An Object-Oriented Approach for Modeling Urban Land-Use Changes

Where to get data for urban planning and management is one issue, but how to manage these data is still a challenging task. This article focuses on the technical issue of managing data. The core data for urban planning are land-use data, which, if updated frequently, raises the issue of structuring, storing, querying, and displaying the data. Modeling, querying, and displaying changes in land-use data have been a challenge for many designers and urban planners. We propose a novel approach to model land-use changes based on object-oriented concepts and a mathematical theory of cell complexes. For object-oriented concepts, the Unified Modeling Language is used. Each land use is considered as an object. This object is an instance of the SpatioTemporalAttributeClass, which is the aggregation of SpatialClass, TemporalClass, and AttributeClass. The AttributeClass is a metaclass of LanduseClass and EvidenceClass. This article focuses on the AttributeClass (land use). The two types of land uses considered here are detailed and general land use. Detailed land use is recorded at the parcel level, while general land use does not require parcel information. Parcel-level land use is indispensable for many operational and strategic planning exercises. An object-relational approach is employed to achieve the model at the logical level. This approach may help alleviate the accessibility problem of land-use data in an urban environment. Through Structured Query Language, it is demonstrated how the spatiotemporal queries can be made. poral queries are briefly introduced in the following section. This is followed by modeling parcel and land-use change, logical schema, and examples of scanning land-use history. Differences between this model and other models, such as the space-time composite or simplicial complex approach introduced by Worboys (1994), are also discussed. The article concludes by pointing out some of the limitations and advantages of the adopted approach. Time series land-use data of Karachi are used for prototyping. Cell Tuple-Based Spatiotemporal Data Model The conceptual schema for the unified cell tuple-based spatiotemporal data model (CTSTDM) is presented using Unified Modeling Language (UML). UML is a conceptual schema language for designing the model. A description of UML can be found online at http://www.uml.org. The parcel-land-use object is an instance of the SpatioTemporalAttributeClass, which is the aggregation of SpatialClass, TemporalClass, and AttributeClass (three components of reality). The time is fused to SpatialClass and AttributeClass. The SpatialClass and TemporalClass are aggregated to form the SpatioTemporalClass, and AttributeClass and TemporalClass are aggregated to form an AttributeTemporalClass. A change in land-use object causes either change in the objects of SpatioTemporalClass, AttributeTemporalClass, or both classes, simultaneously. The conceptual schema for CTSTDM is presented in Figure 1. SpatialClass has one PointClass (subclass). A SpatioTemporalClass is a superclass of three classes (i.e., ZeroTCellClass, OneTCellClass, and TwoTCellClass). The objects of these classes are ZeroTCell (ZTC), OneTCell (OTC), and TwoTCell (TTC), respectively. The object of SpatioTemporalClass can be defined as an (open) n-tcell in a to-