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Urban environmental management and issues in Africa south of the Sahara

The process of urbanization in Sub-Saharan Africa
The nature of environmental problems
Causes of the current problems
The way forward
Concluding remarks


R. M. K. Silitshena


Africa is the least urbanized continent but one where the rate of urbanization is among the highest. The rapid rate of urban growth is causing social and economic strains, some of which manifest themselves in environmental problems. An environmental problem has been defined as "either an inadequate supply of a resource essential to human health or urban production (e.g. sufficient fresh water) or the presence of pathogens or toxic substances in the human environment which can damage human health or physical resources such as forests, fisheries or agricultural land" (Habitat 1989: 6).

A number of environmental problems that occur at varying spatial scales from the home through the neighbourhood, the city to the region are reviewed. The problems include the crowded and cramped living conditions and the presence of pathogens in the human environment because of lack of basic infrastructure; the dangerous and unhealthy sites of some neighbourhoods and the irregular or noncollection of garbage in some neighbourhoods; the city-wide problems of the disposal of toxic/hazardous wastes, and water, air, and noise pollution; and the problem of energy and vegetation, which encompasses a much wider region.

There are many causes or factors contributing to these problems. They include massive rural-urban migration, poor planning and ineffective development control, weak urban institutions, and inadequate financial resources.

A number of suggestions are made for the improvement of the situation. They include institutional reform, improvement of financial viability, and a review of standards.

The paper starts with the background to the process of urbanization in Africa. I then deal with the nature of environmental problems and give explanations for the present situation. Finally, I look at what can be done to improve the situation.

The process of urbanization in Sub-Saharan Africa

Africa is the least urbanized continent but one currently experiencing the fastest rate of urbanization (O'Connor 1983). Africa, however, has a long history of urbanization (Hence 1970), although the most formative period started with colonialism. There are therefore many traditions of urbanism in Africa, and O'Connor has identified six, namely: indigenous, Islamic, colonial, European, dual, and hybrid city (O'Connor 1983: 28-41). Even this is not a neat categorization because '`many individual cities will occupy only marginal positions between these categories" (ibid.). But it serves to underline the need to recognize the diversity of urban centres between and within African countries. The complexions of urban problems, as indeed policy prescriptions, will vary from one type of town to another.

The colonial influence has, however, been widespread and pervasive. In much of eastern and southern Africa most towns are creations of colonial exploitation and domination. The cities were created to facilitate the exploitation and export of natural resources to metropolitan countries of Europe. They started as commercial, administrative, and mining towns and as ports. The pre-existing indigenous towns, most widespread in western Africa, have been affected by colonial and post-colonial policies. All types of African city have experienced growth, although this has been much slower with indigenous cities (O'Connor 1983). Other common elements of African urbanization include the existence of a primate city (or cities) superimposed on a large number of small settlements; the rapid physical expansion of the towns, resulting in the loss of agricultural land or absorption of nearby villages; ever-increasing demand for water, fuel, services, transport, and housing, all of which are beyond the cities' budget to satisfy; and the thorny issue of waste disposal. These problems are partly manifestations of poor management.

The main engine of urban growth is rural-urban migration (Todaro 1976; Gugler 1982; O'Connor 1983; Van Western and Klute 1986). The urban population in the selected African countries has at least doubled since 1960, with changes in proportions and growth rates as shown in table 6.1. The main motivation for migration is economic - the search for better-paying jobs, especially by young men. The trend, however, is for women migrants as well as the older married men to increase. Some studies have found that women migrants were in fact in the majority (Gwebu 1982; Van Western and Klute 1986). Many women are wives, daughters, and fiancees arriving to join their male relatives in town, but they also come to seek employment.

The increase in the numbers of females partly explains one trend of rural-urban migration - the tendency for migration to be long term or even permanent and to reflect a shift from individual to family migration. Long-term migration has been explained by the increasing difficulty of finding jobs in the formal sector (Van Western and Klute 1986). This has implications for urban planning: increasingly, policy makers and planners are having to plan not for circulating but for permanent and stable urban populations.

There are other reasons for migrating to towns. They include personal security in countries where there is political strife and warfare and the desire for better services, which are located in urban areas. As a result of urban-biased development, the quantity and quality of health and education services are higher in urban than in rural areas (Sparks 1990). Although there is evidence of stepped migration in some countries, most migration is directed to the large cities. More than 42 per cent of all urban populations live in cities of more than 500,000, compared with only 8 per cent in 1960 (Sparks 1990). There were only two cities in the region with a population exceeding 500,000 in 1960; if present trends persist, there will be 60 cities with more than 1 million by the year 2000.

The phenomenon of rural-urban migration cannot be fully comprehended outside some of the problems in the structure of African economies. There has been a general economic decline since independence, so that some poor countries are poorer now than they were at independence. In the process of impoverishment, Africa has lost the ability to feed itself and both food imports and food aid have continued to rise (Sparks 1990). The major explanation for this malaise lies in the neglect of agriculture, Africa's most important activity:

Table 6.1 Urban growth of selected African countries, 1960-2000

  Urban population (as % of total) Urban population annual growth rate (%) Population in largest city (%)
Country 1960 1990 2000 1960-90 1990 2000 1980
Botswana 2 28 42 13.5 7.9 -
Gabon 18 46 54 6.3 4.9 -
Swaziland 4 33 45 10.5 6.7 -
Namibia 15 28 34 4.8 5.4 -
Lesotho 3 20 28 8.6 6.3 -
Zimbabwe 13 28 35 5.9 5.4 -
Zambia 17 50 59 7.1 5.5 35
Cameroon 14 41 51 6.5 5.7 21
Ghana 23 33 38 3.9 4.6 35
Cote d'lvoire 19 40 47 6.5 5.5 34
Zaire 22 40 46 4.8 5.0 28
Nigeria 9 29 37 5.8 6.2 17
Rwanda 2 8 11 7.4 7.6 -
Uganda 5 10 14 6.1 6.6 52
Senegal 32 38 45 3.5 4.4 65
Equatorial Guinea 25 29 33 1.5 4.0  
Malawi 4 12 16 6.5 6.5 19
Ethiopia 6 13 17 4.8 5.8 37
Sudan 10 22 27 5.4 4.8 31
Mozambique 4 27 41 9.5 7.2 83
Angola 10 28 36 5.9 5.4 64
Benin 9 38 45 7.4 5.0 63
Chad 7 30 39 7.1 5.4 39
Burkina Faso 5 9 12 4.6 6.3 41
Niger 6 20 27 7.4 6.7 31
Mali 11 19 23 4.4 5.2 24
Guinea 10 26 33 5.3 5.8 80
Gambia 13 23 30 5.2 5.3  
Sierra Leone 13 32 40 5.2 5.1 47

Source: UNDP (1991).

Many governments have pursued economic policies that were designed to keep urban wages (and living conditions) high and farm prices low; have maintained the value of currencies at unrealistic rates of exchange... This is understandable and obvious. Political power in Africa rests in the city, not in the village. (Sparks 1990: 35)

In Mali, for example, the government policy in the 1960s was to curb rural-urban migration by forcibly repatriating unemployed migrants as a means of reducing the build-up of political opposition (Van Western and Klute 1986). Subsequent policy relaxed migration regulations but alleviated the effects of low wages by keeping prices of food products low. This policy resulted in lower producer prices and further depressed conditions in the rural areas (ibid.).

A recent study in Kenya found that "often the husband brings home maize and other commodities bought in town where competition deflates prices" (Andreasen 1990: 165). The study found a strong dependency of rural families on urban wages. The men, who live and work in town separated from their families, experience very harsh conditions: "There is no doubt that the image of life in rural areas which urban residents maintain, often is an illusion referring to a situation as it was many years ago, and perhaps sustained under the influence of hardships of urban life" (ibid.: 166).

On top of these unfavourable terms of trade against agricultural products must be added the ecological stresses of the African environment. Hjort af Ornas (1990) argues that the people in the Horn of Africa live in such a marginal environment that they have little room to manoeuvre. Thus the 1984 drought disaster left "as many as two thirds of the population as temporary refugees in towns and cities" (Hjort af Ornas 1990: 152).

The loss of soil productivity is a result of a number of factors that were set in motion by the colonial regimes: the introduction of export cash crops, which increased demand for land and reduced selfsufficiency in food crops; the expansion of cultivated land into grazing land as a result of rapid population growth; and the creation of state boundaries, which have put a brake on transhumant migrations and thus contributed to overgrazing, etc. (Vis 1989). All these factors manifest themselves in the shortage of land.

In some areas, holdings are no longer economic even under more intensive forms of agriculture (White 1989: 15; Andreasen 1990). These areas are characterized by landlessness. The alternative for people in these situations is rural-urban migration.

The role of rural-urban migration in contributing to urban population growth has been stressed because of the key role it plays in many countries. However, it must be realized that natural growth is assuming greater importance in long-established cities and some countries with a relatively long history of urbanization. Indeed, the rural population of the region has continued to grow and these trends are expected to persist (United Nations 1991). The rate of urbanization is projected to decline by 1995-2000 (ibid.).

To conclude this section, Sub-Saharan Africa is the world's poorest region with an estimated two-thirds of the rural population living in absolute poverty (Sparks 1990). The gap between rural and urban incomes is at least fourfold (White 1989). A number of countries have had to accept various structural adjustment programmes since the mid-1980s. Continuing drought in much of the region and lack of protection from excessive competition in years of overproduction (e.g. 1985-1986) have further undermined the rural economy. In the meantime, the rational thing to do for any African on the land has been to migrate to urban areas.

The nature of environmental problems

We can discuss the environmental problems at different but interconnected scales that range from those that affect the home to those that operate at a regional level (Habitat 1989).

Environmental problems of the home

The majority of the urban population - e.g. 65 per cent in Dar-esSalaam (Mosha 1990), 67 per cent in Blantyre (Mwafongo 1991), and 80 per cent in Luanda (Hill 1992) - live in squatter settlements. Squatter settlements refer to shanty towns, most of which start as illegal settlements. These settlements are characterized, among other things, by poorly constructed houses, poor sanitary conditions, lack of all services (power, running water, and garbage collection), and lack of legal status as residential dwellings. Izeogu (1989) has described such a settlement in Port Harcourt as follows:

There is a total lack of public services and infrastructure such as piped water and residential access roads. There is no provision for sanitation and drainage facilities, separate kitchens or children's play areas. The population density is also very high... Most houses are below acceptable standard; their condition may also be deteriorating; the level of household facilities such as kitchen, flush toilets, and piped water to the house is very low; most residents depend upon a bucket toilet. (Izeogu 1989: 62)

Houses suffer from the prevalence of pathogens because of the lack of basic infrastructure and services such as sewers, drains, or services to collect solid and liquid wastes and safely dispose of them (Habitat 1989). These pathogens are a cause of many debilitating and endemic diseases that afflict poor households. The diseases include diarrhoea, dysentery, typhoid, food poisoning, and intestinal parasites.

One of the basic problems is lack of running water. The majority of residents living in squatter settlements have no access to potable (clean) water. In Nigeria, for example, only a limited number of houses have running water (Nwaka 1990). The majority of households depend upon various, and often unsafe, sources of water such as streams, wells, itinerant vendors, stagnant pools, and springs (Mosha 1990; Nwaka 1990; Mwafongo 1991). Such water is often contaminated by untreated effluents from industry and by sewage and is a source of many children's diseases. Where standpipes are provided, they are so few as to make a very limited impact.

With a few exceptions (e.g. Mutizwa-Mangiza 1990; MusanduNyamayaro 1991), sanitation is poor. Large parts of towns are not sewered. Most urban residents use pit toilets; others use a variety of unhealthy systems such as the bucket system. Nigerian towns are characterized by open drains, which are never cleaned and often clogged with all types of debris and garbage (Nwaka 1990). Even where sewers are provided, they are often blocked and overflow into the streets and attract harmful insects and bacteria (Mosha 1990).

The health problems are exacerbated by often crowded and cramped housing conditions. The numbers of persons per room are high (Izeogu 1989), which contributes to the spread of diseases such as tuberculosis, influenza, and meningitis. The spread of diseases is facilitated by limited resistance because people also suffer from malnutrition. Among children, diseases such as mumps and measles take a heavy toll. Accidents, particularly among children, are also common from fires, stoves, and kerosene heaters (Habitat 1989).

The unhealthy home environment is paralleled by an equally unhealthy environment in the workplace arising from dangerous concentrations of toxic chemicals and dust, inadequate lighting, ventilation, and space, and inadequate protection of workers from machinery and noise (Habitat 1989). These problems arise because of inadequate legislation and lack of enforcement.

Many factors have brought about the development of squatter settlements. The basic causes include the high demand for housing in the wake of rapid rural-urban migration, the slow growth of the housing stock, and the low incomes of the majority of migrants. It has been observed that, where the minimum standard of accommodation is costly, environmental quality may be sacrificed in favour of other goals: "Each low-income individual or household will choose the sacrifice to be made in terms of size of accommodation, the terms under which it is occupied, the suitability of the site, housing quality, the location and access to infrastructure and basic service" (Habitat 1989: 15). For many African urban residents the choice of where to live is almost predetermined; they cannot afford the cheapest lowcost housing. In most instances such housing is not even available, so that even those who might afford it are forced to join the squatters. The waiting lists for low-income housing are typically long. In Mozambique, for example, the construction of new houses ceased in 1976 (Gumende 1990), while in Malawi "new construction and servicing of new plots has drastically declined" (Mwafongo 1991: 21).

In Zimbabwe, the government has always been hostile to squatting and has not allowed the process to take root. Recently, however, with government inability to cope, there are signs of softening on the policy as squatting is grudgingly being accepted (Africa South 1992). Harare suffers from a scarcity of serviced land, insufficient funds, rapid population growth, and a shortage of building materials (Southern African Economist 1990).

Problems of the neighbourhood

The problems of the home merge into or are part of the wider problems afflicting the neighbourhood. Two problems, the siting of settlements and the poor collection of household garbage, will be discussed.

Squatters often select land that is likely not to be demanded for any other use in order to minimize the possibility of eviction. Such sites are likely to be dangerous or unhealthy. They include hillsides, flood plains, and polluted land sites (e.g. near solid waste dumps or industrial areas or areas with high levels of noise pollution such as in proximity to airports). Such land may have the additional advantage of being cheap or close to jobs (Habitat 1989). Squatter settlements in the Cameroon towns of Douala and Yaounde occupy quarry sites and marshy sites in valley bottoms.

The second major problem is waste disposal. A variety of wastes is generated. Izeogu (1989) found six factors that affect solid waste generation in Nigeria, including population growth, urbanization, social development, income class composition, and diffusion of technical competence. He found that, with improvements in incomes of the urban employed, consumption patterns changed so that the emphasis shifted to packaged products, which tend to produce large amounts of litter such as plastics, tins, and bottles.

Most cities do not have sufficient capacity to deal with the garbage that is generated. Dar es Salaam, for example, generates an estimated 2,000 tonnes of refuse a day but the city's removal capacity is only 100 tonnes a day (Mosha 1990). In Nigeria, Nwaka has estimated that only 30 per cent of waste is satisfactorily disposed of; the rest is dumped by the roadside or into nearby rivers and streams (Nwaka 1990). In many cases, refuse collection is restricted to high-income areas (Leduka 1991; Mwafongo 1991). There are no regular collections, if any, in the squatter areas, and the uncollected refuse soon attracts rodents, flies, and other vermin.

Where refuse is collected, it is often dumped at the edge of the city. The waste is untreated and is often a mixture of both domestic and industrial waste (Segosebe and Van der Post 1990). This causes pollution of the soil and the ground water. Meanwhile the built area gradually extends towards the dumps and in time surrounds the waste dump (White 1989; Musandu-Nyamayaro 1991).

The situation with respect to waste disposal is very serious because its direct effect on the quality of the environment is tremendous. Izeogu has observed: "By 1983 the large volumes of solid waste generated in Port Harcourt had changed the aesthetics of the urban environment. Garbage completely blocked some streets in Diobu and various parts of the city were dirty, unhealthy and visually unpleasant" (Izeogu 1989: 64).

It is unfortunate that, in cities such as Harare that have been coping, "residents are now resorting to emptying uncontrolled refuse in open spaces" (Musandu-Nyamayaro 1991: 8).

Problems of the city environment

Just as the home merges into the neighbourhood, so the neighbourhood merges into the city region. The main environmental problems at the city level are related to various aspects of pollution. Although pollution problems such as air pollution may be considered unimportant because of the low scale of industrialization, they may be as serious as in developed countries in certain localized areas. These are the major centres, particularly capital cities, where industries are concentrated.

The first problem concerns the disposal of toxic or hazardous wastes. The main sources of hazardous wastes include heavy metals, oxides of nitrogen and sulphur, and petroleum hydrocarbons (Habitat 1989; Christiansson 1993). Most of these come from the chemical industries, although other industries such as primary and fabricated metal and petroleum industries and leather tanning industries also produce significant quantities of hazardous substances (Habitat 1989; Izeogu 1989; Christiansson 1993). Effluents are discharged into the rivers, lakes, or estuaries, some of which are sources of drinking water (Izeogu 1989; Christianson 1993). Alternatively they may be dumped with ordinary domestic garbage and thus cause soil and groundwater contamination (Segosebe and Van der Post 1990). There are no effective regulations and institutions regarding the handling and disposal of such materials (Segosebe and Van der Post 1990; Habitat 1989).

It has been observed that: "The major cause of industrial pollution is the lack of consideration given to pollution and human health aspects when formulating and assessing industrial projects. Most of these projects are planned and assessed according to technical, economic and, in some cases, political criteria" (Christiansson 1993: 3).

As already indicated, water pollution from industrial effluents is a serious problem. Other sources of water pollution are sewage, garbage, and human excrete. In Port Harcourt, the piped water supply in some parts of the city was found to contain unacceptable levels of coliform (Izeogu 1989). As already noted above, most residents of squatter settlements depend upon contaminated sources for their water supply.

Air pollution is becoming a serious problem in some big centres. The sources of air pollution are industry, fuels for heating and electricity generation, the burning of garbage, some mining operations such as quarrying, and motor vehicles (Habitat 1989; Izeogu 1989; Mosha 1990). Motor cars, which are often poorly maintained and congested in narrow streets, contribute substantially to air pollution through emissions of carbon monoxide, oxides of nitrogen, and hydrocarbons. In addition, there is lead pollution as a result of less stringent regulations on the lead content of petrol.

Noise pollution is one of the problems in large cities. The sources of noise pollution include highway traffic, industrial operations, and aircraft (Habitat 1989). In some cases, desirable maximum levels of outside noise (65 decibels) are exceeded. In Port Harcourt, measurements in excess of 80 decibels were recorded (Izeogu 1989). The major cause of the problem is the lack of regulations and institutions to check noise pollution (Habitat 1989).

We can conclude this section by noting that, although various types of pollution are generally not yet a major problem, they constitute serious hazards in some large cities.

Environmental problems affecting the region beyond the city

The effects of some of the problems discussed above go beyond the city boundaries. A good example is water pollution. The effluents dumped in streams pollute the water used by rural communities (Izeogu 1989).

The other way in which the city affects its neighbouring communities is through the exhaustion of natural resources. Thus, as cities grow, the demand for water increases and sources further afield must be tapped. In these cases cities may compete with local communities for water and contribute to the fall in the levels of aquifers (Claassen 1990).

The other area of natural resource stress is energy. The main source of energy in urban areas is charcoal, followed by fuelwood (White 1989). The advantage of charcoal is that it is lighter and therefore easier to transport, but it is 40 per cent less efficient than fuelwood (ibid.). Consequently, urban dwellers cause greater deforestation per capita than do rural dwellers. In Malawi, it is feared that the shift from commercial fuels to wood may increase deforestation (Mwafongo 1991).

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