ghana climate change vulnerability and adaptation assessment

5. PHYSIOGRAPHY,ECOLOGICAL ZONES, ANDLIVELIHOODSPHYSIOGRAPHIC ZONESLike most of the West African mainland, Ghana is largely flat or gently undulating and >50 percent of thecountry is 450-600m. The southwest part of the basin is bordered by the northwest to southwest trending Kwahu Plateau (animportant climatic and drainage divide in Ghana), which forms a natural part of the Ashanti Uplands. Thewestern part of the basin is bordered by the Akwapim-Togo ranges, which begin just north of Accra andstretch northeastward into Togo. The highest peak in Ghana, Mount Afadjato (885 m elevation) is situated inthe Akwapim-Togo Range along the eastern border. The lowest lying areas in Ghana occur in the middleVolta Basin and in a broad belt along the coast (Dickson and Benneh, 1988; Owusu-Ansah, 1994; MSE, 2002;Borrow and Demey, 2010). From a geographic perspective, the country can be sub-divided into severaldistinct regions: Low Plains, Ashanti Uplands, the Volta Basin, and the High Plains (Owusu-Ansah, 1994).LOW PLAINSThe Low Plains roughly parallel the coastline and can be divided into four subregions: the Coastal Savanna,the Accra-Ho-Keta Plains (including the Volta Delta), and the Akan Lowlands. A narrow strip of grassy andscrubby coast runs from a point near Takoradi in the west to the Volta River in the east. This coastal savanna,only about 8-km wide at its western end, stretches eastward of Accra through the Accra Plains, where itwidens to >80 km and terminates at the southeastern corner of the country at the lower end of the Akwapim-Togo Ranges (Owusu-Ansah, 1994).The Accra-Ho-Keta Plains begin near the southern terminus of the Akwapim-Togo Ranges near Accra andstretch north and eastward forming a large triangle in southeast of the country near the border with Togo.The Plains are almost flat and featureless and descend gradually from an inland height of about 150 m to theGulf of Guinea. East of Accra the Plains are marked by a succession of ridges and spoon-shaped valleys andjust west of Accra, the low plains contain wider valleys and rounded low hills with occasional rockyheadlands. In general, however, the land is flat and covered with grass and scrub and classified as savanna.The Volta Delta (or Keta Plains), which extends into the Gulf of Guinea in the extreme southeast of Ghana,forms a rather distinct subregion of the Low Plains. The rock formation of the Delta, consisting of thicklayers of sandstone, some limestone, and silt deposits, is flat, featureless, and relatively young. As the Deltafanned outward over time, sandbars developed across the mouths of the Volta and smaller rivers that emptyinto the Gulf in the same area, forming numerous, often large, lagoons (Owusu-Ansah, 1994).The largest part of the Low Plains is the Akan Lowlands, which lie to the west and north of the CoastalSavanna and Accra Plains. Some classify this region as a subdivision of the Ashanti Uplands because of themany characteristics they share. Unlike the uplands, however, the height of the Akan Lowlands is generallysea level to 150 m. Some ranges and hills rise to about 300 m, but few are >600 m. The lowlands that lie to52 GHANA CLIMATE CHANGE VULNERABILITY AND ADAPTATION ASSESSMENT