(a) Draw an outline map of Nigeria On the map, mark and name (i) latitudes 5°N, 13°N and longitude 8°E, (ii) one area with rainfall of about 600 mm, (iii) o...

(a) Outline map of Nigeria

Key locations marked on the map:

1. The parallels 5°N and 13°N, and the meridian 8°E.
2. The Maiduguri/Borno area in the north-east, receiving about 600 mm of rainfall annually.
3. The Calabar/Cross River coastal area in the south-east, receiving about 2,000 mm to 3,050 mm of rainfall annually.
4. Maiduguri in the low-rainfall area and Calabar in the high-rainfall area.

(b) Rainfall pattern in Nigeria

1. Rainfall is not uniformly distributed in Nigeria. Its amount generally decreases from the coast northwards into the interior.
2. The coastal belt and the south-east receive the heaviest rainfall, generally over 2,000 mm annually. Parts of the coastal and south-eastern area receive up to about 3,050 mm or more.
3. Rainfall is lowest in the extreme north, especially around the Lake Chad and north-eastern areas, where annual totals may be about 600 mm or less.
4. The duration of the rainy season decreases from south to north. Coastal areas have rain for about 8 to 10 months, whereas the far north has about 3 to 4 rainy months.
5. Southern Nigeria has a double-maximum rainfall regime, with peaks commonly around June and October.
6. A short dry spell, called the August break, occurs between the two southern rainfall maxima.
7. Northern Nigeria has a single rainfall maximum, usually around August or September.
8. There are two main seasons: a rainy season and a dry season. The dry season becomes longer and more severe towards the north.
9. Areas of high relief, such as the Jos Plateau and the eastern highlands, receive more rainfall than surrounding lowlands because uplift of moist air produces relief rainfall.
10. The onset and movement of the rains follow the seasonal migration of the Inter-Tropical Discontinuity (ITD). Rain may begin with thunderstorms and may occasionally be heavy enough to cause flooding.