Geographic Information Systems and Technologies - Case Study Example

Geographic Information Systems and Technologies 1.0 GEOGRAPHIC INFORMATION SYSTEM - GIS  A Geographic Information system is a modern device that assists in the data capture, storage and subsequent data management and analysis of spatial earth data and information. This geographically referenced information has been widely helpful to the purpose of research, resource management, natural emergency management, corporate marketing and law enforcement. 2.0 History   Geographic Information system came into existence in the year 1854, when Sir John Snow exercised the concept of GIS in making a map with directions during a Cholera outbreak in the city of London. Sir John had used directions for places which were affected with the disease and some other individual cases. This directional map assisted the doctors to find out the exact cause of infection, which was in this case – an infected water pump and therefore, preventive measures were taken up instantly, (Foresman, 1997). This concept of collecting all relevant case information on a directional map and then analyzing the data was the basis for the Geographical Information systems.   Fig 1: Map showing clusters of Cholera cases in London by John Snow  The factual image or the current form of the Geographical information systems came in the year 1962, when it was developed by Dr. Roger Tomlinson , a research scientist working with the Federal Department of Rural development, Canada. This system was invented under the supervision of the Land inventory department of FDRD, Canada, which used it to collect and evaluate land information in Ontario, (Chang, 2008). This information was to be utilized for the purpose of soil study, plantation, land vegetation and other forestation studies. The basic features of this first Geographical information systems model consisted of mapping, layer superimposing, sizing, levelling and scanning.  This model also boasted of a co-ordinate system that could easily inter link any area on the globe and rescale as per requirements. The utilization of layer superimposition and overlaying in the case of extending the method of spatial analysis of geographical data was also provided in this model of GIS. In spite of these relevant utilities, this model was never marketed and sold for commercial intentions.   However, during the late 1980’s, the first commercial model of Geographical information system was developed by the M&S Computing research Institute based on the integration of the two models (Sir John Snow and Dr. Roger Tomlinson). This model was intended for marketing and selling purposes and had the latest technique of spatial attribution, and organizing of data with the help of database structures. With the commencement of the 20th century, there was a speedy onset of a variety of techniques in the Geographical Information systems related to every commercial and non-commercial field, (Chang, 2008). Also, with the random augmentation in the number of free open source commercial GIS systems, a variety of GIS acceptable operating standards and systems have been devised to match up the varied and precise customer requirements.   3.0 GIS Systems and Technologies The contemporary GIS systems utilize information in its digital form, and there are many techniques available to convert the gathered data into digitalized form. The most commonly used method of digitization is where the hard copy of the information (which is usually in the form of a map /survey), is converted into its digital form with the help of CAD programs and geo-referencing abilities of the reference GIS systems. One of the most modern methods of heads-up digitalizing the geographical information is through the ortho-rectified imagery (both from satellite and aerial sources). The heads-up method of digitizing the data is based upon the tracing of geographical information straight on the head of the aerial imagery rather than using the conventional form of tracing the geographic data on a different digitizing tablet, which was originally the heads-down digitizing method, (Coppock, and Rhind, 1991). Vice-verse, GIS systems are also capable of converting the digital information into a map form which can be utilized for study and analysis purposes. 4.0 Information linking through sources in a GIS Geographical information system employs the spatial-temporal position as the main index variable for GIS data. As in the case of any relational database which consists of text or statistics, it can be related to various tables through a universal key index variable, Geographical information systems can also link information (both related / unrelated) through its key index variable – location or space time variable. Any location that can be referenced in the form of spatial variables can be utilized by Geographical information systems and represented in the form of x, y, z co-ordinates which denote the longitude, latitude, and elevation, of that location. These Geographical information systems coordinates may represent other quantified systems of temporal-spatial reference. Geographical information systems offers the facility to analyze, interpret, and represent a large diversity of geographical data that is linked through an accurate spatial information system, that subsequently assists in decision making in the fields of agriculture, medicine, education, urban planning etc. This particular feature of the Geographical information systems has definitely initiated a new beginning for innovative opportunities of scientific investigation and research into behaviors and prototypes of earlier measured unconnected real-world geographical data. 5.0 GIS Data Representation The Geographic Information System is capable of presenting the real time objects like land, roads, height etc, in the digital form or with the help of digital data which in that case represents the mix. This real time data is categorized into two types - discrete and continuous data. Discrete information / data can be examples of a concrete structure, piece of land, etc., while continuous data / information is example of altitude, or level of rainfall in an area. In order to map these two different types of data sets, Geographical information system has two methods of data storage - raster images and vector. These two methods of data referencing in GIS make use of points, lines, and polygons. Another hybrid technique of data storage for GIS systems is the identification of point clouds, which are basically a combination of three-dimensional points with RGB data for every point of the scanned area,which presents a 3D color picture, (Heywood, Cornelius, & Carver, 2006). In this section, the two main methods of data representation in Geographical information system systems are discussed:   1.   Raster method – Any digital data / information stored in the raster form is basically am image which can be sized in variable dimensions with  the help of grid structures. A raster graphics pixel is the tinest grid and forms the building blocks of a digital image.  A combination of these raster pixels, makes up an image and can be easily differentiated from points, lines and polygons, (which are vector representations). The raster type of data is basically a digitized abstraction of real time objects with the help of grids and map relief schemes. The most common form of raster images/ data is basically in the form of area, and in some other cases with highly developed Geographical information systems, raster data representation accompanies elevation data, a digital elevation model, or wavelength information, or other electromagnetic indicators. 2.   Vector method – Vector representation makes use of geometrical shapes to represent data in a GIS. The geometrical shapes used in a raster method are points, lines, and polygons. In a simple case example, points are used up for representing wells, rivers as lines, and polygon for a natural water resource like sea, lake etc. 2.1 Points – Points are basically single point reference to relate to geographical information like well, mountain peaks, destinations, and other trail points. At times, when the information has to be displayed in a small scale, point system can be used randomly. However, point system does not allow measurements in the GIS map. 2.2 Lines – these are one dimensional reference that are used in Geographical information system maps to represent rivers, tracks, rods, and other trails. Lines are capable of measuring distances in a GIS map unlike the points. 2.3 Polygons – Polygons are two dimensional referencing that are able to cover areas in the digital GIS map. Polygons are used to represent lakes, water reservoirs (both human and natural), buildings and other land options. With the help of polygons, perimeter and area in a map can be easily measured.  Vector characteristics in a Geographic Information System data set can also be altered to maintain the spatial characteristic or integrity of a particular data / location, with the application of certain topology rules. A simple basic rule used in Geographic Information Systems is that the polygons must never overlap each other.  Both the continuous and varying continuous data sets can be easily represented with the help of vector data representation method. The contour lines and triangulated discontinuous areas and networks are used to characterize the elevation / height above sea level and other examples of continuous values. The triangulated discontinuous areas record the values of a point location which are in the form of a mesh formed with the help of lines connected from each other signifying other areas and point locations, (Fonseca, Frederico; Egenhofer, Max, 1999).                     Fig 2: Raster Form Data Map                                Fig 3: Vector Form Data Map 6.0 Advantages and Disadvantages This section presents some major noteworthy advantages and disadvantages of using a raster or vector data model to correspond to geographical data and information: Raster form of data are capable of recording a value for all the points that are a part of a given area, but in the case of vector form of data storage and recording, comparatively much larger space is needed and it stores data of points only that are required. It does not automatically store all the points in the given area as the raster method. In the case of raster method, overlaying actions and other layering tasks are much easier as compared to in the vector method, (Goodchild, 2010). In the case of traditional directional maps, vector data representation proves to be much more helpful as vector data can be portrayed in the form of vector graphics.  However, the raster data represents itself in the form of an image, which may at times block other objects. (This may depend upon the map resolution of the raster data file) Scaling, registering, layer integration and re projecting of geographical data is more easier in the case of vector representation than raster representation. Vector data is more attuned with relational database surroundings, where the vector information can be in the form of a table / column and be executed with the help of different operators. Raster data file size can be extended upto 10 to 100 times larger than the vector data files. However resolutions of the files play an important part. Raster data needs to be completely reproduced, while at the same time vector data can be easily updated, edited, and maintained in several ways. Vector data is much easier to manage when network maps are concerned, (Goodchild, 2010). 7.0 GIS Uncertainties The preciseness of the results given by the Geographical information systems rests upon the source data and the procedure that is applied to encode the source to reference data. Geographical experts have been able to obtain excellent results related to location accuracy by using the Geographical information system results. With the powerful technology, Geographical information system has been able to enhance the utility and capacity of the system and offer better services for the advantage of the society. However, there are a few issues that may clog the efficiency or utility of the Geographical information system systems. As an example, the use of paper maps has been found to seriously affect the sizing and dimensional capacity of the Geographical information system. Discussing in brief this issue that while creating a digital topographic database for a geographical information system, the main source of data are the topographical maps. However, images of Ariel snapshots and satellite photos are also a source for collecting information which can also be mapped on various layers for the same topographic database. However, the primary source of information still remains the topographic maps. In this case, the scale of these topographic maps and the area representation method are very significant. To digitize the available topographic map, the map needs to be converted into raster data format and the resulting raster information is then given a theoretical dimension by a rubber sheeting method. The topographic maps were generally created many decades ago, with the Cartographers giving low importance to the accuracy of the spacial data. There existed no common norms for the creation of these topographical maps at that time which resulted in poor map accuracy, (Clarke, 1986). Moreover, the use of pen and paper for drawing a topographic map was not meant to be utilized for sophisticated technology usage like the GIS. Today, the equipments that are used to make Geographical information system maps are much more sophisticated and precise. Therefore, the fact is that there are uncertainties of spatial accuracy in the topographical maps and this uncertainty transfers to the system into the GIS maps making the digitalized maps inaccurate as well. 8.0 GIS and its Applications 1. Natural Resource management Geographical information system helps farmers and geologists to obtain the soil properties - chemicals and fertility of the soil and the nutrition level of the soil. GIS information is used for the application of variable rate technology which is employed by agriculturists to then adjust the soil fertilization and other inputs as per the requirements of the soil. Also GIS helps to evaluate and analyse the rainfall patterns for both small and large areas, the gradient of a particular area, employment and labor availability in an area, good transportation facilities and population of an area. GIS assists the experts in identification of locations and places which need extra security from natural calamities like floods, (DeMers, 2005). Watersheds are an effective measure to curtail the floods and promote the efficient management of water resources. Further, Information provided by the GIS helps to assess the vulnerability of these watersheds to soil erosion, and the risks of fires and floods. 2.      Urban Planning  City planners and developers frequently make use of Geographical information system to prepare strategy, which assists in shaping the policy standards and making efficient decision related to urban and other community development activities, (Chang, 2006). GIS provides spatial data related to parcel, zones, area usage, addresses, communication and transportation facilities, and housing plots. The city planners can also keep a track of future requirements and accordingly plan quality life for the society. 3. Emergency Services and GIS   The above shown two plots reveal how the various cases of urgent service situations can be plotted on a GIS map. This data has been retrieved with the help of calls that have been registered for emergency health care services and fire rescue services in a state during the time period of 12 months. The total number of calls per year can be over 15,000 and contained data like address, telephone, and location of the caller and then this information has been transcribed into a GIS map, (Dangermond, 1980).  To further note, each set of this information, like telephone number, address and location is stored in different layers of a GIS. This example offers an ideal illustration of how GIS be capable of providing information and assist in the decision-making process as well as any future planning of national medical services. With this productive arrangement and efficient storage structure of critical national data, a number of queries can be resolved.       4.      E-governance Geographical information system has been very effective in implementing e-governance standards by the government. Fast and easy access to maps and Internet allows the government agencies to offer efficient services to the public. Services like Online mapping, online banking, funds transfer, university submissions etc. have helped government to develop business and public services, (Chang, 2006).  5.      Hydrology  GIS helps to study the underground water quality and the risks that are faced by the underground water levels and purity. During the various urban planning activities like constriction, deforestation, housing, agricultural activities, plantation, industrial set ups, it is important to know the water levels and the risk the underground water level faces due to the impact of these activities. Moreover, the level of contamination in the underground water and subsequent cleaning up, is usually planned with the help of GIS information, (Goodchild, 2010). An added example with reference to the use of Geographical information system deals with a widespread crisis related with groundwater pumping and land subsidence or infringement in coastal regions. 9.0 References 1. Clarke, K. C., 1986. Advances in Geographic Information Systems, Computers, Environment and Urban Systems, Vol. 10, pp. 175-184. 2. Fonseca, Frederico; Egenhofer, Max (1999). "Ontology-Driven Geographic Information Systems". Proc. ACM International Symposium on Geographic Information Systems. pp. 14–19 3. Heywood, I., Cornelius, S., & Carver, S. (2006). An Introduction to Geographical Information Systems (3rd ed.). Essex, England: Prentice Hall. 4. Chang, K. T. (2008). Introduction to Geographical Information Systems. New York: McGraw Hill. p. 184. 5. Coppock, J. T., and D. W. Rhind, (1991). The history of GIS. Geographical Information Systems: principles and applications. Ed. David J. Maguire, Michael F. Goodchild and David W. Rhind. Essex: Longman Scientific & Technical, 1991. 1: 21-43."The history of GIS.". http://scholar.google.com/scholar?cluster=13820827634229141183&hl=en&as_sdt=10000000000000. Retrieved 2010-09-17. 6. Tim Foresman 1997 The History of GIS (Geographic Information Systems): Perspectives from the Pioneers. (Prentice Hall Series in Geographic Information Science) Prentice Hall PTR; 1st edition (November 10, 1997), 416 p. 7. Goodchild, Michael F., (2010). Twenty years of progress: GIScience in 2010. JOURNAL OF SPATIAL INFORMATION SCIENCE Number 1 pp. 3–20 doi:10.5311/JOSIS.2010.1.2. July 27, 2010. 8. Dangermond, Jack.1980."Some Trends in the Evolution of Geo-graphic Information System Technology."Environmental System research institute, Redlands, California 9. Chang, Kang-Tsung (2006): Introduction to Geographic Information Systems. 3rd Edition. Mc-Graw Hill. (ISBN 0070658986) 10. DeMers, Michael N. (2005): Fundamentals of Geographic Information Systems. 3rd Edition.Wiley. 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