Introduction to Cartography F Maps vs Globes F

Introduction to Cartography F Maps vs. Globes F General Types of Maps F Standard Map Features F Map Projections F GIS F GPS F Remote Sensing F Representation in Maps or “How to Lie with Maps”

Maps versus Globes F Map: a representation of the world or part of it, in two dimensions F Globe: a 3 -D representation of the entire earth surface. What are some advantages and disadvantages of each?

Map Projections F Mathematical method for systematically transforming a 3 -D earth into a 2 -D map. F Three traditional types: – cyllindrical – conical – planar (azimuthal-zenithal) F Newer Mathematical Projections – Robinson

Cartographer’s Dilemma F All maps introduce distortion: – shape (conformance) – size (equivalence) – direction – distance F Maps can be either equivalent or conformal, but cannot emphasize both characteristics.

Introduction to Cartography F Maps vs. Globes F General Types of Maps F Standard Map Features F Map Projections F Representation in Maps or “How to Lie with Maps”

General Types of Maps General Purpose and Topographic Depict the form and relief of the surface and/or general features, such as roads, buildings, and political boundaries. Thematic These maps represent the spatial dimensions of particular phenomenon (themes).

Thematic Maps These maps represent the spatial dimensions of a particular phenomenon (theme). Types: u Isopleth maps - isolines connect points of equal magnitude. u Choropleth map - tonal shadings are graduated to represent areal variations in number or density within a region, usually a formal region.

Introduction to Cartography F Maps vs. Globes F General Types of Maps F Standard Map Features F Map Projections F Representation in Maps or “How to Lie with Maps”

Map Scale relates distance on map to distance on earth, thus smaller scale represents larger area. F Small Scale – shows large area – 1: 10, 000 would represent about 1/2 of U. S. on single page of paper. F Large Scale – shows small area – 1: 63, 360 would represent a small town on a single page of paper. What is the largest scale map possible?

Map Scale - 3 Types

Orientation or Direction F North arrow or Compass Rose F European maps of the dark ages, prior to European acceptance (1500’s) of the magnetic compass, were ‘oriented to the east. ’ After compass it made more sense to place north at the top during use. N

Grid North = very close to true north. Used to place grids on maps for archaeology, mines, artillery targeting.

Mercator’s Navigation Technique Gnomonic Projection shows great circles as straight line. Mercator Projection shows constant compass headings (azimuth) as straight lines. Rhumb Lines

What is GIS? F Stands for "geographic information systems" F Definition: a system for the input, storage, manipulation, and output of geographic data – a specialized "information system” u information systems are used to work with (manipulate, summarize, query, edit, visualize) information stored in computer databases – utilizes spatial indexing of information to track what is where on the Earth's surface

Elements of a Geographic Information System (GIS) F Database with spatially-coded data (latitude/longitude) F Computer F GIS Application Software (Arc. View, Arc. Info, Map. Info) F Video Map Display F Scanners F Digitizer F Plotter/Printer

Functions of a Geographic Information System F Site selection F Find density within an area F Catalogue and track spatial data – Land use maps, for example F Network Functions – Street grid navigation – Municipal water supplies, sewers – Hydrology (rivers, streams, lakes) F Consumer Tracking and Marketing

Examples of Geographic Information Systems F Google Maps F Google Earth F Zillow. com F National Atlas of the United States

Natural Resource GIS

High Quality Map Display

GPS

GPS and GIS are increasingly integrated.

Remote Sensing F Digital Remote Sensing – Multispectral Sensors – visible, radar, infrared, ultraviolet – Digital Image Manipulation – Direct download into GIS systems

Photographic Remote Sensing - aerial photos - camera mounted on airplane takes visible light photographs - infrared film - sensitive to red end of the light spectrum (crops and plants)

Las Vegas, 1972 - infrared LANDSAT

Las Vegas, 1992 - infrared LANDSAT

How to Lie with Maps F Misrepresentation - Propaganda Maps F Selection of Map Features F Orientation F The Authoritative Power of Maps