Developing a model for simulating urban expansion based on the concept of decision risk: A case study in Babol city

Today, the study of the spatial-temporal pattern of urban physical expansion and the identification of the parameters affecting the expansion play a crucial role in urban-related decision-making and long-term planning processes. Consequently, the use of precise and efficient methods to predict the physical expansion of urban areas is of great importance. The objective of present study is to provide a new conceptual model for implementing a simulation model for predicting physical expansion of urban areas based on the degree of risk in multi-criteria spatial decision making. This model has been implemented to predict the physical expansion of Babol city. In the proposed model, the combination of subjective and objective weighting methods has been used globally and locally on the basis of neighboring states to determine the relative importance of mentioned criteria and the Markov model is used for generating the transition rules. In addition to the two parameters of the criteria and the weight of each criterion, the risk-factor parameter is also considered for the mapping of the physical expansion of the city. In order to determine the degree of risk and the optimal weighting method, each of simulated built-up area maps was compared with a real built-up area map. The results obtained for the study area show that the optimum ORness values in local and global strategies for generating suitability map are 0.3 and 0.7, respectively. Moreover, the average overall accuracy for the local and global weighting methods at different levels of risk is 87.6 and 86.8, respectively. This means that the local weighting method is more accurate than the global method for generating the suitability map.