Z. Rashidi Koochi; Isa Esfandiarpour Borujeni; A. Abbaspoor
Abstract
Geopedology which is a systematic approach to analyze the influence of the geomorphic levels on soil mapping, makes it possible to generalize the soil survey results in one geomorphic unit to the other similar units of a studied area that resulted in reducing the time and costs of soil survey. The main ...
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Geopedology which is a systematic approach to analyze the influence of the geomorphic levels on soil mapping, makes it possible to generalize the soil survey results in one geomorphic unit to the other similar units of a studied area that resulted in reducing the time and costs of soil survey. The main question, in this regard, is to what extent the soil data generalization can be valid? To answer this question the effect of landform's kind on the reliability of the geopedology approach was studied in an area of about 1500 ha on the east of Damavand. For this purpose, the geomorphic units were determined by interpreting the 1:55000 scale air-photos of the study area. In the next step, two similar delineations were selected in the piedmont landscape and two similar ones were selected in the hill-land landscape as well. Then, according to semi-detail soil surveys, some pedons were studiedin each of similar delineations. Through the description and sampling of all of pedons and through physical and chemical analyses on all of the pedons’ master horizons, the pedons were classified up to the family level according to Soil Taxonomy system. The results indicated a significant effect of landform's kind on the results of geopedology approach. Although the kind of map unit for similar landforms was the same; the similarity was lower among the pedons in the hill-land landscape than the piedmont in all levels of Soil Taxonomy system. It was probably due to the more slope variations in the hill-land (compared to piedmont areas), and as a result, a greater spatial variation of the nature of exist soils on this landscape.
Z. Rashidi Koochi; I. Esfandiarpoor Borujeni; A. Abbaspour; A. Kamali; A.A. Naderi
Abstract
Geopedology is a systematic approach to analyze the geomorphic levels for soil mappingwhich organizes natural terrains in a hierarchical order in accordance with their scale. Hereon, the effect of mapping scale and kinds of soil classification system on the reliability of the geopedologic approach was ...
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Geopedology is a systematic approach to analyze the geomorphic levels for soil mappingwhich organizes natural terrains in a hierarchical order in accordance with their scale. Hereon, the effect of mapping scale and kinds of soil classification system on the reliability of the geopedologic approach was investigated. In view of that, after air-photos interpretation (1:55,000 and 1:40,000 scales) of an area (1500 ha) on the east of Damavand, two similar delineations (named A and B) were selected on the geoform map. Then, some pedons were dug in the similargeoforms based on semi-detailed soil surveys. The pedons were classified up to the family level according to Soil Taxonomy and up to the subunit level (including suffix and prefix qualifiers) based on WRB soil classification systems. This was the conducted when description and sampling from all genetic horizons and physical and chemical analyses had been already done. The results showed that mapping scale affected the results of the geopedologic approach significantly, so that relative similarity in all taxonomic levels was lower in 1:40,000 scale than the 1:55,000 scale for all studied pedons. Besides, Soil Taxonomywas more adaptable than WRB in predicting the relative similarity among soils in the same geoforms. On the whole, the geopedologic approach is still not able to estimate and determine the complete variability of soils and define their chaotic nature precisely, and the performance of this approach is limited to semi-detailed surveys and smaller ones.