Development of process-based model for dynamic interaction process in spatio-temporal GIS

Abstract

The thesis proposes an extended representation scheme for temporal GIS; Process-based model - a representation scheme for multiple disciplinary spatial processes as well as their interactions in complex real world systems. Global warming, sustainable long-term developments are the most significant topics in science, resource management and policy making all over the world. These problems depend on the interactions among different constituents in natural and cultural systems. Contemporary temporal geographical information system (temporal GIS) represents spatial, temporal and textual information over geographical area; however, higher level knowledge about the behaviour of underlie mechanism of the changes (i.e. spatial processes) are neglected. Process-based model is difference from contemporary models of temporal GIS in its background theory. Spatial system theory (SST) is the backbone theory in the development of Process-based model instead of cartographic principles in current GIS. The theory provides a universal framework for representing, and understanding different disciplinary systems, which possesses spatial and temporal properties. Apart from the theoretical model, Process-based model adopts Voronoi spatial model to represent spatial and temporal interactions among spatial processes instead of field-based and object-based models, which are commonly used in current GIS. Process-based model consists of three major components to represent spatial, temporal, hierarchical and dynamical properties of spatial processes. A Process-based spatio-temporal data model is developed to study behaviour of spatial process though the mutual interactions between spatial structures (i.e. spatial objects and their spatial relations) and spatial movements (i.e. change). The mutual interactions are analysed and visualised as spatial structure initiates a spatial movement and; meanwhile, spatial movement modifies a spatial structure. Process-based spatio-temporal data model is further extended to handle hierarchical structure of spatial processes. According to SST, spatial hierarchical structure illustrates not only different levels of interacting spatial processes but also the status of complex systems. Process-based spatio-temporal model maintains hierarchy of space, spatial objects and time of spatial processes; moreover, the model allows changes propagation across the different levels. Dynamic modelling of complex system is accomplished by extending Cellular Automata model (CA). CA is originally proposed to model dynamic system with discrete time and space. However, the model operates with regular array of grid only. Voronoi-based CA is developed so that CA can be applied to dynamically model the spatial and temporal interactions among spatial objects with irregular sizes and shapes. Consequently, global complex structure of spatial objects can be generated though local rules of transition. Rule of transition is IF-THEN like clauses which describes local spatial and temporal dynamical interactions among spatial objects. Handling complexity is the most critical requirement in order to achieve long-term success in contemporary planning and scientific problems. This work presents an integrated approach to handle complex spatial, temporal, hierarchical and dynamical problems in the complex real world. GIS (and temporal GIS) will no longer be an integrative computer tool. It is an integrated science that is about the knowledge and technology in spatio-temporal data handling and is a sub-topic in various fields of science. This is about tune to consider the state-of-the-art scientific approaches employed (i.e. system theory) and integrate with GIS. This work is a step towards decision/exploratory-oriented GIS from transitional data-oriented GIS.