Spatial interaction modeling

The concept of spatial interaction (SI) encapsulates the domain of human activities that occur between a set of locations embedded within geographical space. Data about such processes are essential for studying a wide spectrum of geographic phenomena that are important to society, such as the accessibility of services, product demand, transportation trends, and demographic dynamics. In particular, SI models seek to explore, explain, and predict aggregate movements or flows that occur across an abstract or physical network, which can be useful on its own, as well as a factor within other regional models. As the number and nature of SI modeling applications have grown, the associated theory and tools have simultaneously evolved to consider more complex spatial relationships, resulting in numerous expansions of the modeling paradigm. In this chapter, some foundations of SI modeling are first laid out before presenting a simple demonstration and then describing several extensions to the core modeling methodology.