Graphical Representation of Data 

Chapter 3

1 . Choose the right answer from the four alternatives given below:

(i) Which one of the following map shows the population distribution:

(a) Choropleth maps         (b) Isopleth maps

(c) Dot maps                       (d) Square root maps

Ans: (a) Choropleth maps 

(ii) Which one of the following is best suited to represent the decadal growth of population?

(a) Line graph                 (b) Bar diagram

(c) Circle diagram           (d) Flow diagram

Ans: (a) Line graph   

(iii) Polygraph is constructed to represent:

(a) Only one variable                      (b) Two variables only
(c) More than two variables           (d) None of the above

Ans: (c) More than two variables.  

(iv) Which one of the following maps is known as “Dynamic Map”?

(a) Dot map                 (b) Choropleth
(c) Isopleth                   (d) Flow map

Ans: (d) Flow map.


2. Answer the following questions in about 30 words:

(i) What is a thematic map?

Ans: A thematic map zooms in on a specific theme or topic, like rainfall patterns, population density, or earthquake zones. It uses colors, patterns, or symbols to highlight the theme's distribution across a geographical area, revealing hidden patterns and trends. Think of it as a regular map wearing a specialized lens!

(ii) Differentiate between multiple bar diagram and compound bar  diagram.

Ans:  Both show multiple variables, but:

*Multiple bar diagram: Each variable gets its own separate bar for each category. Imagine comparing apples and oranges with two sets of bars, one for each fruit.

*Compound bar diagram: Each category gets one stacked bar, with each segment within the bar representing a different variable. Think of layering apple and orange slices on top of each other for each location.
In short, multiple bars = side-by-side comparison, compound bars = layered comparison within categories.

(iii) What are the requirements to construct a dot map?

Ans: To build a dot map, you need:

*A map of the area: Your canvas – defines spatial location.

*Data for your theme: Points of interest, like population or resource locations.

*Scale for dots: Each dot represents a fixed value (e.g., 1 dot = 100 people).

*Clarity: Don't overcrowd! Choose appropriate dot size and spacing for readability.

With these tools, you can paint a picture of your data's spatial distribution across your chosen area.

(iv) Describe the method of constructing a traffic flow map.

Ans: Traffic flow maps involve:

1. Data sourcing: Gather traffic volume data from sensors, GPS, or road surveys.

2. Categorization: Classify traffic volume levels (low, medium, high) for clear representation.

3. Flow lines: Draw lines between origin and destination points, with thickness proportional to traffic volume.

4. Color coding: Use color gradients to visually indicate varying traffic intensities.

5. Annotation: Add labels for key locations, road names, and traffic volume ranges.

    It's like painting a picture of the city's pulse, revealing where the roads buzz and where they crawl.

(v) What is an Isopleth map ? How an interpolation is carried out?

Ans:  An isopleth map connects points with equal values of a specific variable, like temperature or pressure, using smooth lines called isopleths. Imagine it as a contour map for data, like altitude for mountains.

Interpolation fills in the gaps between known data points. Methods include:

*Nearest neighbor: Assign the value of the closest known point.

*Linear interpolation: Calculate a weighted average of nearby points.

*Kriging: Use sophisticated statistical models to estimate values based on spatial relationships.

These methods help paint a complete picture of the variable's distribution even with limited data points.

(vi) Describe and illustrate important steps to be followed in preparing a choropleth map.

Ans:  Choropleth Map: A Step-by-Step Blueprint

1. Gather Data: Choose a region and variable (population density, income levels, etc.). Ensure data aligns with your chosen map projection.

2. Classify Values: Divide your data range into meaningful categories (5-8 is ideal). Consider equal intervals, quantiles, or natural breaks based on data distribution.

3. Color Scheme: Select a color palette that is visually appealing and accurately reflects your data categories. Avoid misleading color gradients!

4. Map Preparation: Choose a base map with clear boundaries and appropriate thematic features. Ensure data units and map projection are compatible.

5. Symbolize Regions: Assign each category a corresponding color from your chosen palette. Label categories and legends clearly.

6. Refine and Polish: Add title, legend, scale bar, and any additional context like reference maps or annotations. Check for visual clarity and accuracy.

    Remember, a good choropleth map tells a story through color and geography. Make it clear, informative, and visually engaging!

(vii) Discuss important steps to represent data with help of a pie- diagram

Ans:  Pie-ing Together a Delicious Data Story:

1. Slice it Right: Categorize your data into meaningful portions. Aim for 5-8 slices for clarity.

2. Calculate Portions: Assign each category a percentage based on its contribution to the whole. 360 degrees = 100%!

3. Bake the Pie: Draw a circle and divide it into sectors proportional to each category's percentage.

4. Color Code Wisely: Choose distinct, contrasting colors for each slice to enhance readability.

5. Label with Love: Add clear labels to each slice, showing category and corresponding percentage.

6. Slice of Wisdom: Include a legend explaining color choices and data values.

7. Sweeten the Deal: Consider a title and overall presentation that complements your delicious data pie!

    Remember, a good pie chart is like a satisfying dessert: clear, concise, and visually appealing. So, bake with care and let your data shine!

Activity 

1. Represent the following data with the help of suitable diagram.

India : Trends of Urbanisation 1901-2001





2 . Represent the following data with the help of suitable diagram.


India : Literacy and Enrolment Ratio in Primary and Upper Primary School




3 . Represent the following data with help of pie-diagram. 

India : Land use 1951-2001


4 . Study the table given below and draw the given diagrams/maps. 

Area and Production of Rice in major States



 (a) Construct a multiple bar diagram to show area under rice in each State.
(b) Construct a pie-diagram to show the percentage of area under rice in each State.
(c) Construct a dot map to show the production of rice in each State.
(d) Construct a Choropleth map to show the percentage of production of rice in States.
5. Show the following data of temperature and rainfall of Kolkata with a suitable diagram.




Question and Answer Type By: Himashree Bora.