# Merging Spatio-Temporal Objects and Business Processes: Land Reform Process Case Study
## 2 Geographical Database Modeling Background
### Conceptual Spatio-Temporal Data Modeling Approaches  
Data modeling ensures the transition from the real world to the digital world. Usually, a modeling approach includes a stage of perception of the real world, followed by a sequence of three modeling levels (conceptual, logical, and physical). The conceptual level is a graphical representation of the data within a formal framework that is easily understandable for schematizing the content of information. Entity-Association models (EA) [13], and object-oriented models like UML [14] are the ones most used.  
The GIS community has progressively introduced conceptual models for integrating the spatio-temporal dimensions within these EA and object-oriented approaches. Spatio-temporal conceptual modeling has many advantages: it provides user concepts that enable the implementation of readable and easy-to-understand data schemes, and it is independent of computer implementation. In addition, it favors the exchange of information between partners of different organizations, and it is transformed using a well-defined set of transformation rules into computer languages [5]. Indeed, when designing spatio-temporal conceptual models, some specific requirements should be considered along with usual data modeling requirements. Conceptual spatio-temporal models should allow the representation of geographical objects and events with their 2D and 3D spatial and temporal characteristics and interactions according to different scales and perspectives [10; 15]:  
STUML [16], Perceptory [17], Profiles-UML [18], aand MADS are popular models based on extensions for Entity-Association (EA) and Object-Oriented (OO) approaches to modeling geographical data. MADS integrates basic spatial and temporal types (i.e., point, line, simple area, instant, interval) and homogeneous sets (point set, line set, instants set, etc.) and offers complete orthogonality between the thematic, spatial, and temporal dimensions. These dimensions can be freely assigned to classes, attributes, and associations. This model provides a graphical language and pictograms to support topological and temporal relationships between objects. MADS explicitly supports multiple representations and has a hierarchy of generic spatial and temporal types and intuitive visual notations. MADS has been extended to support spatio-temporal processes [19; 20] and to support 2.5, 2.75, and 3D spatial representations [21]. The spatio-temporal processes (STP) modeling approach provides a complementary approach to MADS with conceptual support for the representation of spatio-temporal processes [20]. Events are defined through processes that transform entities. It proposes a typology of three main classes of basic STPs: (i) evolution of a single entity (basic changes, transformations, and movements); (ii) functional relationships between entities (replacement and diffusion processes); and (iii) evolution of spatial structures affecting several entities [5]. STPs are defined as object types in a database. Thus, actual processes are materialized \"as object instances of the appropriate type\". STPs can be specialized as needed for the users' needs. This offers a clear enumeration and definition of the processes involved in the dynamics of geographic phenomena [5]. MADS was carefully selected as the foundation for our approach due to its numerous studies that have highlighted its exceptional clarity and readability. In comparison to other models, MADS possesses a multitude of advantages specifically tailored to meet the design requirements of spatio-temporal data [10; 21; 22; 23]. Nevertheless, while MADS's STP enhancement showcases intriguing features [20], it fails in ensuring the crucial independence between data and process modeling, thus limiting the model's extensibility and reusability. To overcome this challenge, we have integrated BPMN as a complementary tool to MADS in order to address the management process dimension [21].