Chapter 1 Thinking Geographically

Where we find Geography Geography exists in the global issues receiving attention at this time things such as… – Population growth – Terrorism – Cultural diffusion. Diffusion is defined as the spread of linguistic or cultural practices or innovations within a community or from one community to another.

Thinking Geographically In addition to political rule, boundaries can be drawn based on various components of culture including language, religion, values.

Every Story Can be approached from a Geographers Perspective Consider natural events and natural disasters. Do humans choose to live in harm’s way?

Spatial Definition Merriam Webster Dictionary: “Pattern of or relating to space and the relationship of objects within it.”

Spatial analysis Geography by its nature is a spatial science. Geographers therefore study space in order to locate the distribution of people and objects. Geographers ask two main questions, “where” and “why.” Spatial analysis is concerned with analyzing regularities achieved through interaction. Regularities result in a distinctive distribution of a feature. Distribution has three properties: – Density – Concentration – Pattern

US Land Ordinance of 1785 In addition to the global system of latitude and longitude, other mathematical indicators of locations are used in different parts of the world. In the US, the Land Ordinance of 1785 divided much of the country into a system of townships and ranges to facilitate the sale of land to settlers in the West.

A township is a square 6 miles on each side. Some of the north-south lines separating townships are called principal meridians and some east-west lines are designated base lines.

The Land Ordinance of 1785, coming on the heels of the Ordinance of 1784, was the effort of a five-person committee led by Thomas Jefferson. The ordinance established a systematic and ubiquitous process for surveying, planning and selling townships in the western frontier.

Each township has a number corresponding to its distance north or south of a particular base line. A second number, the range, corresponds to its distance east or west of a principal meridian.

Each section is divided into four quarter-sections. A quarter-section, which is 0.5 mile by 0.5 mile, or 160 acres, was the amount of land many western pioneers bought as a homestead.

How Geographers Address Location Maps – Early mapmaking Contemporary Tools – GIS (Geographic Information System) – Remote sensing (acquisition of data about Earth’s surface from a satellite) – GPS (Global Positioning System) – Projection (Scientific method of transferring locations on Earth’s surface to a flat map)

Early Mapmaking Earliest surviving maps were drawn by Babylonians on clay tablets about 2300 B.C.E.

Polynesians navigated for thousands of years with three dimensional maps (“Stick Charts”) Mediterranean sailors and traders made maps of rock formation, islands, and ocean currents as early as 800 B.C.E. Mapmaking is undoubtedly older

Early Cartographers Aristotle( B.C.E.): The first to demonstrate the earth was spherical. Observed curved shadow of the earth on the moon during an eclipse and the fact that the visible groups of stars change as one travels north or south.

Eratosthenes( B.C.E.): The first person on record to use the word “geography,” calculated the circumference of the earth and correctly divided the world into five climatic regions.

Non-European After Ptolemy, little progress was made in Europe for 100s of years. Phei Hsiu (Fei Xiu), “father of Chinese cartography,” produced an elaborate map of China in 267 C.E. Muslim geographer al-Idrisi prepared a map in 1154 C.E. Ibn-Battutah ( ) wrote Rihlah (Travels) based on 30 years of journeys, and over 74,500 c. miles

Projection The method of transferring location on Earth’s surface to a flat map is called projection. Earth’s spherical shape poses a challenge for cartographers because drawing Earth on a flat surface unavoidably produces distortion.

Distortion Four types of distortion – Shape – Distance – Relative size – Direction between points

Examples of Map Projections Robinson Projection Azimuthal Projection Goode’s Interrupted Projection

Contemporary Tools GIS A geographic information system (GIS) is a high-performance computer system that processes geographic data. Each type of information (topography, political boundaries, population density, manufacturing, etc.) is stored as an information layer. GIS is most powerful when it is used to combine several layers, to show relations.

Layers of a GIS Fig. 1-5: A geographic information system (GIS) stores information about a location in several layers. Each layer represents a different category of information.

GPS