Region

• It is a distinctive unit or area based on the interaction of small spatial & ecological system over the space. It has particular characteristics such as physical condition or economic organisations which affects the spatial relationship that man has with the space.
• Region refers to a unit of space where homogeneity increases inwards & heterogeneity across the boundary.  A region is a segment of a landscape presenting a coherent picture of a set of attributes. eg. Savana region has unique vegetation which presents that coherent picture. Thus region have uniqueness & distinctiveness from the surroundings.
• A region can be defined as a homogeneous area where a set of criteria applies.
• Regionalisation is the process of delineating surface of earth but each time guided by a purpose. Thus regions have purpose or goal.
• Regionalisation deals with the differentiation of political measure in space. If such political regionalisation coincides with physical homogeneity, it becomes a unit of regional planning.
• Regions have transitional boundaries because the phenomena continues to exist, but may not be with the same magnitude.
• Regions are mental construct & they are anthropogenic because nature doesn't have classification, and regionalisation is an achedmic endeavour to reduce the complexity of the phenomena.
• Region is distinct from area. Area is merely a space unit while region is area+phenomena. Phenomena is an event of a thing by itself.
• Region and space are also distinct because space is framework where phenomena exist.

Classification of Region

(i)Formal Based on uniformity given by a particular region

(ii)Functional It has defined core that retain a specific characteristic that diminishes outwards.

(iii)Programming Which is designed to serve a particular purpose.

Formal Region

• They are non-dynamic & subjective regions where the criteria taken are abstract. eg. cultural region.
• Such regions have transitional boundary and they are perception based. eg. Malyalam cultural region, Bengali cultural region(criteria is language, lifestyle, etc.)
• Linguistic regions are formal regions. Geographical region or paleo-geographical region is also formal region.

Functional Region

• They are objective regions; criteria is quantitative. They have flow pattern. They are dynamic. Boundaries are not fixed but they have linear boundary.
• Industrial regions are functional region. Metropolitian region, city region, administrative region are also functional region.

The methods for Delimitation of Boundary

1.  Mono-variable Method/Single Index Method
   • It is used for demarcation of formal region.
   • It is uses a single creatia for differentiation of two units of the landscape. eg. for demarcation of backward region, per capita income can be taken as criteria.
   • If Y_a – Y_b = 0, regionalisation or demarcation of region can't take place. Here, a & b are subunits and Y is per capita income.
   • But if Y_a – Y_b = k, is a fixed criteria adopted by policy maker. But it can only provide with the transitional boundary.
2. The Flow Analysis
   • It is used for demarcation of the functional region. eg. Industrial region.
   • The inflow of raw material, labour, capital and outflow of products can be demarcated on the basis of transportation lines & all the port lines are joined by vertical lines. Thus, it gives the star diagram.

Problems in Demarcation

1. Definition of regional boundaries
   • Physical features does not change abruptly as the lines on map.
2. Scale
   • Depending upon the criteria used,  there are thousands of regions that can be defined, ranging from the environmental region to region served by a single shop.

Demarcation of city regions or Denoted regions

1. Qualitative Methods
   1. R. L. Singh's Method
   2. UN method
   3. Skyline Method
2. Quantitative Method
   1. Gravity Model
   2. Break point Model
   3. Law of retail gravitation