Central place theory

It is normative deductive model postulated by Walther Christaller in 1933. It attempts to understand the settlement pattern observed in a region through a idealistic model as well as geometrical and functional analysis of settlements.

FUNDAMENTAL CONCEPTS

1. Principle of centralization:There is phenomenon of centralization in almost every aspect of existence like presence of nucleus in atom,presence of central sun in solar system,etc.
2. Principle of hierarchy:Phenomenon of development of hierarchy is a natural process and observed everywhere.Example stratification of society in classes,castes;presence of hierarchy in administrative system;solar system has hierarchy of planetary bodies like sun,planets and moons.

                               These principle seems to have universal presence and has been assumed by central place theory to exist in arrangement of settlements too.

DERIVATIVE CONCEPTS

1. Central Place: refers to settlement which forms focal point and has relations with surrounding smaller settlements in primarily, in terms of supply of goods and services which is not available in smaller settlements.
2. Complementary area: Its collection of smaller settlements around central place which is served by central place.Every central place is characterized by a complimentary area.
3. Central goods and services:  Goods and services provided by central place which is not available in complementary area.It can be of different order depending order of the settlement or central place.
4. Range of goods:  It refers to distance a person willing to walk to purchase it.This helps in determining complementary area.
5. Threshold:  refers to minimum no of customer willing to buy a good to making it commercially profitable enough to make available.
6. Centrality: is importance of central place as focal point which is determined by range of goods and services, no of people visiting and size of complementary area.

ASSUMPTIONS

1. Isotropic surface.
2. Rational and economic customers and sellers.
3. Population distribution and Income level throughout same.
4. Resource distribution same.
5. Hexagonal complimentary area: it is based on assumption that no section of population exist which is not served by any central place or served by more than two central place.Thus, there must neither be overlapping nor gap.Hexagonal shape serves the purpose.

THEORY

Following principle of hierarchy, there is development of different level of settlements varying in range of goods and services produced. Based on principle of centralisation,one settlement become central place for other smaller settlements which forms the complimentary area. Whole region is divided into complementary areas with a central place for each in nested pattern.

Same hierarchy

If all the settlement in one hierarchy is considered, than whole region can be divided into hexagonal complementary areas with the central place in centre.However,actual pattern is superimposition of such patterns existing at all levels.

Multiple hierarchies

When multiple settlement is considered then a nesting pattern of complementary areas emerge.Settlement of higher order is made up of combining complementary areas of lower hierarchy. How the complementary areas of lower hierarchy will combine to form complementary area of higher order settlement is decided by the nesting pattern.

Christaller has provided three nesting pattern based on different principle which are:

1. Marketing principle(K=3): Simple market needs leads to a nesting pattern where the complementary area of a central place is 3 times the complementary area of an immediate lower order settlement.

2. Transportation principle(K=4): connectivity leads to more reach and range of goods increased.Thus, here complementary area of a central place is 4 times the complementary area of immediate lower settlement.0

3. Administrative principal(K=7): Administrative services are compulsory in nature and has very high range leading to much larger complementary area.Thus, complementary area is 7 times the immediate lower one.