Application Of fuzzy membership functions and ISOCluster analysis method for soli-landscape map (Case Study: Damavand region, Iran)

Soil and land information is vital for land use planning and infrastructuredevelopment. Maps of soils landscapes are powerful tools to guide sustainableplanning and natural resource management. Fuzzy set theory has been widely usedin soil science for soil classification and mapping, land evaluation, fuzzy soilGeostatistics, soil quality indices. In fuzzy logic-based approaches, soil spatialvariation is expressed as spatial variation of membership in soil classes, which isthen used to produce conventional soil-landscape map and to predict spatialvariation of specific soil properties. The aim of this study is using fuzzymembership functions and ISOCluster analysis method for soli landscape mapswith high accuracy. The following seven topographic variables (elevation, slopegradient, curvature, profile curvature, Plani metric curvature, flow accumulationand topographic wetness index) were used in this study to characterize theenvironment conditions. The proposed methods were tested in Damavand region inthe Northeastern of Tehran. A set of membership functions were constructed torepresent the descriptive knowledge on soil-landscape relationships, then for soil-Landscape map ISOCLUSTER analysis method was used. Using this operator 5soil-landscape units were determined as follows: 1-Valley bottoms, 2-low landplain, 3-moderate hill slope, 4-steep hill slope, 5-mountain.The soil-landscape mapachieved 74% of accuracy. 74% Accuracy is acceptable for an initial soilmapping. This suggests that the membership functions constructed in thisstudy do capture the major pattern of soil-landscape relationships over theregion.