Geographical Information Systems (GIS)

Introduction
Geographical Information Systems (GIS) are integrated computer systems for the input, output, storage, and analysis of spatially referenced information. These systems integrate modern acquisition systems and management tools for application in the solving of problems relating to geospatial information. Some of the special tools used in
GIS include remote sensing tools that gather the information of an area from a distance with the help of radars or cameras on aircrafts or satellites. These geographical tools help in the study of natural features, resources, and changes in the earths climate. The acquired data developed in visualization software that uses 2D or 3D animations and images. GIS is a revolutionary technology that has changed how humans interact with space because it facilitates the tackling of novel problems in scales that were previous unimaginable several decades ago. The systems facilitate the handling of geographical challenges, such as earthquakes and climate change on a global scale. The application of this technology fosters greater insight into specific geographical problems and the development of innovative techniques for meeting these challenges.
Geographical Information Systems (GIS)
It is impossible to work with maps and geographical information in the modern world without encountering the term GIS. Although the GIS industry emerged during the 60s, it benefited enormously from the technological advancements that starting during the 80s and resulted in a major improvement in computer software and hardware. In its most basic form, GIS facilitates geographical access to records. GIS requires specialized input-output devices that employ specialized techniques to storage complex geographical information. However, regular databases can store and respond to basic GIS inquires. GIS gives users the capacity to retrieve attributes of a location or match attributes to locations that bear the attributes. Therefore, GIS is a digital representation of conventional geographical information and is useful in answering routine queries. The systems have found application in both the government and companies. Governments use the system to track land ownership, taxation, disasters, and developments. Companies use the system to track infrastructures, such as pipes, transformers, and valves.
The first attempt to visualize geographical data was done with a VRML interface that explores geographical databases. The VRML interface enabled the access of positional information using VMRL sensors. Later, GIS data was integrated with CAD/CAM and DPS with the help of 3D web in a desktop environment. This enabled the modeling and rendering of geographical terrain and buildings. The Common Object Request broker Architecture (COBRA) facilitates interaction with 3D spatial databases in WWW.GOOVI-3D using java and VRML. Two extensions were added to facilitate functionality. These include SQL and Name Dictionary Management nodes. Later, a Web 3D GIS was developed with a capacity for distance measurement, 3D buffering, lantern selection, and near analysis. VRML is a favorite for GIS developers because it serves as a cheap platform that provides quality interactive visuals and is compatible with java.
VRML is a display tool mainly used in CGI-based servers. A major limitation facing the use of VRML is the reliance on the clients web browser to generate the VRML file using an ActiveX plug-in or Java applet. Users rely on 2D web interface to submit queries to a Web GIS system. This has serious limitations when visualizing large areas because it requires considerable interaction speed that most Internet connections cannot handle cheaply. 3D terrain visualization is data intensive and is the main component of many GIS files. This is because it forms the background for attribute distribution, buildings, topography, and roads. Seamless generation of terrain information with other layers of GIS information is essential for the successful operation of the Web 3D GIS. VRML performs poorly when attempting to visualize a large area. This is because its uses the one point to all contours method. Points at the same contour level are loaded simultaneous, which take more time than a user can wait, especially for real-time applications.
An innovative solution to the prolonged time it takes to load is the use of a tile based selective visualization method for large areas. This improves real-time visualization of large areas by combining the advantages of 2D and 3D interfaces. The method facilitates a dynamic link that enables speedy retrieve of geodata through concurrent processing. The approach not only facilitates a multi-resolution visualization, but also intelligent enquiry system in a web 3D GIS. The visualized map floats on a 2D panel on a 3D scene. The map has capabilities to track view points in the virtual world with coordinates to give the user have a positional reference. There is an information board to give the user geographical information about the area in display. There is a query pad to allow the user to search specific information from the database. The system functions on an integrated VRML browser with a Java applet. A Java Database Connection (JDBC) retrieves data from the server and facilitates communication between embedded scripts.
Symbologies are used in GIS to graphically represent data and enable the viewing of large amounts of data on the same map in real time. Modeling software is adapted to build 3D cartograms that extrude spatial data using different heights in accordance to statistical indicators. Cartograms are representations of geodata that include the conservation of data with suitable variation, such as shape, contiguity, and orientation. Effective legend designs and recognition of enumeration units determine the accuracy of map reading. Cartograms are not maps, but representations of objects depending on certain attributes. There are three main cartograms with varying accuracy in depicting a map. Some look almost like a map while others do not. These include contiguous, non-contiguous, and Dorling cartograms. Contiguous cartograms maintain topology. These may cause distortion of the objects; therefore, the cartographer must use an appropriate size to ensure attribute values are evident. Non-contiguous cartograms do not maintain topology. This is easier to maintain size and resize the objectives. Dorling cartograms do not maintain shape or topology. Objects are replaced with uniform shapes, such as circles.
GIS is increasingly supporting efficient decision making when and where it counts. The capability of GIS to combine different sets of data into a 3D visualization enables the easy access of information and optimizes analysis. This technology is important for facility managers because they apply the spatial insight they gain from GIS to manage various operations in the facility. Some of the geospatial support that the system enables managers to access includes organizing tasks carried out in multi building or sites to reduce the logistics and transportation cost. GIS facilitates the visualization of energy consumption information in specific sections of a building while maintaining an overview of the facility. It is easy to analyze space use and availability to optimize its use. GIS also facilitates evaluators to conduct evaluation tests that determine standard adherence and inventory of assets. This is possible because the system facilitates the capture of location details of assets enabling rapid visualization. The system facilitates the evaluation of building for compliance with the disability Act. GIS facilitates the impact of projects on a campus' environment and determination of different line of sight during special events.
GIS plays a critical during search and rescue missions in the event of an emergency or disaster. GIS provides information, which is critical for coordination and decision-making. The system has the ability providing visibility to a disaster and can determine how resources are mobilized at both a national and international level. Information is important for providing timely and relevant assistance to those in a disaster. The information is also important for post-emergency analysis, which important for the development of better responses and development contingency measures. Most emergency response activities involve efforts from various teams making decisions under time pressure to save lives or property. Effective decision-making in an emergency requires contextual information from a control center and knowledge of other teams activities. GIS is most suitable for emergencies because it can represent the three types of information essential in emergency response activities.
The knowledge essential in the management of an emergency includes formal knowledge from government records. This outlines the area as it was before the emergency and possible infrastructure that could aid the search and rescue activities. Knowledge from field agents and rescued victims help develop the situation on the ground and possible limitations that the rescue teams may face. Personal knowledge from locals adds details that may be missing in formal information. This information helps in decision-making and increase the effectiveness of the efforts. The information is dynamic and requires constant update to ensure teams adapt to emerging issues. GIS is best suited for this role because it combines information for easier analysis and can easily be updated by field agents in real-time using specialized mobile applications. This open source solution delivers valuable information to command centers that are responsible for directing search and rescue operations. Reliable information ensures that more lives and property are saved.
The development of computer technology is accompanied by ethical and privacy concerns because the technology can be force for good or evil depending on the practitioner's motive. GIS practitioners face the same ethical challenge as other practitioners in the Information System field. The main concern over GIS technology is that it is used to achieve benefits for the society and not to harm it. Issues raised include privacy concerns and access to GIS databases. Conflict issues include privacy demands, demands for open access, and maintaining system security. Although the issues remain largely unresolved, there is consensus that the field requires a code of ethics that outlines standard acceptable behavior. GIS practitioners are facing a dilemma that is not likely to end soon. The collection of detailed data about individuals and withholding that data from the public is in violation of individual rights. This is because the developer of the system reserves subjective autonomy but treats other objectively. Allowing open access to the information only allows participants to participate in the project only to the extent they are willing to objectify themselves. The participants are limited in participation because they cannot maintain their individual autonomy if they choose to become participants.
The development of GIS is a result of linking many parallel developments in different disciplines involved in the processing of spatial information. These include cartographers, surveyors, photogrammetrist, geographers, and spatial analysts. For these disciplines, GIS facilitates better analytical techniques because it extends the ranges of possible analyze, especially for quantitative geographers concerned with occurrences taking place over wide geographic regions. Other than ethical issues, the field faces technological limitations, especially for real-time application.
Conclusion
GIS is a new area in geography. While it has proven to have the potential to aid in many human endeavors, there is no definitive work to mark it as a major advancement in human technology. The system fosters insight into geographical problems and helps in the analysis of interrelated information to develop solutions. As the system continues to develop, it faces the object-subject challenge. It unlikely that this challenge will be resolved soon because visualization of the world infringes on individual rights to privacy, limiting access to information on GIS databases violate individual right of access to information. GIS practitioner will justify the technology if they use it ethically and ensure it does more good than harm to humanity.