Delineation of Region

Delineation of regions involves the grouping together of local units which have similar characteristics according to certain clearly defined criteria and which differ significantly from the units outside the region on the basis of certain chosen criteria. The criteria can be unemployment rates, activity rate, migration trends, per capita income etc. The characteristics should differ significantly from units outside the region. The methods of regional delineation involve

1) Fixed Index Method

Under the fixed index method, a number of characteristics common to regions are chosen (Eg. population, density, per capita income, unemployment, rate of industrialization). An arbitrary weight is given to each index and a single weighted mean is obtained for each region, then contiguous regions with similar indices are grouped together in order to minimize the variance within the group.

2) Variable Index Method

Under the variable index method, variable weights are assigned to highlight the different regions. The weight given to each activity, in each region is different, in accordance with the value or the volume regionally produced. For e.g., if region A is the wheat region and the region B is the coal region, the weight of the wheat index will be the largest in the former, and the weight of the coal index will be the largest in the latter. This method is good when those criteria can be compared with each other. However in those cases where compatibility is not possible (E.g., in case where one feature is literacy and the other is steel production) it becomes necessary to employ the cluster method

3) Cluster Method

Cluster means grouping together. This concept is used in the planning as a strategy to strengthen lateral links and to dissipate growing vertical links in the settlement system. Such a cluster while providing greater viability and threshold for development efforts will also create for themselves a greater bargaining power in bringing about reciprocity in exchange of goods and services. Both at the macro and micro level clustering can be done by superimposing of maps and by developing a composite index of development. This concept is used to implement IRDP (Integrated Rural Development Programme).

Methods for Delineation of Formal Regions

1) Weighted Index Number Method

In this method, some indices (parameters) are chosen and given weights, total weights for each part is separately calculated and areas with similar weights are carved out. This area is termed as ‘region’.

Example: To carve out a region of economic backwardness the parameters chosen were percentage of unemployment and per capita income. Then accordingly the weights were set up. It was decided that for every 1% of unemployment 2 weights shall be assigned and setting 1000 as the base for every 50 points below 1000, 1 weight shall be assigned. Hence more is the total weight more is the backwardness.

Weighted index number method

Suppose we consider a hypothetical area divided into 9 blocks having the given unemployment percentages and per capita income. If we then apply weights to each block as stated in the previous paragraph we will find that we can hatch an area with relatively more economic backwardness.

There are certain demerits of this method. To apply this method, the region must have proper delineated parts. This method can only be applied where quantifiable data is available and this method is not useful for delineating regions having natural/physiographic features.Similarly, you can use this method for employment and income level delineation.

  •     The study area is divided into several localities varying according to unemployment rates and per capita income levels.

  •      The aim is to isolate the main problem region; i.e. the area of economic malaise.

  •      Weights are assigned to each criteria and when taken together and weighted, one of the region can be isolated.

2) The Factor Analysis method

In this method, each parameter is mapped out separately and then all the maps are kept one over the other. The common region that will be carved out after this exercise will form a region.

Used for delineating economic health regions.

  •  Used for delineating economic health regions.

  •  Many of these criteria are interdependent. The factor analysis method can be       used to isolate these factors and to group areas on the basis of factor                   loadings.

  •  ‘Industrial change’ and ‘industrial structure’ are major industrial factors and          ‘population change’ and ‘social structure’ as major socio-economic factors.

  •   These factors help in delineating economic health regions.

Example: To carve out South eastern mineral region. The parameters considered were geology, minerals (coal, iron ore, bauxite and silica), availability of rail, soil, vegetation, climate and population. Each line depicts an aspect and is called girdle.

                        Example for factor analysis method

The area which satisfied 6 girdles was carved out and was called the South East mineral region. Sometimes some parts of the delineated area have administrative conflicts at those moments, adjustment is done on the basis of smallest unit of delineation method.

Methods for Delineation of Functional Regions

1) Flow Analysis Method

Flow analysis builds up functional regions on the basis of the direction and intensity of flows between the dominant centre and surrounding satellites. Each flow will show decreasing intensity as it becomes more distant from the main centre and increasing intensity as it approaches another centre. The boundary of the sphere of influence of the dominant centre will be where the flow intensity at a minimum. When the flow significantly drops that means interaction/origin’s influence drops. In terms of distance, in a particular direction, there is the influence of the node and there onwards it drops. This gives cut off points. 

Features of Flow Analysis Method

  •    Builds up flows on the basis of the direction and intensity flows between the dominant center and surrounding satellites.

  •    Flows may be of several types: economic (road, rail, shopping or commuting); social (such as flow of students or patients); political (flow of govt. expenditure); information (newspapers, telephone calls), etc.

  •   Graph theory: measures the relationship (economic, social, etc) between selected group of centers on the basis of flows between the centers. The no. of telephone calls is the usual flow criteria.

  •     The flows are plotted in matrix form, from which primary and secondary flows into and out of each center can be identified.

Illustrative Example Using Flow Analysis Method

 Example using flow analysis method

The no. of telephone calls is taken as the flow criteria. The flows are plotted in matrix form, from which the primary and secondary flows into and out of each centre can be identified. The resulting hierarchy of nodes can plotted as a simple network, providing an insight into the form and extent of functional relationships within an area. Here D is the major centre, with B,E and G subsidiary centres.

2) Gravitational Analysis Method

It is concerned with the theoretical forces of attraction between centres rather than actual flows. The gravity model assumes that the interaction between two centres is directly proportional to the ‘mass’ of the centres and inversely proportional to ‘distance’ between the centres.

·         ‘Mass’ can be population, employment, income, expenditure and retail turnover.

·         Distance can be in physical terms (km), time, price, and intervening opportunities.

·         In mathematical notation

f = k (m1 m2)/d

Where f is the force of attraction between two settlements, m1 and m2 are masses of the two settlements and d is the distance between them. K is a constant.



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