مقايسه روش زمين شناسي و روش ژيومورفولوژي براي مطالعات خاكشناسي در منابع طبيعي

A Comparison of Geology and Geomorphology Methods for Soil Science Studies in Natural Resources

Soil science studies, base of most natural resources research, are of high expenses due to the large number of profiles needed for evaluation of soil properties. So we need methods through which one can evaluate soil characteristics while, using a low number of profiles. Tow common soil studying methods, geology and geomorphology, were compared in Hassanjoon sub_catchment of Taleghan drainage basin, located in 50degree 37ʹ to 50degree 50ʹ longitude and 36degree 7ʹ to 36degree20ʹ latitude with high geological as well as geomorphological variations. Initially a map of geomorphological and geological units was prepared through photogeology and field checks using geomorphologic information system of 1:20000 scale. Then were made 60 profiles from which soil samples were taken for physical as well as chemical analysis in which pH, EC, %OM , % CaCo3, %silt , %sand and %clay were determined. Results indicate that geological units are not homogenous so that the profiles located at facies in each lithologic unit are of high significant difference (except for pH). So it is necessary to separate facies in each lithological unit. The profiles made in different slopes in each facies were not of a significant difference, and on the other hand, using a high number of profiles didnʹt add to the accuracy of the study. So geomorphological method (separating facies in lithologhic units) is a more efficient one than geological method for soil studies in natural resources, in climates similar to the one in this study.