1.1 What is a map? A map is two-dimensional representation of geographical features and itrepresents the reality around. However, even three-dimensional features, suchas topography, can be incorporated in a map using ad hoc symbols.
Geographical features can be both physical objects,such as buildings and streets, group of homogenous objects such as cities,woods and imaginary objects, such a geographical borders. 1.2 What is the most important entity in a GIS? The ability to form a connection between geometrical data (maps) and theattribute data (a table). The programme does this using a “link”. 1.3 What is the difference between “spatial data”and “none spatial data”? Spatial data, such as buildings, roads…, can be defined with a specificposition (i.e.
x, y and z coordinates). Non-spatial data on the other hand donot have a defined position and no specific spatial delimitation and thus donot have specific coordinates. Examples of non-spatial date are precipitation,temperature, air pollution levels… 1.4 What kind of different geometrical objects arethere in a GIS? There are three kinds of geometrical objects: point objects, lines andpolygons. 1.5 Which are the four most important functions aGIS must be able to handle? GISprogramme must be able to handle data input, data storage, data structuring anddata output, as means of communication with the user and as basic action tobuild up analysis and interpretation-. 1.
6 Describe the concept of spatial information. Spatial information means the connection of any kind of data withgeographical coordinates, as example the presence of trees in a given location,temperature at a particular location and so on. Given this spatial informationdoes not need to be static, and can describe also phenomena occurring overspace and time, as example a car moving along a road, or pollution level varyingover time in certain area.
1.7 Describe some sort of an analysis which you cando with a GIS. An example of analysis that can be implemented with GIS is the researchof the connection between income, weight and proximity of grocery store sellingfresh vegetables.
Or the distribution of soil pollutants in relation to thepresence/proximity/traffic volume of roads. With GIS it is possible to estimateand model also future impaction of particular action: for example, we couldestimate the amount of forest loss upon road construction. Therefore GIS can bea useful tool for decision makers and policy implementation. 1.8 Describe briefly how the “linking” in a GISworks.
To be able to connect different objects that belong to each other a linkhas to be established. A link is a unique identifier, a specific alphanumeric combination,assigned to objects belonging to the same group. A real life example could forinstance the assignment of social security numbers. Each of this number isconnect to a person and to several “objects” like medical records, bankaccount, gym membership… and even if there would be two person with the samename the use of a social security make impossible to mix them up. In GIS this meansthat certain specific area (geometric data) are connected to information suchas population density, pollution levels, income… and this connection is madepossible by the fact that the same unique identifier is associated -linked-with each one of this geometric data and their specific attributes. 1.
9 Describe the cycle of the GIS handling. -Datacollection-Digitalizationof data (data are transferred in a database)-Datamanagement (data from different sources can be combined, as for instance dataresulting from sampling and data obtained by other databases)-Data analysis/Statistical analysis-The analysisof results need to be communicated to the decision maker/final users as part ofthe information needed to make decision-Decision canresult in changes in the real world-To evaluatethese changes data needs to be collected…