Some years ago, historian Ramachandra Guha opened a talk with these words: “Geography is about maps, history is about chaps.” It is quite an amusing statement. And very true. Maps are like rice and rasam to geographers! (Much tastier than bread and butter, I assure you!)
What graphs are to mathematics, maps are to geography. Here is another way of showing it: graphs : mathematics :: maps : geography. Graphs are visual representations of data, information. They are nowadays commonly called data visualizations. There are many many ways of showing data. Data visualizations are very clever and artistically beautiful – they involve both science and art.
When information is connected to location, it becomes geographic information. Geographic information is mappable.
Geographers use maps to convey geographic data in ways that are easier to understand than large tables. In doing this, they employ very complex statistics, mathematics, and art.
The art and science of making maps is called cartography.
Today, I share with you some examples of clever maps online that convey information in very fascinating ways.
My dear dear friend Professor Wiki-ji told me, over a cup of filter kaapi at the local darshini just the other day, “Dr Balachandran, old fruit … tell your young geographer friends: ‘A cartogram is a map in which some thematic mapping variable – such as travel time, population, or GNP – is substituted for land area or distance. The geometry or space of the map is distorted, sometimes extremely, in order to convey the information of this alternate variable. They are primarily used to display emphasis …’.”
I was utterly fascinated, as he always has something interesting to say. I got him another tumbler of the Drink of the Gods.
He sipped it, leaned forward, and with fire in his eyes, and great intensity, continued. “And, my dear old geographer, did you also know that there are two kinds of those … area cartograms and distance cartograms.” I said, “Really? You don’t say!”
He is a nice chap all in all, but not exactly quick to pick up sarcasm or jokes. He hissed, “I do say!”
I gave up.
“Do go on”, I said.
He did go on.
“You see, an area cartogram is usually used for showing population sizes of places. One does this by illustrating the relative sizes of the populations of the countries or provinces or other areas of the world by scaling the area of each country or province or other area in proportion to its population.”
“Yes, I have seen them …”
“Stop interrupting, man! You will make me lose my train of thought!”, he snapped.
“When we make a population cartogram, the sizes of the areas will change. But the positions and shapes are maintained as much as possible. Here look at this:
You see how much larger India and China are compared to the other countries? Their areas scaled to their population. Their shapes are only vaguely familiar. If your young geographers want to see the image online, tell them go here – they can zoom in and out and do other nakras, as these youngsters love to do these days!”
“Yes, I will, rāyarey!” Before he took off in great haste to some meeting, he showed me another cartogram. This one shows not population. It shows hectares under certified organic farming. He is a big organic farming nut. For the original of this, he says you should visit here.
Points from our conversation have been detailed here … or did the conversation come from there? Never mind!
You please go and find examples of distance cartograms if you would. Share your findings with me at firstname.lastname@example.org
Here is an interactive choropleth map (a map that shows how much of a particular kind of data there are in various areas). Here is an interactive choropleth map showing the life expectancy in various countries of the world: Examine these:
- What geographical patterns do you see on this map?
- Are certain kinds of countries better off than others?
- Are the better-off countries distributed around the world or are they in clusters in one or more parts of the world?
- What are some of the drawbacks of this kind of map that you can think of?
Then here is a choropleth map of the status of malaria in the world: From this map, and using your knowledge of biology, explore these questions:
- What latitude patterns do you see for the distribution of malaria?
- What factors might explain the above pattern?
- Why is the Sahara ‘non-malarious’?
Finally, check out the overall adult, male, and female obesity data here (being overweight to an extent that can be harmful to a person’s health): There are three different maps. Each can be animated to show data from 1975–2016. Observe the maps and compare them.
- How has obesity changed worldwide during 1975–2016?
- What might be some of the reasons for these changes?
- What are some of the consequences of increasing obesity?
Looking at all this, here is something you must realize. If you want great job security, become a cartographer! You will never be out of a job!
A version of this article appeared in the Deccan Herald Student Edition, 26 Sep. 2018
Featured image: World map of past and present status of malaria. (Source: https://goo.gl/HK6nUo ) [Accessed on 26 Sep. 2018]
A version of this article appeared in the Deccan Herald Student Edition, 19 September 2018
Featured image: World map of past and present status of malaria. (Source: https://goo.gl/HK6nUo)