GIS

Cartography

The Science or practice of drawing maps

What does the “Cartography” Acronym stand for? (Hint: There are only 5 parts to it)

C: Compromise

Art: an artistic expression of spatial info

O: Opportunity to communicate specific info

Graph: Communicating in a graphical way

Y: Why is this map being made?

What was the oldest map drawn on?

A mammoth tusk

Who first discovered that the earth was round?

The greeks in 350 BC

Who first calculated the earth’s circumference?

Eratosthenes in 250 BC used shadow length differences at the same time in two cities to determine the earth’s circumference.

Who created the first “realistic” maps?

Claudius Ptolemy

• Father of Geography

• Explained Lat. and Long.

• Developed projections

For Most of history realistic maps were the norm, true or false?

False

In ancient maps, what locations were often the focal point?

Mecca or Jerusalem

What are Portolan Charts?

Maritime maps developed for accurate sailing in the end of the middle ages

• incorporated compass bearings

• used a line network with ports labeled

What was waldseemuller’s map?

The first map to label america

Who was Ferdinand Magellan?

the first person to circumnavigate the world

What is a meridian?

A great circle which stretches from the north to the south Pole, creating longitudinal lines. They are all the same length

What is the Mercator projection?

the most common projection used today, drawn using rhumb lines or loxodromes

What are Rhumb lines or Loxodromes?

Lines which cross all meridians at the same angle on a map projection, a loxodromatic route appears straight on a map but is not the fastest route between two points

What is a great circle or Orthodromic route?

The shortest route between two points on a globe, which if drawn circumcentrally, splits the globe into two equal halves. Examples of great circles include the equator and meridians.

Before 1747 California was mistakenly depicted and referred to as…?

an island

What is GIS?

A geographic information system (GIS) is a computerized system designed for the storage, retrieval and analysis of geographically referenced data which are used to create maps.

What is a feature class?

a file with data about related geographic features

What is a map layer?

the actual presentation of a feature class on a map

What are some examples of Physical Map features?

Roads, rivers, lakes, parks, etc.

What are some examples of Political Map features?

States, provinces, municipalities, neighborhoods

What are some examples of Statistical features?

Census tracts (Or other choropleth map features)

What are some examples of administrative features?

schools, businesses, clinics, bus stops, etc.

What is vector data?

Discrete data composed of XY coordinates which is used to represent points, lines, or areas

What is raster data?

Continuous data which divides the world into square cells which contain an attribute value

What is the geodatabase?

a “container” used to hold a collection of GIS datasets

What does a qualitative map focus on?

Showing information about feature classes using symbols or colors (absence or presence of an object usually)

What does a quantitative map focus on?

Demonstrating numbers/stats (gradient usually)

What is a topographic map?

A map that shows natural and man-made features such as elevation, bodies of water, and roads

What is a navigational map?

A map used for navigation, called charts if nautical

What is the difference between a map and a chart?

Maps are of land bodies, charts are nautical

What is a cadastral map?

A map that shows legal boundaries of property and land ownership

What is a thematic map?

A map that Investigates a central subject (theme) in spatial context with other layers

What is a choropleth map?

a thematic map that is used to represent statistical data using the color mapping symbology technique

What is a numeric scale?

Process of placing data into groups (classes or bins) defined by break points

How many break points is it good for a numeric scale to have?

3-9 with 5-7 being the sweet spot

What are the six data classification methods?

• Equal Interval

• Quantile

• Natural Breaks (Jenks)

• Geometric

• Standard Deviation

• Manual

What is equal interval data classification, and what is it good for?

A method that Divides the range of attributes into equal sizes sub-ranges;

Good for presenting data to a non-technical audience

What is the quantile data classification method, and what is it good for?

A method in which Each class contains an equal number of features;

Good for evenly distributed data

What is the natural breaks data classification method, and what is it good for?

Data classification method in which Classes are based on natural groupings inherent in data, maximizes differences between classes;

Good for data that is not evenly distributed

What is the geographic data classification method and what is it good for?

A method which Creates class breaks based on intervals that have a geometric series thus Each class will have roughly the same number of values;

Good for continuous data that is not evenly distributed

What is the standard deviation data classification method?

A method which Highlights how much a feature’s attribute value varies from the mean

What is the manual data classification method and what is it good for?

Manual data classification can be decided using the histogram and is useful for a variety of fine tuning purposes

What is a histogram, where can you find it?

Provide information about the distribution of data Help to choose which data classification method is best;

Found by clicking symbology, choosing a type of symbology, and then clicking the histogram tab

What are some basic principles for map design?

• minimize ink

• Add contrast and value

• focus on important (figure) features and lessen focus on (ground) features

• Fonts and Halos are important

• Use simple solid shapes and exaggerate point sizes

What are some basic color related principles for map design?

• hue is basic color

• Value is lightness or darkness

• Saturation is the brilliance of a color

• Use muted colors

What are the three types of map scales?

• verbal

• Graphic

• Fractional

What is a small scale map?

A map with a larger ratio, ie. 1:100000000

What is a large scale map?

A map with a small scale ratio, eg. 1: 100

What is a map projection?

A Way to represent the curved surface of the earth on the flat surface of a map

What is a conical projection, what is it good for, what are its flaws?

• Well suited for long east-west regions

• Distortion constant along common parallels

• Distance toward the poles has the most distortion

What is a cylindrical projection, what is it good for, what are its flaws?

• Inflates the poles

• North is always up

What is a planar (azimuthal) projection, what is it good for, what are its flaws?

• Central projection point that intercepts the globe at varying angles

• Most common for polar regions

• Best suited for circular regions

What is a conformal projection?

a projection in which shapes stay the same; Parallels and meridians at right angles, Angles and shapes of small objects preserved

What is an Equal-area (Equivalent) projection?

a projection where areas stay the same; •Meridians and parallels are normally not at right angles, Often distorts distances and shapes

What is an equidistant projection?

a projection in which distances are correct; Preserves great circle distances, A distance can be held true from one (or a select few) point to all other points

What is an Azimuthal (true direction) projection?

a projection in which directions are accurate

• Preserves global directions

• Produces a circular map

• Centered on one point

• Often used for navigation

What are standard parallels?

lines at which there is no distortion

What is a compromise map projection?

A compromise map projection is a type of map projection that attempts to balance the distortions of size, shape, distance, and direction on a map. It aims to find a middle ground between preserving accurate representation of landmasses and minimizing distortions.

in map projections, _____ and ____ are mutually exclusive– preserving one will always distort the other.

Shape and area

What is a Geographic Coordinate System (GCS)?

a method of georeferencing (coordinates) which defines where the data is located on the earth’s surface

What is a Projected Coordinate system (PCS)?

A GCS and Map projection combined that tells the data how to draw on a flat surface, like on a paper map or a computer screen

What are cartesian coordinates?

X, Y coordinates

What are lines of latitude also called?

Parallels

What are lines of longitude also called?

meridians

On what levels can you look for Geographic data?

Local, state, national, international

What are some good places to find national geographic data?

The CDC website or the Bureau of Labor Stats website

What is remote sensing?

Process of deriving information by means of systems that are not in direct contact with the objects/phenomenon of interest

What is image processing?

Manipulating raw data produced by remote sensing systems

What is a polar orbit satellite?

A satellite that travels north to south in low orbit

what is a Sunsynchronous Orbit (SSO)?

a type of Polar Orbit which stays in sync with the sun, at the same ”fixed” position relative to the sun and covers the same place at the same time each day

What is a geostationary orbit (GSO)?

An orbit which Follows the equator at the same rate as Earth thus staying in a fixed place over time; useful for tellecommunication

What is landsat?

Longest running enterprise for satellite imagery of Earth

What is the current version of landsat?

Landsat 9?

What does landsat use to collect its data?

11 different color wavelength bands show different landsat data

What are some satellite brands other than landsat?

Maxar, quickbird, and sentinel

What are some ecological uses of landsat imagery?

• deforestation mapping

• ag. water use monitoring

• flood mitigation mapping

What is a Normalized Difference Vegetation Index (NDVI)?

an index which quantifies vegetation by measuring the difference between near infrared (which vegetation strongly reflects) and red light (which vegetation absorbs)

What range is an NDVI conducted on?

-1 to +1

What is the equation for an NDVI?

NDVI = (NIR - Red) / (NIR + Red)

In which NIR is Near infared

What data do you need to complete an NDVI?

Landsat Bands 4 and 5

If an NDVI is negative it is likely depicting what?

a body of water

If an NDVI is positive it is likely depicting what?

dense vegetation

How do you get data for an NDVI into GIS?

• Select an area of interest and Download bands 4 and 5 from USGS GloVis

• Filter for image quality (low cloud coverage)

• add the bands to your map!

How do you create a composite raster image for an NDVI in GIS?

• Use the Composite Bands tool (Geoprocessing Tool)

• Go to the Appearance tab- edit band combinations for Landsat Imagery (default is aerial imagery)

• Change Stretch Type

• Go to Analysis tab→ Raster functions→ NDVI

What is RADAR?

• Radio Detection and Ranging

• A Remote sensing method that relies on radio waves and can ”see through” vegetation to Produce clear images of land regardless of time of day

What is LIDAR?

• Light Detection and Ranging

• Form of remote sensing that uses laser beams to measure distance to Earth’s surface