Suitability evaluation of urban construction land in Pendik district of Istanbul, Turkey

Abstract

Urban land suitability analysis is a complex process that requires geo-physical and environmental information and relevant expertise to analyse and interpret the information. This paper focuses on the integration of geographic information systems (GIS) and multi-criteria decision analysis (MCA) for the assessment of potential suitability of urban development in Pendik district located in eastern Istanbul, Turkey. Various factors, including geo-physical attributes, accessibility, built-up area and infrastructure, vegetation, and green and blue amenities, were used for the land-use suitability assessments. Two different approaches (a deterministic and a fuzzy modelling approach) were utilised to evaluate the suitability of land uses for residential, industrial/commercial and recreational developments. Standardisation of values and unification of scales in map layers were done using the traditional deterministic approach in the first model, whereas fuzzy logic was used in the second model for the same purpose. AHP weighted the sub-criteria in the first model, and the fuzzy AHP method was used in the second model. The map layers were overlaid using the weighted linear combination for both cases using the GIS software. The final stage of the suitability assessment process consisted of a sensitivity analysis of the selected factors and their associated weights. The integration of fuzzy logic, fuzzy AHP and GIS is an advanced methodology and can improve suitability evaluations compared with those of alternatives based on traditional approaches. From our findings, we note that suitable lands for urban development are mainly located in the central and southern parts of the case study area. Our results also highlight how the spatial distribution of suitability classes vary with the selected model utilised for suitability assessment. The methodologies described in the paper can be extended to similar contexts, both locally and internationally.