A1 content Flashcards
Define Spatial thinking
ability to use pace as a framework
Define spatial intelligence
the balance between spatial visualisation and spatial reasoning skills
What are the map elements?
Date
Orientation
grid
title
author
index
legend
source
What is a general reference map?
map that shows the location and summarises the landscape.
What is a topographic map?
Map that the government makes with strict specifications.
What is a thematic map?
Map that shows spatial distribution, often need specialised knowledge to interpret
What is a map?
symbolic representation emphasising the relationships between elements. Represents real-features at a reduced scale and is effective for communication.
What is generalization?
Including or excluding elements of a map, when reducing the scale of a map
What are common features of maps?
Symbol, Sclae and grid.
What did technology do to maps?
It changed the way we make and the types of maps available
What is cartography?
Science and art of map-making
What is geo-visualisation?
Introduced in the 1950’s, the transition of maps from communicating to exploratory knowledge construction, includes pattern relations, trends and critical point recognition and it enables the perceptual processing of data.
What does critical GIS consist of?
critical points
Social construction of space
power and knowledge
representation and visualisation
participatory GIS
Ethics and social justice
Inter-disciplinary
What is a population?
Total set of things to be studied
What is a sample?
A portion of a population that is actually studied.
What is infernal data?
Comparing and predicting, and attempting to conclude data, making inference about the data
What is discrete data?
Showing and summarising data that is under study, presenting data in a meaningful way, explaining the known data
Raw tables
scientific information, with no overview of the data set.
How can we measure the central tendency?
Use mode, median, mean to indicate the value that is most likely centered.
Can the median be affected by outliers?
no, only the mean is affected by outliers and skewedness.
What graphs can we used to interpret raw data?
Scatterplot
hexgon bin plot
3D scatterplot
Scatterplot matric
Parallel co-ordinate plot
How many attributes can a parallel co-ordinate plot display?
can display more than 3.
Describe the correlation of a parallel co-ordinate plot
when r=1 lines are parallel, when r=-1 lines intersect at a mid point, when r=0 lines intersect
what is r the correlation coeffiecient show?
it shows linear relationships the closer r is to 1 the more linear.
when r is + the graph is positive, when r is - graph is negative
What are the complications of r ?
it doenst show outliers and it has non-parametric tests.
what is the regression line formula?
y=a+bx
is m and r proportional to eachother?
Yes
What is multiple regression
dependant attribute and multiple independent attributes
What are some considerations of m and r?
- high correlations do not imply a casual relationship
- the magnitude of r can be affected by the level at which data has been aggregated
- like values tend to group together
- regression techniques can be applied globally and locally
What Does MAUP stand for?
Measurable areal unit problem
What is a centroid? and what do they represent?
A centroid is a polygon center used as a default position for labeling. Can be used to represent a polygon (analytical) or can be used for interpolation polygons to create a continuously varying grid (raster projections).
What indexes are used for GIT?
CI - compactation index
the ratio of the area of a shape to the area of a circumscribing circle. range from 0-1 where 0 is least compacted and 1 is most compacted.
what is redistricting?
the combining of districts that are voting precincts
what is gerrymandering?
districts structured for partism benefit
what is spatial auto-correlaion?
the tendency for things to occureclose to each other in geographic space and can be measured.
What map complexity?
The degree to which the combination of map elements results in a pattern that appears to be intricate or involved.
What are the advantages of equal interval classification
easy to implement and interpret
there is no gaps in the data
has a simplified legend of class breaks
is sensitive to outliers
What are the disadvantages of equal intervals?
Doesn’t consider distribution
can lead to classes with no observations
What are the advantages of quantile classification?
Easy to implement
percentage of observations in each class is equal
works for ordinal data
What are the disadvantages of quantiles?
There are no empty classes
it doesn’t consider the distribution
it is not sensitive to outliers
has gaps
has ties which complicates it a bit
What are the advantages of mean standard deviations?
if data is normally distributed the mean serves as a useful dividing point
What are the disadvantages of standard mean deviations?
Only works if the data is normally distributed
needs basic statistics understanding
more complex
What are the advantages of maximum breaks?
Easy to implement
What are the disadvantages of maximum breaks?
Only considers large breaks
What are the advantages of natural breaks?
Very flexible
Accurate
What are the disadvantages of natural breaks?
It is subjective
What are the advantages of optimal classification?
Best classification
can determine the appropriate number of classes
What are the disadvantages of optimal?
Requires brute force to get values which is computing intensive
Gaps in the legend
What are the spatial dimensions?
Point
Line
Polygon
Volumetric
3D
Small Scale maps
is of a large area, which has been generalised, city is a point there are no buildings visible
Large scale maps
Small areas, is very detailed, a building is an area symbol
What is discrete phenomen?
phenomena with abrupt changes and gaps
What is continuous phenomena?
phenomena with smooth transitoins and no gaps
what are the levels of measurement?
constrained ratio - constrained to a tange
cyclical - cyclic data ratio scale
counts - integers with no fractions
fuzzy - categories
What is quantitative data?
Lightness
Color hue
perspective height
size
spacing
saturation
What is qualitative data?
Color hue
Shape
Arrangement
Orientation
Different types of maps
Choropleth
Isopleth
Dot maps
Proportional symbol maps
What is geographic scale?
Small scale is a small area
Large scale is a large area
What is cartographic scale?
Small scale is of a large area
Large scale is of a small area
1:50 000cm
give a definition for generalisation
the process of reducing information of maps due to a change in the map scale
Name 4 different tpyes of generalisation
Wrights 2 major components
Riazs 3 major components
Robinon et al
MacMasters and Sheas model of generalisation
Give examples of ways to generalise
Simplify
Smoothing
Aggregatino
Amalgamation
Refinig
Collapsing
Enhancing
Exageraing
Merging
Displacing
What are the different types of map projections?
Mercator
Robinsons
Goode homolosine
Mollweide
Mollweide oblique
plate caree
What are the classes of map projection?
PLanar
Cylindrical
Conical
What are the cases of map projections?
Tangent
Secant
What is another name for a tangent point and secant line?
Standard point and line
Where do lines of latitude run from?
Parallel with the equator. S
Where do lines of longitude run?
through the north and south pole E
what is DD?
Decimal degrees
How do we calculate SF?
local scale divided by principal scale
Tiscot’s Indicatrix circle
r=1
a=b=1
when a=b there is no distortion
when a=/b but a=1 then there is angular distortion
when a=b but a=/ 1 then aerial distortion takes place
when a=/b and a=/1 angular and aerial distortion occurs
What does UTM stand for?
Universal transverse mercator projection
List snyder’s heirarchy
- Region of world
- Projection property
- projection case
List snyder’s geographical areas
- World
- hemispher
- continent
How can we measure the earth’s surface if it is not smooth?
Turn it into a geoid by cutting off the “tallest” parts
then match the area of the geoid to an ellipsoid.
What is south africa”s geoidic datum?
Hartebeeshoek94 datum and Land Leveling datum
What kind of equivalent projections are there?
noninterrupted
interrupted
oblique aspect
why is spatial intellegence inportant?
essential for problem solving and orientating yourself in a new area
can examine problems from a spatial perspective
key characteristics of a map?
2D representation of a 3D object
uses maths to represent the earth onto 2D surface
has a reference system which allows the location of a feature to be described.
Give examples of thematic maps
Navigation charts
Cadastral maps and charts
Series maps
Web maps
Mental maps
Give an examples of geographic location questions
Where is it? Why is it here to there? HOw much is here or there?
Give examples of geographic distribution questions
Is it distributed locally or gloablly? Is it spatially clustred or dispersed?
Where are the boundaries?
Give examples of geographic association questions
What else is near it?
What else occurs in it?
What is absent in its presence?
Give examples of geographic interaction questions
is it linked to something else?
wha is the nature o this association?
how much interaction occurs between the locations?
Give examples of geagraphic change questions
Has it always been here?
How has it changed over time and space?
What causes its diffusion or contraction?
Why do we ask geographic questions?
fill in the gaps in our mental maps and in our geographic knowledge
What is the use of general-purpose maps?
shows inportant physical features in an area
summarise landscape to aid in discovery of locations
usually easy to read and understand
What is perception?
our initial reaction to map symbols
What is cognition?
perception plus our thoughts processes, prior experiences and memory.
Different types of memory
perception
short term visual store
long term visual memory
