Open Geosci. 2018; 10:782–796 Research Article Open Access Yuwei Cao, Yi Huang, Jing Chen, and YeHua Sheng* Geographic Process Modeling Based on Geographic Ontology https://doi.org/10.1515/geo-2018-0061 Received April 10, 2018; accepted September 25, 2018 1 Introduction Abstract: Considerable attention has been paid to geo- Everything in the physical world is a process [1]. GIS (geo- graphic process-based studies in geographic information graphic information system) technology is currently tran- science research. Finding appropriate methods to express sitioning from a traditional emphasis on the expression geographic processes is challenging, and working to re- of geographical information to a focus on the process of veal the dynamic evolution and underlying mechanisms changes in information [2]. The modeling of geographic behind these processes is worthwhile. This research pro- processes is the basis for analyzing spatial-temporal phe- poses a process-centric ontology model that describes nomena and extracting related high-level knowledge. The the geographical environment from three perspectives, expression and analysis of geographic processes has be- namely, geographic scenes, geographic processes and ge- come the focus of GIS research. Geographic processes are ographic elements. These three aspects are combined to used to describe how geographic elements evolve and the represent the dynamic changes of geographic phenom- interactions between these elements [3]. The expression ena. This research proposes a framework and constructs and analysis of geographic processes should not only in- ten sub-ontologies. These sub-ontologies include the El- clude basic geographical information, such as location ement ontology, Scene ontology, and Process ontology. A (where), time (when) and geographic elements (what), soil erosion process is then selected to demonstrate the ap- but also elaborate on the evolution of geographic ele- plicability of this framework. The entire process is divided ments during geographic processes (how), the process of into three sub-processes (detachment, transport and de- this evolution (why) and deeper spatial-temporal seman- position), and each sub-process is described by identifying tic problems [4]. Expressing the evolution of geographic when and where the process occurred, the elements and processes expresses how geographic elements and geo- their reactions, and the changes in the geographic scene. graphic scenes change through time and space during geo- Different relationships among elements, scenes and pro- graphic processes. The interaction among geographic ele- cesses are defined to explain how and why soil erosion ments reflects the internal mechanisms of geographic pro- occurred. This proposed approach can reveal the underly- cesses and answers the important question of why geo- ing mechanisms of geographic scenes, can be used to ex- graphic processes occur. plore the occurrence and causes of geographic processes The modeling and expression of geographic processes and support the complex representation of geographic el- can be constructed as a modeling framework based on ge- ements. ographic elements that describe changes in geographic el- ements at specific times and locations, depict the states Keywords: Geographic Process Modeling; Geographic On- of geographic elements, and actualize local dynamic ex- tology; Geographic Scene; Soil Erosion Modeling pression. However, the geographic element-centric mod- Yuwei Cao, Yi Huang: Key Laboratory of Virtual Geographic En- vironment (Nanjing Normal University), Ministry of Education, *Corresponding Author: YeHua Sheng: Key Laboratory of Virtual Nanjing, 210023, China Geographic Environment (Nanjing Normal University), Ministry of State Key Laboratory Cultivation Base of Geographical Environment Education, Nanjing, 210023, China Evolution (Jiangsu Province), Nanjing, 210023, China State Key Laboratory Cultivation Base of Geographical Environment Jiangsu Center for Collaborative Innovation in Geographical Infor- Evolution (Jiangsu Province), Nanjing, 210023, China mation Resource Development and Application, Nanjing, 210023, Jiangsu Center for Collaborative Innovation in Geographical Infor- China mation Resource Development and Application, Nanjing, 210023, Jing Chen: Department of Art and Design, Nanjing Audit University China Jin Shen College, Nan Jing ,China E-mail: [email protected]; Tel.: +86-137-7060-0707 Open Access. © 2018 Yuwei Cao et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution- NonCommercial-NoDerivs 4.0 License. Geographic Process Modeling Based on Geographic Ontology Ë 783 eling method lacks the expression of complex spatial- graphic ontology is increasingly important. The National temporal relations and semantic relations among geo- Institute of Electrical and Electronics Engineers (IEEE) es- graphic elements [5, 6]. This method can only partially an- tablished a standard upper ontology working group to swer the questions when, where and what and cannot ex- develop Suggested Upper Merged Ontology (SUMO) [17]. press how geographic elements evolve at a particular time. The U.S. Department of Defense collected the "2002 CIA’s This method also cannot reveal the mechanisms under- basic national conditions"—information to develop a set lying geographic phenomena or internal geographic pro- of traffic domain ontologies [18]. Environment Ontology cesses, nor can it answer the questions how and why. Re- (ENVO) consists of classes (terms) that refer to key envi- searchers recommend this modeling method based on ge- ronment types that may be used to facilitate the retrieval ographic events [7, 8]. This method can be used to describe and integration of a broad range of biological and geo- the evolution of geographic elements, express these pro- logical data [19]. To promote interoperability with estab- cesses through a chain of events, employ events as his- lished geographic resources, many of ENVO’s geographic torical snapshots of objects, emphasize the importance of feature classes have synonyms that reference terms in geo- events, and describe the what and where questions regard- graphic resources, such as the USGS vocabularies, Alexan- ing geographic elements. However, the event-centric mod- dria Digital Library’s [20], the GeoNames geographical eling method emphasizes the results of these events and database’s feature classes, and the earthrealm ontologies focuses on the state of a geographic element at a certain of Semantic Web for Earth and Environmental Terminol- point in time but cannot explore how and why these events ogy (SWEET)[21]. SWEET ontologies are noteworthy be- occur and lacks expression of the interaction mechanisms cause SWEET is the largest geoscience data and terminol- of geographic elements. Thus, Xue [9] and Xie [10] have ogy research project and is supported by NASA [21]. SWEET proposed a process-centric geographic modeling method focuses on the expression of common concepts in the field to express the internal mechanisms of events and estab- of geographical information and disregards the most im- lish relationships, such as process-event-elements. This portant time and spatial relationships in geography, which method also describes the relations among events and ele- hinder the expression of the evolution and interaction of ments of the geographic process. In addition, this method geographic elements. The classification of geographic pro- expresses the evolution of the spatial relationships of geo- cesses is detailed. However, these classifications are not graphic elements during geographic processes [7, 11]. related to other ontologies; thus, the expression of the re- Ontology is a conceptual, formal, explicit, and shared lation among geographic fields, life entities, non-living en- specification [12]. It is a formal description of the concep- tities, time and space in the process of ontology is difficult. tual model, whereas unified modeling language (UML) is Geographic ontology provides a possible method a graphical representation of the object oriented model; of clearly expressing geographic processes. Using geo- both are embodiments of information. The difference is graphic ontology was proposed as the basic tool to ex- that ontology can express more information that is un- press concepts such as geographic processes, geographic derstandable to both humans and computers. Ontology events, and geographic phenomena [6, 22, 23]. The re- is the precise definition of the concept of knowledge and search on geographic ontology previously primarily fo- the relationship among concepts. Ontology can clearly cused on ontological theory [17, 24, 25], knowledge engi- express concepts and implied knowledge and aid in the neering [26–28], information integration [29–32] and in- formation of a knowledge network by mapping different formation retrieval [33, 34]. For the expression of geo- concepts and the extension and association of concepts. graphic processes, Grenon and Smith[6] proposed SNAP This approach objectively represents the conceptual struc- to describe an instantaneous process and SPAN ontology ture of the geographic world [13]. This approach helps to describe a continuous process. To characterize different one understand specialized knowledge and allows peo- types of geographic processes, the model divides the geo- ple to reach a common understanding along with a com- graphic process into an instantaneous process and a con- monly accepted recognition and definition of a concept.