Name: Understanding Thematic Maps
Uploaded: 2019-07-19
Duration: 5 min 6 s
Description: Master the art of displaying data visually in this lesson. Learn techniques to create clear, compelling graphs and charts to enhance your data interpretation skills.

Question

What is an Isopleth map? How an interpolation is carried out?

Accepted Answer

The term "Isopleth" is derived from the words "Iso," which means "equal," and "pleth," which means "lines." So, an isopleth is an imaginary line that connects places of equal value. Isotherm (equal temperature), Isobar (equal pressure), Isohyets (equal rainfall), Isonephs (equal cloudiness), Isohels (equal sunshine), contours (equal heights), Isobaths (equal depths), Isohaline (equal salinity), and other isopleths are commonly drawn. Interpolation is a technique for inserting intermediate values between the observed values of two stations/locations, such as the temperature recorded in Chennai and Hyderabad or the spot heights of two points.

Methods of Interpolation:

(i) Firstly, determine the minimum and maximum values given on the map.

(ii) Calculate the range of value, i.e. range $=$ maximum value $-$ minimum value.

(iii) Based on range, determine the interval in a whole number like $5, 10, 15,$ etc.

(iv) The exact point of drawing an isopleth is determined by using the following formula

$Point of Isopleth = \frac{Distance between two points in cm}{Difference between the two values of corresponding points} \times Interval$

What is an Isopleth map? How an interpolation is carried out?

Important Questions on Graphical Representation of Data

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