GEOG 1230 Lecture 2 Types and Sources of Geographical Data.

GEOG 1230

Lecture 2Types and Sources of

Geographical Data

• Geographical Data Defined• Components• Importance• Types of Data• Data Sources• Your Assignment• Next time

Lecture Structure

Geographical Data Defined

Data defined:• Facts about a phenomenon that enable us to

understand, explain and make decisions• OED - something known or assumed as fact,

which forms the basis of reasoning or calculation

• Data are NOT information, we turn data into information

Example…

Geographical Data Defined

IF• Geography is concerned with the description

and explanation of phenomena that occur on (or near) the Earth’s surface

THEN• Geographical data are facts that describe

these phenomena and their location on the Earth

Components

• Geographical data has three components:

• Temporal component - provides a record of when the data was collected

• Thematic – describes some attribute or variable of a phenomenon (geographical)

• Spatial – describes geometry, location or shape

Temporal Component

• In the form of:

• a record of when the data was collected• a series of repeat data sets at different times

Thematic Component

• Can include non-spatial descriptive or quantifiable characteristics including:

• Socio-economic information• demographics• housing statistics• migration• transportation• economics• retailing

Examples

Thematic Component

• Environmental or natural resource information

• geology• vegetation• hydrology• soils• topography

Example

Spatial Component

• The spatial component can be recorded using one of two models:• location orientated approaches; or• object orientated approaches

• Location orientated• where every element in an image are

assigned a spatial reference• Time is represented as multiple images

Example

Spatial Component

• Object orientated using spatial entities including:

• points – 0D (no length/breadth/depth)• lines – 1D (length)• polygons – 2D (length/breadth)• volumes – 3D (length/breadth/depth)

• Time is recorded using separate data layers

Example

Importance

• Why do we need geographical data?

Everything is related to everything else but things that are near to each other are more

related than things that are far apart

Example

Importance

• Why do we need geographical data?

Everything is related to everything else but things that are near to each other are more

related than things that are far apart

• Not always true but illustrates the importance of spatial relationships

Importance

• Collecting and analysing data about the world in which we live helps us:• simplify very complex surroundings into

understandable, shareable information • get from place to place• understand past, present and future social

organisation and behaviour• understand how/why we use resources

• Our behaviour in space often reflects our past patterns of behaviour

Types of Data

• There are many ways of categorising geographical data:

• primary/secondary• qualitative/quantitative• human/physical• by method of collection

Primary/Secondary

• Not just a geography issue

• Primary data - collected and analysed by the same individual

• Secondary data - collected by someone else

• Why is this important?

Qualitative/Quantitative

• Qualitative data are• non-numerical and can only be classified into

categories• i.e. colour, education level, male/female

• Quantitative data are• measured on a numerical scale• represents a quantity or amount of something• i.e. height (in cm) or weight (in kg)

Human/Physical

• Why is this a fundamental division in academic geography (i.e. BSc and BA)?• often require different approaches• often require different background info

• However:• very difficult to divide• many sub-categories and areas of overlap• Example: soil data

By Method of Collection

• Data can be classified by the method it was collected:

• direct measurement• remote sensing – photography, satellite• cartographic – derived from maps• administrative and statutory – by-products of

other processes• census and surveys

Data Sources

• There are many sources of geographical data• some are still only in hardcopy• many are available digitally• many are available online

• Examples?

• This is going to be your job!

Your Assignment

• In the library (allow ~1.5 hours)• compile a list of at least 6 sources of

geographical data. Provide:

• the name of the source• where it can be found• a 1-2 sentence description• publisher• other useful information

Your Assignment

• use the library catalogue, Athens resources, the internet and other library resources

• Submit in box in basement of main building by Wed Oct 15th

Next Week

• Your input will be compiled• Will discuss some sources of geographical

data