Mapping and evaluating land suitability using a GIS-based model

• A spatial model was developed for land suitability assessment integrated with GIS.
• The model relies on soil fertility, chemical and physical properties quality indices.
• The model had good agreement with the previous methods.
• The present model had higher suitability index than previous methods.
• The proposed model was found reasonably useful for land suitability assessment.

Wheat is considered the most important crop in Egypt; however, not all of the land in Egypt is equally suitable for growing wheat. The main objective of this study was to develop a spatial model for land suitability assessment for wheat crop integrated with geographic information system (GIS) techniques. Organic matter, N, P, K, Zn, drainage, texture, depth, topography, surface stoniness, hard pan, hydraulic conductivity, water holding capacity, salinity, ESP, CaCO3 and pH were recognized as factors affecting land suitability for wheat crop in the study area. Three thematic indicators were used in assessing land suitability, soil fertility, chemical and physical properties quality indices. The results of the proposed model were compared with the Square root and Storie methods. The results from the proposed model showed that most of the units fall within the highly suitable class and the moderately suitable class which together represent 71.44% of the total area. About 29% of the study area was marginally suitable and unsuitable for wheat crop and those areas correspond to the adverse physical and chemical properties of the soil. The comparison of the results of the three approaches used showed that the present model has a high level of agreement with the Square root method, whereas all land units have the same classes of suitability with the exception of one unit. The present model allows obtaining results that seems to be corresponded with the current conditions in the area.