Question

Differentiate between choropleth and isopleths methods.

Answer 1

Sr. No.	Choropleth method	Isopleth method
1.	Different Geographical variables are represented by either a shade of the same colour or by different colours.	The data for the variable under study is demarcated by isolines, which are lines joining the places having the same value.
2.	Continuous or varying data can be used for mapping purposes.	Only continuous data is used.
3.	Administrative boundaries define data boundaries, and hence, continuous data may be misrepresented.	Administrative boundaries do not define a data boundary. The data boundary is defined by isolines.
4.	The smallest and largest values of the given data are used to classify the data range into acceptable classes.	Places having the same data value determine the drawing of isolines. The range is determined by the difference in these isolines.
5.	Colour gradient or patterns allow map interpretation; the deeper the colour, the higher the value of the data under study.	Placement of lines allows map interpretation; the closer the isolines, the steeper the data distribution.
6.	Mainly used for data like population density, distribution, etc.	Mainly used for continuous data like temperature, rainfall, altitude, etc.