What are contours?
Marjorie Henry, Contributor

Greetings to you all! It is a new year undoubtedly filled with opportunities for you to pursue your goals. Based on the thought I shared with you at the start of the current series of lessons in last September, I hope you do have the arrows in your bow as you aim for your goals. May this be a prosperous and productive year for you in all spheres of your life. May good health be yours as you pursue your preparations for the external examinations. Yes, these examinations must be brought into the picture now since you will begin to write them in approximately 14 weeks. That is certainly not far away.

So, the holidays came and went. How was it for you? I trust it was not all fun and frolic but that you did take my advice to spend some time doing some work as you prepare for the examinations later this year. In short, you should have taken time to review some lessons, research some topics and to complete your school-based assessments - among other things.

For several weeks in the last term I have been focusing on some practical skills that you must master, as outlined in the syllabus. These skills are tested in many ways and on all the papers that you write in the geography examinations. I hope you have been placing much emphasis on these skills also, and practising to perfect them for the examinations and beyond. Bear in mind that this is one question on the paper for which you can score maximum marks, once the skills are done accurately and properly. I will go on to another skill today, that of identifying landforms.

In reference to the syllabus, the specific objective 1.9 states that you should be able to:-

-Describe landforms through the reading of contours.

To discuss all the landforms in these lessons would be impossible. I will, therefore, discuss selected ones which are indicated on maps for the Caribbean territories.

My first question to you is this. What are contours? Just in case you do not know or have forgotten, these are level lines drawn on the map to show heights. Stated another way, these are lines on a map joining places of equal height above or below the sea level. Generally speaking, these lines are called isolines. Those drawn to depict the relief of the land are called isohypses. They are drawn at regular intervals on the map. By now you should be quite familiar with the Ordnance Survey maps on which these lines are drawn. The interval of these lines, known as the vertical intervals, is usually indicated in the key or legend of the map. It is important that you note this when reading your map.

The distance at which these lines are drawn from each other and the shape of them will inform you about the landforms they represent. When contour lines are drawn close to each other, these indicate the presence of a steep slope. On the other hand, when they are drawn far apart, these indicate a gentle slope. Sometimes the lines are drawn so closely to each other that they merge. The landform indicated by these merged lines is a cliff. Here are some examples seen on a map extract of Antigua. Observe places like Snapper Point and Charlotte Point.

This section of the map also shows contours closely drawn together at the same points named above, while the area easterly of The Ridge has the lines further apart from each other.

Let us now look at some landforms which are shown by the shape of the contours. A spur is a finger of highland jutting out into the lowland. The contours of a spur are similar to those for a valley. Both form a series of V-shaped lines but the difference for each feature is that for the spur, the apex of the V points to the low- land, while for the valley the apex points to the highland. These are shown in the following diagrams:

The V-shaped contours are evident. Look closely at the numbering of the contours to identify the location of the highland and the lowland.

The discussion on landforms will continue in the next lesson.

Marjorie Henry is an independent contributor. Send questions and comments to kerry-ann.hepburn@gleanerjm.com