Visualising Indian Elections

When the Election Commission res­ults for the 2011 as­sembly elec­tions came out, we thought we’d take a look at the res­ults for Tamil Nadu.

The easi­est way to see geo­graph­ic data is, of course, on a map. Since the res­ults are an­nounced constituency-wise, it makes lo­gic­al sense to plot each con­stitu­ency on the map.

However, map-based visu­al­isa­tions suf­fer from one prob­lem: the area of a geo­graph­ic re­gion is not al­ways pro­por­tion­al to its im­port­ance. In elec­tions, each con­stitu­ency equal weight­age: one seat. But the areas can vary con­sid­er­ably. Chennai, for in­stance, is a tiny dot on the map, but yet is split in­to three dif­fer­ent con­stitu­en­cies.

A bet­ter way is to take an ap­prox­im­a­tion of the map. We can plot each con­stitu­ency as a block, and po­s­i­tion it roughly at its geo­graph­ic loc­a­tion, and roughly pre­serve ad­ja­cency. This gives a reas­on­ably good geo­graph­ic pic­ture, while show­ing re­l­at­ive im­port­ance ac­cur­ately.

For ex­ample, here is a world map: the area is pro­por­tion­al to each country’s pop­u­la­tion.


We did the same for Tamil Nadu. Below is an in­ter­act­ive map that shows voter turnout. Hovering over each cell will show the num­ber of voters that turned out in that con­stitu­ency. Black shows higher votes, white shows few­er voters.

Voter turnout

Men turnout

Women turnout

The num­ber of the re­gistered voters ranges from 140,000 (Kilvelur) to 360,000 (Shozhinganallur). Each box rep­res­ents one con­stitu­ency, with a po­s­i­tion ap­prox­im­at­ing its geo­graph­ic loc­a­tion. This is a reas­on­ably good proxy for a con­stitu­ency dens­ity map.

Now, let’s take a look at voter turnout.


Turnout% men

Turnout% women

The voter turnout was pretty high, at 78%. Not too dif­fer­ent between the men (77.7%) and wo­men (78.5%), but quite dif­fer­ent across con­stitu­en­cies. Palacodu, Kulithalai and Veerapandi led the pack with turnouts of 87%, 89% and 89% while Chennai Harbour, Killiyoor and Colachal bot­tom at 64% each. The lowest turnouts are con­cen­trated around Chennai, Coimbatore and Kanyakumari – in­ter­est­ingly these are the more af­flu­ent areas.

% votes: ADMK

% votes: DMDK

% votes: DMK

Clearly, ADMK has swept the elec­tions. What’s in­ter­est­ing is that they won ab­so­lute ma­jor­it­ies in a num­ber of areas (high­lighted by the dark­er shades of green), un­like DMK or MDMK, who mostly won sim­ple ma­jor­it­ies.

% margin: ADMK

% margin: DMDK

% margin: DMK

A num­ber of ADMK vic­tor­ies were by a large mar­gin, but so were some of the DMDK and DMK vic­tor­ies. AKT Raja of DMDK won Thirupurankundram with a 30% mar­gin, for ex­ample. Former Chief Minister M. Karunanidhi (DMK) won with a com­fort­able 29% mar­gin at Thiruvarur as well. Vijaykant (DMDK) man­aged an 18% mar­gin at Rishivandiyam. It is in­ter­est­ing that 92% wo­men voted at Rishivandiyam – sig­ni­fic­antly higher than any­where else in the state.

2 thoughts on “Visualising Indian Elections”

  1. Excellent blog! One ques­tion re­gard­ing these maps: is it pos­sible to cre­ate a map for the 403 as­sembly con­stitu­en­cies in UP? Thank you.

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