By Muhammad SajjadPH# 03346544625

Contents

Definition

Explanation

Types

Requirements for modeling

Merits and demerits

References

Model in Geography

The world model is derived from French word “modele”, Italian word

“modello” and Latin word “modulus” means model.

Meanings of model

There are two meaning of model

1. Real or Original: It represents real things. For example; building,

car and aircraft and ship etc.

2. Ideal: It represents the ideal things. For example; ideal teacher,

ideal friend and ideal hero etc.

Definition of model

In 9465 Peter Haggett defined the model as, “a simplified version of

reality, built in order to demonstrate certain of the properties of

reality".

In French language it is defined as; “simplified representation with a

view to demonstration"

By Alain Rey, the model is a "system representing the essential

structures of a reality".

Explanation

After the reading of all these definitions it is right to say that

model is a simple representation of reality or it is also called analogy.

The models used in geography come from elsewhere. This is partly

true. So, others may have worked better and earlier than we have. It

is therefore intelligent and fruitful to take inspiration from their ideas

when these contribute to our understanding of the production of

geographical space.

This is not a reason to forget that geographers have produced an

abundance of their own models, which are no less useful: piedmont,

huerta, estuary region, frontier, march, dead ground, distribution

models of free ports and tax havens, and world megalopolises.

Furthermore, some imports and analogies are worth being re-

exported.

In the view, the gravity model (the bigger and the closer, the more

attractive) is infinitely easier to understand in geographical space

than in cosmic space, simply because, in everyday life we clearly

understand the reasons, i.e. the nature of the "energy" in question.

Modelers are dangerous, because their ambition is prediction and

application and they want to force reality to fit their models.

Apparently Christaller tried to persuade Hitler to "rectify" the

network of Polish towns to coincide with his model. Even if true—

and the anecdote needs to be verified—the undertaking did not

succeed.

At the same time, a plethora of territory-makers, neither

geographers nor scientists, have attempted, sometimes successfully,

to design or redesign spatial organizations to meet their

requirements. This has nothing to do with the idea of models, except

in the vulgar, prescriptive Sense of the word. This argument is simply

groundless accusation and is even comical in that it credits

geographers with powers they have never had.

Types of models

Ackoff (1962) differentiates between iconic models, which use the

same material but involve changes in scale, analogue models which

also involve a change in material used in building the model.

Symbolic models which represents the reality by some symbolic

system such as a system of mathematical equations. Each type of

model varies in its appropriateness for different functions. In next we

will study these types of models one by one.

Iconic models

This type of model shows three dimensional characters. For example

length, width and height of the feature that is photograph, map and

globe. They are simple represntator of reality

Analogy / Conceptual

When one phenomenon is represntated by other

phenomenon. Real things have become points on the Map. They are

abstraction and most models include in this group. These models are

use to represent the social conditions of a society in the form of

deferent concepts. For example; movies and dramas.

Symbolic models

The representation of a phenomenon or a situation with the

help of mathematical symbols is termed as mathematical models. In

this models different features and their relationship is shown in the

form of symbols.

Example

dN /dT=rn(1−¿N /k )¿

N= population size T= time period

K=max. Population size possible

r= growth rate

Requirements of models

Identity and identification

To define a geographical object, place, country, field or

distribution, is to describe its singularity or, in other words, its identity.

But how do we describe an identity and what does this word mean?

Identity comes from idem, the same. We define an identity by observing a

similarity. This is an interesting paradox, and a logical one: we can only

define something in reference to known models.

Tall, strong, blond, blue eyes, red skin, turned-up nose and round face are

elements of identification which, in sufficient number, will describe a

singular person. This description is based on a selection from among

general, common, inventoried, understood features.

Meaning.

To advance, these models must have meaning. Recognizing forms

implies that we understand where they come from and what produces

them. The subject is also complicated by phenomena of convergence:

identical forms can have different origins, and vice versa.

The geographer must at least make a conscious effort to recognize and

interpret spatial forms. This is the difference between science and

esoterism. The geomancer, astrologer or augur who "reads" coffee grinds,

a palm or a chicken’s innards observes forms whose origin bears no

relation to the question asked.

They are the only ones to "see" (or imagine), but they claim to have the

gift of trance and divine inspiration. Geographers, usually devoid of both,

use known forms, for which they have learned the logic of production

(whether of social or natural origin), even if they sometimes have to

discover new forms.

Merits

Models are more near to reality.

Brief description of a reality.

Models provide linkage between many physical features.

Models are pillars of research or theory.

Models help us to prepare the planning ahead.

De-merits

Simplest description of reality

Models have narrow impact of theories

Very hard to construct in very defined size

Data may not available of subject

References

HAGGETT P “Geography a Modern Synthesis” 3rd

revised Harper and row NEWYORK

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