Physical and Natural Environment

The Ablekuma West Municipality is located in the Western part of Accra (Figure 1). It lies within Latitudes 5°47'30"N and 5°27'30"N and Longitudes 0°31'30"W and 0°16'30"W. The Municipality shares boundaries with Ablekuma North Municipal Assembly to the North, Accra Metropolitan Assembly to the East, and Weija –Gbawe Assembly to the West. Also to the Gulf of Guinea to the South. It occupies a land area of approximately 15.01 sq. km with about 25 settlements with population above 200,000.

Geology

The geology of the Assembly consists of Coastal Sand and Mixed (Quartzite and sandstone). The coastline has a series of resistant rock outcrops, platforms and sandy beaches near the mouth of the lagoons.  The coastline is exposed because of the close proximity of the continental shelf, a strong coastal and wind action subjecting it to severe erosion.  The soils can be divided into four main groups: drift materials resulting from deposits by windblown erosion; alluvial and marine motted clays of comparatively recent origin derived from underlying shales; residual clays and gravels derived from weathered quartzites, gneiss and schist rocks, and lateritic sandy clay soils derived from weathered Accraian sandstone bedrock formations.

In many low lying poorly drained areas, pockets of alluvial ‘black cotton’ soils are found.  These soils have a heavy organic content, expand, and contract readily causing major problems with foundations and footings.  In some areas, lateritic soils are strongly acidic and when saturated are prone to attack concrete foundations causing honeycombing.  Near the foothills are the large areas of alluvial laterite gravels and sands.  Many of these deposits are being collected for constructional purposes.

Climate

The Ablekuma Municipal Assembly lies in the Savannah zone.  The annual average rainfall is about 730mm within the two rainy seasons.  The first begins in May and ends in mid-July whiles the second season begins in mid-August and ends in October.  Rain usually falls in intensive short storms and gives rise to local flooding where drainage channels are obstructed.

There is very little variation in temperature throughout the year.  The mean monthly temperature ranges from 24.7°C in August (the coolest) to 28°C in March (the hottest) with annual average of 26.8°C.  As the area is close to the equator, the daylight hours are practically uniform throughout the year.  Relative humidity is generally high varying from 65% in the mid-afternoon to 95% at night.

The predominant wind direction in Accra is from the WSW to NNE.  Wind speed normally ranges between 8 to 16 km/hr.  High wind gusts occur with thunderstorm activity, which passes in squall along the coast. The maximum wind speed recorded in Accra is 107.4 km/hr. (58 knots).  Strong winds associated with thunderstorm activity often cause damage to property and mostly removing roofing materials.

Vegetation

There is evidence to suggest that the vegetation of the Assembly has been altered in the more recent past century by climatic and other human factors. Much of the Assembly was believed to have been covered by dense forest of which only a few remnant trees survive. A climatic change combined with the gradient of the plains and cultivation has imposed vegetation structures similar to those of the southern shale, Sudan and Guinea Savannahs all of which lie north of the Accra plains.

There are three broad vegetation zones in the Assembly, which comprise shrub land, grassland and coastal lands which consists of dense clusters of small trees and shrubs, which grow to an average height of five meters (5m). The grasses are mixture of species found in the undergrowth of forests. They are short, and rarely grow beyond One meter (1m). Ground herbs are found on the edge of the shrub. They include species, which normally flourish after fire.

The coastal zone comprises of two vegetation types, wetland and dunes. The coastal wetland zone is highly productive and an important habitat for marine and terrestrial-mainly bird life.  Mangroves, comprising of two dominant species, are found in the tidal zone of all estuaries sand lagoons. Salt tolerant grass species cover substantial low-lying areas surrounding the lagoons. These grasslands have an important primary production role in providing nutrients for prawns and juvenile fish in the lagoon systems. In recent times, wetlands are however being encroached upon. Protection of the coastal wetland zone is very important to the long-term sustainability of the fishing industry.

The bank lands have been formed by a combination of wave action and wind.  They are most unstable but stretch back several hundred meters in several places. There are several shrub and grassland species, which grow and play an important role in stabilizing dunes.  Coconuts and palms grow well in this zone, providing protection and also as an economic crop.  Most of the coconuts were planted in the 1920s but it is estimated that over 80% of those plantations have disappeared as a result of felling, disease and coastal erosion.  The loss of these trees is one of the principal reasons for the severity of erosion in some parts of the Municipality.

Aquatic Fauna

The open lagoon systems support a wide range of crustacean, mollusks, gastropods, predatory and bottom feeding fish. The lagoons are important breeding grounds giving adequate protection against large predator species and a continual supply of nutrients and organisms for food. The habitats of the lagoons are or have been modified by development and increasing levels of pollution. 

The ocean supports a wide range of pelagic and bottom feeding fish.  Common species are grouper, mackerel, cassava fish, African look down, sole shark and tiger fish.  Stocks of off shore species have not been depleted mainly because fishing techniques result in a significant loss of smaller fish from nets.  Evidence suggests that on-shore species are nearing exhaustion caused by excessive catches of juvenile and small fish.  The loss of this resource will have a substantial impact on the indigenous population of the area whose livelihood is dependent on fishing.