Complex spatial systems: Challenges for modellers

Complex spatial systems are defined as those described by many variables, with high levels of interdependence between elements, governed by nonlinear processes and having significant spatial structure. Complexity theorists have sought to build general models, usually on a ‘toy’ basis. In this paper, a model of urban retail structure is used to demonstrate the model building techniques which can be used to build useful and realistic models and a number of mathematical challenges for ongoing research agendas are articulated.