Zanzibar and Pemba
The islands of Zanzibar and Pemba are located in the Indian Ocean. Zanzibar is 22 miles (35 km) off the coast of mainland Tanzania; Pemba, 35 miles (56 km). Low-lying Pemba, whose highest point reaches an elevation of 311 feet (95 metres), and Zanzibar, which reaches 390 feet (119 metres), are islands whose structure consists of coralline rocks. The west and northwest of Zanzibar consist of several ridges rising above 200 feet (60 metres), but nearly two-thirds of the south and east are low-lying. Pemba appears hilly because the level central ridge has been gullied and eroded by streams draining into numerous creeks. On Zanzibar Island short streams drain mostly to the north and west. The few streams in the east disappear into the porous coralline rock.
Among the 10 types of soils recognized in Zanzibar are fertile sandy loams and deep red earths, which occur on high ground; on valley bottoms, less-fertile gray and yellow sandy soils are found. The eight soil types in Pemba include brown loams; pockets of infertile sands are found on the plains.
Zanzibar and Pemba have precipitation levels of about 60 inches (1,520 mm) and 80 inches (2,030 mm), respectively. Precipitation levels are highest in April and May and lowest in November and December. Humidity is high. The average temperature is in the low 80s F (high 20s C) in Zanzibar and the high 70s F (mid-20s C) in Pemba; the annual temperature ranges are small.
Plant and animal life
Long-term human occupation has resulted in the clearance of most of the forests, which have been replaced with coconuts, cloves, bananas, citrus, and other crops. On the eastern side of the islands, especially on Zanzibar, there is bush (scrub).
Although there is some difference between the animal lives of the two islands, it is generally similar to that on the mainland. Animal life common to both islands includes monkeys, civet cats, and mongooses. More than 100 species of birds have been recorded in Zanzibar.