Sunday, April 1, 2007


GIS 2007 Assignment 4


A map can be simply defined as a graphic representation of the real world. This representation is always an abstraction of reality. However it is impossible to capture all of the complexity found in the really world, this is due to the infinite nature of our universe. For example, topographic maps abstract the three-dimensional real world at a reduced scale on a two-dimensional plane of paper, ( Maps are used to present both cultural and physical features of the environment. Standard topographic maps show a variety of information including roads, land-use classification, elevation, rivers and other water bodies, political boundaries, and the identification of houses and other types of buildings ( Use of computers resulted to introduction of digital maps which are maps stored in a digital format accessible on a computer, rather than paper. Maps are also displayed in a form of GIS which is a computer system designed for storing, manipulating, analyzing and displaying data in a geographical context.

Printed maps
Printed maps display the geographical information of the whole earth or part of it on a flat surface, for example on paper sheet. Maps are rarely drawn at the same scale as the real world. Most maps are made at a scale that is much smaller than the area of the actual surface being depicted. A 1:50 000 maps tells us that something on the map will be 50 000 times smaller than it is in real life.
There is difficult for representing the true shape of the earth’s surface on a map, especially when this depiction is illustrated on a two dimensional surface. Cartographers have overcome this problem by developing a number of standardized transformation processes. However all of these transformations create some type of distortion artefact. The nature of these distortions is related to how the transformation process modifies specific geographic properties of a map. The geographic properties of a map affected by projection distortion include area, distance, straight line direction between points on the earth and the bearing of cardinal points from locations on our planet (
The data set is not an exact duplication of the printed maps, and some elements of the printed map are not reproducible due to the limitations in equipment used ( In printed maps it is difficult to focus area of interest and some layers can not be modified but can however be printed. Labels of printed maps cannot be modified thus making printed maps not up-to-date. Unlike digital map, printed map once printed can not be change in the way they look. One of the advantage of printed maps is that without much instruction you can read and use it to perform basic navigation purpose (
Also printed maps provide us with big picture of the area around our location and they depict land marks, roads, waterway etc. in great detail.

Electronic map
Electronic map data is map detail held in the form of national grid coordinate values and codes, which can be stored and manipulated on computer ( Electronic maps have some similar characteristics with printed maps but in general electronic maps are seen as more useful since they contain updated data. Updating electronic maps is much easier and fast, however it requires use of high technology computers and internet, which is expensive, thus in most cases updating the maps is not possible. Unlike printed maps, electronic maps contain not much detail but you can change the scale of the map (zoom in or out), also you can identify an item on the map and create a path to it along with navigation assistance to keep you on track to your destination ( The method in which the map displays its features can be customised by controlling the size of the text, removing some items to simplify the amount of items ( While printed maps provide great details and large view of the map area, electronic maps can display only a small area in detail, they can ultimately depict the entire earth and have the added convenience of zoom in and zoom out map scale selection ( Electronic maps such the GPS are very useful nowadays as they can be used to locate any place anywhere in the world.
GIS (Geographical Information System)
A GIS is a system for capturing, storing, analyzing and managing data and associated attributes which are spatially referenced to the earth, ( In the strictest sense, it is a computer system capable of integrating, storing, editing, analyzing, sharing, and displaying geographical-referenced information ( In general, GIS is a tool that allows users to create interactive queries (user created searches), analyze the spatial information, edit data, maps, and present the results of all these operations. GIS is most often associated with maps and they provide a great deal more problematic-solving capabilities than using a simple mapping program or adding data to an online mapping tool (
The limited capabilities of internet GIS are especially difficult for our country atlas. Internet –based map services have many problems as well. The maps are of an almost universal poor quality, the internet reaches only a minority of the world’s population, current internet GIS server software is very expensive, map services are difficult to create and maintain (most require extensive programming to create a usable service), and their capabilities are limited (
GIS use made life easier in that it is used in a wide range of applications, GIS technology can be used for scientific investigations, resource management, environmental impact assessment, urban planning, cartography, criminology, history, sales, marketing and route planning (
For example, a GIS might allow emergency planners to easily calculate emergency response times in the event of natural disaster; a GIS might be used to find wetlands that need protection from pollution.


Internet source: accessed on 29/03/2007

Internet source: accessed on 28/03/2007

Internet source: accessed on 28/03/2007

Internet sources: accessed on 28/03/2007

Internet source: accessed on 31/03/2007