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Geovisualization is the short form of Geographic Visualization where a spatial data is used to generate hypothesis and solve the problems. Geovisualization is about working with maps and other views of geographic information which includes interactive maps, 3D scenes, graphs, data and schematic views of network relationships.
In the present document, we are going to Investigate and discuss the emergence of Information Visualisation Systems and discuss the theory of Geovisualization with respect to socio-demographic data and geographical data utilised for location analysis. In addition to this, information on types of data involved in Geo-information systems and it origin of GIS and other aspects are being explained in detail.
With the availability of sophisticated computers at a lower cost, strived a way for the storage of geographical data. Geographic Information relates to specific locations with the help of data associated with the physical environment. GIS is a collection of computer hardware and software designed to efficiently create, manipulate, analyse and display all types of geographically or spatially referenced data.
The purposes of this report are to;
Investigating the fundamentals of visual perception, cartographic visualisation and the map as a visual information system.
Explore the origins of GIS and cartographic representation.
Identifying types of data involved in Geo-information systems. E.G. Use of Excel to gather data. Use if GIS to analyse data.
Explore the principles of thematic mapping and data visualisation within a software environment.
What does GIS include?
A Geographic Information system combines Cartography with a database management system. The main process is included in the functioning of GIS:
In the first, includes a system that allows the collection of data from various resources that is to be used and analyzed for some purpose. Secondly, the collected data is stored by the means of computer hardware and software. This stored information is used for data management and analysis and used to display data manipulations on a computer monitor. And finally, this processed data is used to generate hard copies of maps, images and other output types.
GIS is a measurement of natural and human made phenomena and processes from a spatial perspective which are associated with systems; elements, attributes, relationships. The information is stored in the form of digital format where the linked features can be of points, lines and area types.
GIS is unique as it handles SPATIAL information i.e. the information referenced by its own location in space and makes connections between activities based on spatial proximity. It provides the mechanism for undertaking the manipulation ad display of geographic knowledge.
For Geographers the concept of GIS in not new since GIS is being used for many years being operated manually. For example: "In the London Cholera epidemic of 1854 Dr. John Snow was able to locate the source of the outbreak by plotting the locations of fatal cases".
The technology of GIS was developed from the areas of CAD system, Digital cartography and Data Base Management System where, digital cartography is the replacement for manual process which further progressed to the evolution of CAD. The use of Data Base Management Systems (DBMS) is very important to the current concept of GIS which involves the integrating of spatial and non-spatial data. The development of relational DBMS was particularly significant with examples such as Oracle being widely used today.
THE GIS APPROACH
A Geographic Information System (GIS) is software and hardware able to manage and analyse geo referenced data and attribute data together. Attribute data refers to any type of descriptive or statistical data linked to geographical features. Geo referenced data is associated with geographic co-ordinates, which give the data some location in space. Data in a GIS are stored as map layers and output is usually in the form of maps or data tables. What distinguishes GIS maps from paper maps or maps generated with computerised cartographic programs is their link to information contained in a database. In this sense, GIS map layers may be thought of as "higher order" maps.
The ability to integrate spatial and attribute data enables a GIS to not only visually represent landscape features, but to associate these features with a host of descriptive and spatial information and use this information together in analysis to generate new information. For example, a GIS map of lakes in Sweden can show the distribution of lakes throughout the country just like any map. In addition, the same map could be used to provide information on mean depth, mean seasonal temperature, benthic conditions, acidity level, nutrient content, species composition, and income generated from tourist visits, number of households along the shoreline, etc. for each lake.
This map could then be combined with other GIS map layers in a spatial analysis to generate new information. The analysis may be quite straight forward. For instance, in combination with a land use map, it could be used to identify all the lakes with farmland of more than 100 hectares within 3 km of the shoreline. Or, in combination with several map layers, it could be used to identify the key landscape characteristics related to successful nesting of a threatened waterfowl species. GIS analyses can also be quite complex, utilising a host of spatial modelling techniques.
Technically, GIS software packages may be fundamentally different from one another. Any GIS, however, will contain a series of operations which allow it to perform three primary functions: present the current data, find new patterns in current data, and calculate new information. These operations can be grouped into four functional categories.
First, a GIS will have retrieval, classification, and measurement functions which can be used to show patterns in data or present data in an illuminating way. They have the ability to answer questions, generalise data according to some specified category, calculate area, perimeter, distance, etc.. The second group of GIS functions are the overlay operations. Overlay operations, allow the user to combine several map layers using either arithmetic operators such as addition, subtraction, multiplication, etc. or logical operators such as "and", "or", "yes", and "no". Thirdly, GIS systems have neighbourhood functions. Neighbourhood analyses are useful for determining the characteristics within user defined locations or for calculating distance or travel time between various locations. Finally, any GIS will be able to perform a series of connectivity functions. Connectivity functions involve moving through space and accumulating quantitative or qualitative totals. They may be used for a variety of analysis, from defining contiguous areas or buffer zones, to modelling water flow patterns, estimating the impact of an oil spill, or determining the fastest traffic route through a city at rush hour. Used together, these operations have a large range of analytical capabilities which makes GIS a powerful tool in any study where geographic location is an important characteristic.
Using the GIS Database for Anaylsis
There are numerous ways in which the map layers in this database can be combined to generate new results. In this article we use the maps to generate basic statistics on land use and population in south Wales. These results are reported below. In addition, we present results relating the distribution of land cover and population as a function of distance from the coast, and discuss future applications of the GIS database.
WALES AND ITS GEOGRAPHY
Wales is just over 20,000 square kilometres in size. At its widest it's 200 kilometres east to west, and 250 Kilometres north to south.
The largest mountains in the north are part of the Snowdonia range, with the largest mountain being Snowdon at 1,085 metres. There are over 1300 kilometres of coastline ranging from long flat sandy beaches to towering cliffs.
Application of GIS
GIS making use of system software and hardware, helps the user to capture, store, analyse, and manage spatially referenced data. Based on the above mentioned queries, GIS has transformed in to a multitude of purposes. Today it will be and use to build a location analysis model for the local authority that could help them in their quest to assess best possible placements for pre-school crèche facilities. The chosen Authority is in fact Cardiff. Using a demographic data of under 4 was from the 2001 census via Neighbourhood statistics and map the number of 0-4 year old children was plotted in each of Cardiff's 41 postcode areas. As a result figure 1 was obtained.
Figure 1 details the spread of 0-4 year olds in the Cardiff Area.
At this stage one can identify the postcode areas which need attention by the local authority, for placements for pre-school crèche facilities. Referring to figure 1 they tend to be the areas which are shaded in the dark gray or black. Figure 2 shows these areas with reffrence to a actual geographic map.
Figure 2 Thematic map of the Number of 0-4 year olds in the Cardiff postal code areas with Cardiff map.
To further refine the a location analysis model for the local authority that could help them in their quest to assess best possible placements for pre-school crèche facilities other use full dataset could be introduced such as current location of pre-school crèche facilities, with the number of lone parents and the number of households that have both parents in full time employment.
The objective of this report was to review current literature about the fundamentals of visual perception, cartographic visualisation and the map as a visual information system. Also the report explores the origins of GIS and cartographic representation. It was also identified that various data sets could be used in Geo-information systems to build a location analysis model which can be used by for example local authority that could help them in their quest to assess best possible placements for pre-school crèche facilities, these datasets could include not only Age structures but also the number of lone parents and the number of households that have both parents in full time employment etc.