The partitioning of space is an essential consideration for the efficient allocation of resources. In the United States and many other countries, this parcelization of sub-regions for political and legislative purposes results in what is referred to as districts. A district is an aggregation of smaller, spatially bound units, along with their statistical properties, into larger spatially-bound units. When a district has the primary purpose of representation, individuals who reside within that district make up a constituency. Redistricting is often required as populations of constituents shift over time or resources that service areas change. Administrative challenges with creating districts have been greatly aided by increasing utilization of GIS. However, with these advances in geospatial methods, political disputes with the way in which districts increasingly snare the process in legal battles often centered on the topic of gerrymandering. This chapter focuses on the redistricting process within the United States and how the aggregation of representative spatial entities presents a mix of political, technical and legal challenges.
Applications of GIS in Political Science encompass analyses and visualizations of populations, states and governments and the interactions between them; and inform decision making in a wide range of venues including policy making, political and electoral behavior and geopolitical interactions broadly. The theoretical antecedents of GIS applications in political science derive from several academic traditions, primarily related to spatial analysis, environmental determinism, and political geography, and are focused on how political and economic factors shape election outcomes. Therefore, the application of GIS in political science is characterized by its emphasis on analyzing and visualizing the spatial dependencies and patterns that underlie political processes. In this way Political Science GIS can be integrated with, expand and inform aspects of other venues of GIS like economics, criminal justice, planning and more.