Geographic Information Systems (GIS)
Geospatial technologies provide attractive integrative approaches for meeting current requirements to “do more with less.” New approaches are demanded, supported, and must be implemented quickly for technology, collaboration, workforce development, funding, and other resources. This will include raising awareness of the unique aspects of geolocation from a privacy standpoint. Geospatial technology will increasingly be aligned with and integrated into the broader, ever-evolving technology ecosystem.
The geospatial technology field is at a remarkable point in its evolution, presenting an opportunity to rethink the deployment and use of these resources, and to enhance our ability to solve problems using geographic information while ultimately saving time and money (FGDC, 2013).
- GIS from the early days till today
Bartelme in a journey through GIS, from the early days till today, groups them in two ways: in classic and modern senses (Bartelme, 2012):
- Classical GIS:
- In the classical sense, an information system consists of a database representing the inner core of the system, being managed by a database management system (DBMS), and of an outer shell of tools that can be utilized by the user for manipulating and analysing this data.
- Modern GIS
- But nowadays, we are faced by GIS in a client–server architecture. The traditional setup of a GIS has been modified in several ways, due to the arrival of new technologies and new concepts. The arrival of the Internet, of web-based service approaches, tools, and applications, has greatly influenced and modified the whole IT arena. The second boost has been initiated by mobile technology and the miniaturization of hardware components. Therefore, also the paradigms of GIS have changed, and the architecture of a GIS nowadays is quite different from what it was a few years ago.
- Data are no longer restricted to the user’s primary domain of interest and control, but they can in principle be imported from everywhere, anytime, and to any device (…) We talk about ubiquitous geographic/geospatial information as the universal availability of geographic information as seen on mobile devices such as cell phones, where maps, satellite images, positioning, routing services, and even 3-D simulations are gaining an ever-larger segment of the consumer market.
- Also, in contrast to earlier times when a GIS consisted of a well-balanced combination of hardware, software, and data components, today the borderlines between the functionality of an ordinary Internet browser and GIS functionality is often fuzzy. Likewise, content is displayed that may, via web services such as web map services (WMS), be composed on the fly, coming from different sources but having the appearance of a combined dataset, whereas in many cases the data themselves are not transported but are rather visualized on the fly. The data remain at their various home localities, which is an asset as far as currency and lack of redundancy is concerned.
In Figure 33, according to (Kim & Jang, 2012) is presented the evolution of geographic information from its 1st to 4th generations.
Figure 33 – Evolution of Geographic Information (Kim & Jang, 2012)
Lately, according to (Dangermond, 2012) Cloud GIS arises as the new platform that allows geographic knowledge to be widely shared, enabling widespread access and use of GIS (Figure 34). At the same time, other trends, such as widespread measurement, big data, and ubiquitous computing, are advancing rapidly, including Software as a Service computing, device computing with lightweight and locationally aware applications, as well as supporting scientific exploration and innovation. The convergence of GIS with these trends will enable us to integrate geographic knowledge into everything we do. This new pattern integrates all types of geographic information— maps, data, imagery, social media, crowdsourced information, sensor networks, and much more. Cloud GIS enables ubiquitous access and integrates the traditional work of geospatial professionals with a whole new world of GIS applications.
Figure 34 – Cloud GIS enables pervasive access, integrating traditional GIS with a whole new world of applications (Dangermond, 2012)
In 1999, Chrisman after passing in review several GIS definitions makes a new GIS definition proposal (Chrisman, 1999), - Geographic Information System (GIS) - The organized activity by which people:
- measure aspects of geographic phenomena and processes;
- represent these measurements, usually in the form of a computer database, to emphasize spatial themes, entities, and relationships;
- operate upon these representations to produce more measurements and to discover new relationships by integrating disparate sources; and
- transform these representations to conform to other frameworks of entities and relationships.
Additionally, the parts of a geographic information system according to (Tomlinson, 2011) are presented in Figure 35.
Figure 35 - Parts of a GIS (Tomlinson, 2011)
Presently we cannot talk about GIS without framing it in science, and in what GIScience means. Goodchild highlights two GIScience definitions (Goodchild, 2010):
- the succinct definition adopted by the University Consortium for Geographic Information Science: “The development and use of theories, methods, technology, and data for understanding geographic processes, relationships, and patterns.”, and
- GIScience defined as “The basic research field that seeks to redefine geographic concepts and their use in the context of geographic information systems.” (in a cited report to the National Science Foundation following a 1999 workshop)
According to (Wang, et al., 2013) in the foreseeable future, GIS will likely continue to play essential roles in many fields (e.g., ecology, emergency management, environmental engineering and sciences, geography and spatial sciences, geosciences, and social sciences) for solving scientific problems and improving decision-making practices, resulting in broad and significant societal impacts (Wilson and Fotheringham 2007, Wang and Zhu 2008, NRC 2010 cited by (Wang, et al., 2013)).However, conventional GIS software based on closed and monolithic architecture is limited in its ability to efficiently handle very large spatial (i.e., geographically referenced) data and effectively manage sophisticated spatial analysis/modelling (SAM) and visualization (Wang, et al., 2013).
Figure 36 - CyberGIS Component Architecture (Wang, et al., 2013)
In this context, the following definitions emerge:
- Cyberinfrastructure (CI) consists of computing systems, data storage systems, advanced instruments and data repositories, visualization environments, and people, all linked together by software and high performance networks to improve research productivity and enable breakthroughs that are not otherwise possible (Stewart et al. 2010 cited by (Wang, et al., 2013)).
- Cyberinfrastructure-based GIS (CyberGIS) has emerged as a fundamentally new GIS modality comprising a seamless integration of CI, GIS, and SAM capabilities, likely leading to widespread scientific breakthroughs and broad societal impacts (Wang and Zhu 2008, Wright and Wang 2011, Wang et al. 2012 cited by (Wang, et al., 2013)).
The CyberGIS Component Architecture according to (Wang, et al., 2013) is presented in Figure 36.
PS: This text is extracted from my Master's Thesis in GIS and Science (published at RUN: The implementation of an Enterprise Geographical Information System to support Cadastre and Expropriation activitie… ) Dissertation's State of Art Chapter 2.
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Tomlinson, R., 2011. Thinking about GIS. Geogtaphic Information System Planning for Managers.. Fourth Edition ed. Redlands, California, USA: Esri Press.
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