(a) Highlight characteristic features of the Tropical Continental Climate. (b) Describe the vegetation of the Savanna region.

Answer Details

(a) Characteristic features of the Tropical Continental (Sudan/Savanna) Climate

• It lies roughly between latitudes 5° and 15° north and south of the Equator.
• Distinct double season: a wet season in the high-sun period and a long dry season in the low-sun period.
• Total annual rainfall is moderate, about 50 cm to 100 cm, decreasing towards the poles/desert margins.
• Rainfall is convectional and falls mainly in one maximum during the wet season.
• Temperatures are high all year, generally 21°C to 32°C, with the hottest period just before the rains.
• The annual temperature range is greater than in the equatorial zone (about 8°C or more).
• Relative humidity is low, especially in the dry season when the dry, dusty Harmattan wind blows.
• Skies are largely clear in the dry season, giving high sunshine and strong evaporation.

(b) Vegetation of the Savanna region

• It consists mainly of tall grasses interspersed with scattered trees, giving a parkland appearance.
• Grasses grow tall (up to 3-4 m) in the wet season and dry up, turning brown, in the dry season.
• Trees are deciduous and drought-resistant, shedding leaves in the dry season to reduce water loss.
• Trees have adaptations to drought and fire: thick, fire-resistant bark, long tap roots, small leathery leaves and umbrella-shaped crowns (e.g. baobab, acacia, shea, locust bean).
• Vegetation is zoned by rainfall: it changes from Guinea savanna (moist, taller trees) through Sudan savanna (shorter grass, fewer trees) to Sahel savanna (thorn scrub) as rainfall decreases polewards.
• Grasses are tufted, growing in tussocks rather than continuous turf.