The document discusses various scientific methods used to delineate and classify regions for planning purposes. It describes flow analysis, gravitational analysis, Thiessen polygon method, distance minimization method, and discriminant analysis method. Flow analysis involves analyzing the direction and intensity of flows between centers and surrounding areas to determine functional regions. Gravitational analysis uses a gravity model to measure interaction between centers based on their mass and distance. The Thiessen polygon method divides an area into polygons around sampling points. The distance minimization method aims to minimize transportation costs. Discriminant analysis groups regions based on similar variable characteristics. In summary, the document outlines different analytical techniques for defining and categorizing regions scientifically for regional and urban planning.

1. Regional & Metropolitan Planning
Dr. Mohammed Firoz . C
Architect and Urbanist
Department of Architecture and Planning
National Institute of Technology Calicut, India
Lecture 8

2. Lecture : Delineation of regions

3. Classification of Regions
No fixed
boundary
-social
acceptan
ce
District or
state
regionalizat
ion
technique,
Summary of Regions classifications

4. Methods of Delineation of Formal Region
1. Factor analysis methods ( Complex
methods)
2 Weighted index number methods (
Relatively simple methods)
i. Single Index method
Ii Fixed Index Method
iii Variable Index Method
3 Cluster Method
.
Methods of Delineation of
Functional Region
1. Flow Analysis
2. Gravitational Analysis
Methods
Methods of Delineation of Planning
Regions •
1. Theissen Polygon Method
2. Distance Minimization Method
3. Discrimint Analysis Method
4. Graph Theory Method
Methods of Delineation of Regions
Scientific Methods of Delineation of Regions

5. • Flow analysis builds up functional regions on the basis of the direction
and intensity of flows between the dominant center and surrounding
satellites.
• Each flow will show decreasing intensity as it becomes more distant
from the main center and increasing intensity as it approaches another
center.
• The influence is highest at the center / node and decreases as and when
moved away from the node
• The boundary of the sphere of influence of the dominant center will be
where the flow intensity at a minimum and the influence further drops
nearing to zero
• This gives cut off points ( on influence of influence ) and finally the
tentative delineation is done.
Flow analysis

6. Flow analysis
City
Input/Output
region
Zone of Influence
tends to Zero
Boundary of City
region ends here

7. • Flows may be of several types:
• economic (road, rail, shopping or commuting-cargo or passenger );
• social (such as flow of students or patients);
• political (flow of govt. expenditure);
• information (newspapers, telephone calls), etc.
• The flows are plotted in matrix form, from which primary and
secondary flows into and out of each center can be identified
Flow analysis
Dominant
Service
center
Surrounding
Satellite Area
Surrounding
Satellite Area
Surrounding
Satellite Area
Surrounding
Satellite Area
Surrounding
Satellite Area
Surrounding
Satellite Area

8. Flow analysis
No of Commutations per day (in 1000’s
No of Telephone calls per day (in
1000’s)
No
of
Commutations
per
day
(in
1000’s
No
fo
Telephone
calls
per
day
(in
1000’s)
A B
10
40

9. • The gravity model assumes that the interaction between two
center's is directly proportional to the ‘mass’ of the centres and
inversely proportional to ‘distance’ between the centres
o ‘Mass’ can be population, employment, income, expenditure and retail
turnover.
o Distance can be in physical terms (kms) including air distance , time, price,
and intervening opportunities.
o In mathematical notation f = k (m1 * m2)/d2
( K= Constant, m1, m2 Mass, d=distance)
Gravitational analysis
City 1
v1
V2
V3
Eg:
Force of Spending of village 1 on City 1
Decreases as distance increases
Join an imaginary line connecting all
villages /satellites surrounding the city
based on the force of attraction

10. Gravitational analysis
https://www.youtube.com/watch?v=qSELZJ-RhCM

11. Used in land use planning or rain fall pattern identification etc
The Thiessen polygon method was used by Bogue in 1949, to demarcate 67
metropolitan territories in the United States. The construction of polygons done in 6
steps –
• The connecting lines are drawn from the each adjacent center to another nearest
center.
• The midpoints of the lines draw from bisection lines connecting to the centers.
• From the middle point, a vertical line is drawn on which the line is a ground of
polygons. Similarly, lines are drawn from other midpoints.
• Units located across the boundary lines are included within the boundary of that
center. In which more than half the area of that unit is located.
• Once the polygons are formed, each area of the polygon is multiplied with the
value associated ( say average rainfall etc)
• All values are summed and divided by total area
Thiesson polygon
• Though widely used, this method has its shortcomings. For example, in
mountainous areas, an irregular spatial distribution of precipitation can be formed
over small distances, and the Thiessen method can yield erroneous results.
• More accurate methods are used sometimes ,say using Arc GIS etc

12. Thiesson polygon
Watershed boundary with Rain gauge stations

13. Thiesson polygon
Constructing polygons by connecting the bisected lines

14. Thiesson polygon
Calculate Area of the Polygon with respect to each Quantity of
Presipitations

15. Thiesson polygon
Average Precipitation in total and wrt to each polygon

16. Video Theisen Polygon construction TUTORIAL
https://www.youtube.com/watch?v=3xPAm432yV8
https://www.youtube.com/watch?v=YbzD8kZA-AE
https://www.youtube.com/watch?v=dpCQ2t1QoVM&t=
7s
https://www.youtube.com/watch?v=J4IdUVbJgj4&t=1s
https://www.youtube.com/watch?v=17IaRyzS79o
Video Theisen Polygon construction in Arc GIS
https://www.youtube.com/watch?v=BPjScQ-fovU
Thiesson polygon

17. • In this method minimizing the distance by the cost of transportation for
transporting an object from its various sources to several destinations or
transporting it back from the destination to the source has to be
minimized.
• In 1963, an experiment was conducted on 2900 students attending 13
high schools in Wisconsin State Grand County. The optimum limit of
school areas was determined in such a way
• Possible to minimize travel distance and determine which student can go
to which school with minimum hindrance wrt to travel time, and other
constraints. Accordingly, each school, pupils etc can be optimised
• With advent of operation research methods ( Optimization techniques) ,
and software's, such tasks are simpler and easier
• Alternatively, Airline scheduling exercise ( Destinations as airports
instead of schools, Passengers instead of students)
Distance minimization method

18. • A method to group regions, settlments etc based on the nature of
variables they represent ( similar to factor analysis and cluster analysis)
Discriminant analysis method

19. Summary
Delineating a region for planning is a complex task. There is no hard and
fast rule to delineate regions, except for the logic and discretion of the
researcher taking into account of the site, context and conditions

20. Summary
Thank You