Defining Spaces: Understanding regions and

boundariesDelaware Recommended Curriculum Regional Planning Course

Adapted by Maggie Legates, DGA from a presentation by P.W. Rees,

UD Department of Geography

a basic building block for geographyJust as a cell is to biology

a concept – a mental construct.

A region is

Why do people use regions?

What uses can you think of?

Defining regions Types of regions Defining boundaries Why are regions useful and important? How do planners use regional analysis

Outline of topics

Identify places with one or more similar characteristics

Circumscribe (draw a line around) the area of the earth’s surface occupied by those places!

To define (or establish) a region

an area of the earth’s surface that contains within it places with one or more similar characteristics

AND is separate from other areas that contain places with different characteristics

And you have made a region!

Easy to do!

Not so easy!

Place has to do with the qualities or attributes of a location

Region has to do with the area occupied

How is a region different from a place?

What characteristics is each classification system based on?

What kinds of data were used to generate this regionalization system?

Some examples of regional maps

Formal: defining characteristic is uniform across the entire area of the region

(Often the data is reported for the whole jurisdiction, so we can’t know the exact distribution)

Types of regions

Formal: defining characteristic is uniform across the entire area of the region

Functional (based on usage or function)

Types of regions

the defining characteristic is strongest in the center (“core”) and declines in intensity towards the edges (“periphery”)

Some examples:

With functional regions-

The core might not be at the center!

Marketing regions Service areas for businesses Metro areas Sports teams fan base

Other functional regions:

Formal: defining characteristic is uniform across the entire area of the region

Functional: defining characteristic is strongest in the center (“core”) and declines in intensity towards the edges (“periphery”)

Perceptual – based on personal beliefs – subjective rather than objective

Types of regions

A region cannot exist until its boundaries are defined.

Formal regions usually have definitive boundary lines. (What are the advantages and disadvantages of knowing where the line is?)

Defining boundaries

Do mountain peaks make good border markers?

How about rivers?

Lines of latitude have pros and cons too!

Over the years, the Rio Grande has changed frequently.

Does this make a good international border?

This map of Africa shows two types of boundaries:The red lines show tribal boundaries as they existed before European colonization. The black boundaries are modern national boundaries.What can be the result of many cultural groups within a country?

A region cannot exist until its boundaries are defined

Formal regions usually have definitive boundary lines.

Functional regions often have boundary zones◦ Core, ◦ Domain, ◦ Sphere

Defining boundaries

outlyers

Some methods of defining boundaries

◦ Identifying the core: orthogonal medians

◦ Identifying the periphery: Theissen polygons

Defining boundaries

Use this method when data is represented in dots.

Draw a line across the space at a place where half of the dots are above and half are below the line. Then draw a second line from top to bottom at a place where half of the dots are to the right and and half are left of the line.

The core of this region is at the intersection of the lines. The boundary can be established as a line around the outside.

Identifying the core: Finding orthogonal medians

Would this be a good way to pick a site for a new national capital?

Thiessen polygons- splitting the difference This method is used when locations or data

are represented by dots or points. On the dot map, mark a halfway point

between each dot and those surrounding it. Then connect the dots! The resulting

“regions” look strange, but they mark off the area that should be most convenient for travel to each center.

This method does NOT take into account road systems, barriers, or personal preferences.

Do large Thiessen areas guarantee a good fan base?

On this map, the Thiessen lines are drawn halfway between hospitals .The green circles symbolize populations using the hospitals.

Which Delaware hospital serves the least people?

Planners must be aware of requirements and boundaries of many types of regions.Consider this map of the public health district of Champaign-Urbana, Illinois!

Over lapping regional jurisdictions:City boundariesTownship boundariesFire protection districtsSanitary districtsMass transit districtsSchool districtsGrade school attendance areas

Regional analysis Used in business,

government, and non-profit sectors

Determining service areas Making comparisons Identifying departures from the norm Predicting trends Planning for the future

Regional analysis

Determining service areas Making comparisons Departures from the norm Anticipating change Promoting equity; exposing inequality

Regional analysis