Choropleths are maps on which information is presented using a colour-coded system.
BANGLADESH INDIA ACTIVITY SRI LANKA
Examine Fig. 23. (a) How many hours after the earthquake did the tsunami reach: (i) Sri Lanka? (ii) Somalia?
(b) What was the height of the wave at these two locations?
SOMALIA MALDIVES
KENYA TANZANIA
MALAYSIA INDONESIA
SEYCHELLES Epicentre
0.2 – 0.4 m Wave height
0.4 – 0.6 m 0.6 – 0.8 m 0.8 – 1.0 m 1.0 – 2.0 m 2.0 – 17.0 m
Arrival time of tsunami BURMA THAILAND CHOROPLETHS
Fig. 23 The area affected by the tsunami that hit South-East Asia, December 2004
13.4 Drawing graphs for the Leaving Certificate Exam
To draw a graph representing data from a table, follow the guidelines given below. These guidelines are based on the Leaving Certificate marking scheme.
1. Always put a title on your graph. The title can be copied from the title on the data table given in the question.
2. Always use graph paper. There are often marks awarded for the use of graph paper. Ask the exam supervisor for this paper.
3. If drawing a bar or trend graph, make sure the axes of your graph are drawn with a ruler and labelled. Ensure that the scale is carefully shown. If drawing a pie chart, use a compass to draw the circle and carefully mark the centre.
4. Accurately show the information from the data table using bars/points/sectors.
5. There are often marks available for overall presentation. Neatness gets you marks! Use colour wisely. Do not scribble with biro to colour a bar or pie sector.
Which graph to use? 1. Trend graphs show changes over time. 2. Bar charts, graphs and pie charts show comparisons or single sets of data.
3. Pie charts are more time consuming to draw, so use a bar chart instead unless specifically asked for a pie chart.