1:25000. Then, 101 soil samples were collected and EC, pH, organic matter percentage, sand fraction, silt proportion, and clay percentages were measured. The relationship between soil formation factors and properties was investigated using linear multivariate regression in three methods of Enter, Forward, and Stepwise. To investigate parent materials from the sensitivity factor to the erosion of rocks, for living organisms, the percentage of organic matter through laboratory analysis, for topography from the two factors of slope and height and from the geological era to investigate time and for the climate factor from two Rain and temperature factors were used. The accuracy of these models was validated using two statistics of explanation coefficient and mean squared error. The results demonstrated that the highest R2 value of 0.78 with an RMSE of 0.56 was associated with the relationship between pH and soil-forming factors (regression by the Enter method). There was less than a 50% correlation between silt, clay, and electrical conductivity with soil-forming factors. According to the models obtained in this research, it was found that it is possible to prepare maps of soil physic-chemical properties with the help of soil formation factor maps in different regions by using more extensive modeling.
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