PhD Thesis Emmanuel Obeng Bekoe - Cranfield University

Emmanuel Obeng Bekoe Phd Thesis Chapter 2 Hydrol, Humid Tropics & Study Area
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percent of the farm labour force is women. Agriculture contributes 54 percent of
Ghana’s GDP and accounts for over 40 percent of export earnings while at the
same time providing over 90 percent of the food needs of the country. Ghana’s
agriculture is predominantly smallholder, traditional and rain-fed (SRID, 2003).
The drainage network of Ghana is divided into three main systems (WARM,
1998):
• The Volta river system is the largest drainage system in Ghana. The
Black Volta, White Volta and the Oti rivers flow from Burkina Faso
southwards to Ghana to form the Lower Volta. This river system
catchment accounts for about three quarters of the total land area of
Ghana, and has been dammed at Akosombo and at Kpong for
hydropower power generation. Behind the Akosombo dam, one of the
largest manmade lakes in Africa has been created, with a surface area of
8 500 km 2 and a capacity of 148 km 3 .
• The southwestern river system drains about one-fifth of the total land
area of Ghana. The system comprises the Bia, Tano, Ankobra and Pra
rivers.
• A number of coastal rivers drain the southeastern part of the country.
Together, they account for 5% of the land area of the country and the
Densu Basin falls in this category.
The mean annual runoffs from the 3 major river basins within the country are
respectively: 24175x10 6 m 3 , 13125x10 6 m 3 and 2110x10 6 m 3 and they contribute
61.3, 33.3 and 5.4% respectively of the actual runoff from Ghana (WARM,
1998).
2.4.2 Densu Basin: Location, Socio-economic, Drainage and
Relief
The Densu River is a typical rain forest zone river and forms part of the coastal
river basins of Ghana, taking its source from the Atwiredu Range of hills of the
Eastern Region (a recognized administrative region) of Ghana. It lies between