Environmental Engineering Reference
In-Depth Information
and Amanase-Whanabenya in Suhum-Kraboa-Coaltar district. Migrant cocoa
farmers founded them in the twentieth century (Gyasi
et al
., 1995).
Average annual rainfall ranges between 1,200 and 1,450 mm. It is bimodal and
adequate for two crops in a year. The major cropping season is from April to July
and the minor season from September to October, with the months of November
to March being associated with the dry
harmattan
season.
Soils are predominantly ochrosols. The vegetation has modified from a much
thicker true forest to secondary regrowth with a few pockets of thick forest
(Thompson, 1910; Chipp, 1927; St Clair Thompson, 1936; Taylor, 1952, 1960;
Hall and Swaine, 1976, 1981).
Despite growing monocultures there still is high agrodiversity. This reflects
both the transitional nature of the ecosystem, which permits cultivation of crops
adapted to humid and dry conditions, and the great ethnic and cultural diversity
arising from migration.
Located in Akuapem district, cradle of Ghana's cocoa industry, Gyamfiase-
Adenya is settled predominantly by native Akuapem people and Ewe migrant
farmers on the basis of a mosaic landholding pattern.
In Sekesua-Osonson, the inhabitants are mainly the offspring of Krobo migrant
cocoa farmers. They settled there on the basis of a patrilineal linear
huza
land-
holding arrangement.
Amanase-Whanabenya is settled by a mix of the offspring of migrant Akuapem
and Siade/Shai people and a growing component of recent migrant Ewe settled
farmers. Landholding arrangements are both the mosaic and linear
huza
type.
Suhum-Kraboa-Coaltar district forms part of the historic southern Akyem cocoa
frontier. As in Akuapem, the inheritance system is both matrilineal and patrilineal.
Farming by smallholders is the main occupation in all the sites. They grow
mainly food crops, notably cassava, maize, plantain, cocoyam, and oil palm.
Other economic activities include cassava processing, distilling of
akpeteshie
,a
local gin, and extraction of oil from the fruit and kernel of the oil palm.
Evidence of climate variability
There is an evidence of considerable climatic variability in the study areas. The
meteorological statistics are buttressed by claims of farmers with whom discus-
sions were held. Very nearly all of them reported substantial changes in the
climate, especially in volume and reliability of the rainfall, and intense sunshine.
Using four proxy rainfall stations, namely Akropong, Aburi, Koforidua, and
Suhum (Figs 4.1- 4.4) over a 30-year period, the trend displays fluctuations in the
annual rainfall totals. The coefficient of variability over the period was 18.9 per
cent for Koforidua, 20.3 per cent for Akropong, and 23.3 per cent for Aburi.
These figures point at a moderate to high rainfall variability.
