Calculation of gradients, using ratio II
Marjorie Henry, Contributor

A student of Bridgeport High School shows off one of his pieces for the 'Youthlink' camera. Pride in your work is one of the first ingredients for success. - Anthony Minott/ Freelance Photographer

The map-reading skill discussed in the last lesson was that of giving angular bearing. In reference to the map extract of a section of Basseterre, I gave you two exercises on this skill. Here are the answers:

(i) Is the bearing from trig station K12 to trig station K48 71?.

(ii) Is the bearing from trig station K9 to the Church at Pond Estate 230?

You may not have the exact answers but there should not be much variation from these. You are allowed a variation of plus or minus 1 in your answer.

In reference to the question being discussed, that is, question 1 of the recent examination, this part of the question on bearing is the last to test practical skills. You may recall that in an earlier lesson in the current series, I had highlighted the fact that the questions are all structured on a three-profile dimension. These are: profile 1 - practical skills; profile 2 - knowledge and comprehension; profile 3 - use of knowledge. In question 1, sub-sections (a) to (f) were testing practical skills. It was not possible to discuss all aspects of profile 1, however, I would like you to know that if you were able to do all of profile 1 correctly, you would have realised 50 per cent of the total marks for the question. Achieving full marks for this section of the question is not impossible. Once you have grasped the concepts, keep practising them.

Sub-sections (g) and (h) represent profile 2. In these sub-sections, you are asked to do some DESCRIPTION. Let us look at each question beginning with (g).

Give a brief description of the distribution of sugar cane and forests over the area shown in the map.

This is testing description of vegetation. It specifically refers to sugar cane - a cultivated crop and forest - natural vegetation. Description of vegetation is a requirement of the syllabus. To do this in map reading, you MUST study the map extract carefully. Use the legend/key of the map to guide you in identifying the vegetation shown on the map.

Generally speaking, there are some key questions to be asked when describing vegetation. Let me share them with you.

(a) What is the nature of the vegetation?

Be able to distinguish between natural vegetation and cultivated crops. Cultivated crops refer to crops deliberately planted by man, for example, sugar cane, citrus and coconut. Natural vegetation refers to plants which grow in response to climate, relief and other natural factors and include woodland, trees, scrub and mangrove.

(b) Where on the map is the location of the type of vegetation identified?

Grid lines should be used along with compass direction.

(c) What is the extent of it?

Give relative terms, namely, extensive or small.

(d) What factors impact on the nature of the vegetation?

Natural vegetation may be found in areas that have steep slopes, rugged terrain and are relatively high. Cultivated crops, on the other hand, are usually found on gentle slopes, relatively flat land and where water is available, whether from streams or brought to the area by canals.

Some of you may have the complete map extract for the question being discussed. Use the following guidelines to answer the question:-

• In your description, separate sugar cane from forest.
  
  
• State where on the extract each is found.
  
  
• Note that sugar cane cultivation is found in most of the extract, even on steep slopes.
  
  
• Forested areas are concentrated in the north-west area, that is, Olivees Mountain and at elevation of over 1400 feet.

Let us now look at sub-section (h) of the question. It states:

Study the area along the south coast between Eastings 19 and 25. Describe TWO landforms.

The south coast is shown on the section of the extract that was published. Study it carefully to answer the question. I will continue with this section of the question in the next lesson.

Marjorie Henry is an independent contributor.