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close this bookInitial Environmental Assessment: Urban Development - Series no 12 (NORAD, 1996)
close this folderPart I: Urban development. The urban environment, projects and environmental impacts.
close this folder1 The urban environment and relevant project categories
View the document1.1 Introduction
View the document1.2 Project categories
View the document1.3 The urban environment

1.1 Introduction

The distinction between rural and urban areas is usually relatively unproblematic and generally related to degree of development. However, among professionals this distinction has been focused for some time, with efforts being made to develop various criteria to distinguish between urban and rural areas. Clearly defined rules and criteria are important in order to observe urban development and its impacts. In industrial countries the most important criteria for classification of areas have been population density, distance between houses, the structure of the economy and population figures. The need for clearly defined criteria became apparent when one started to develop statistical overviews of urban population density and other demographic characteristics. Initially it was only necessary with a consistent definition for each individual country. As the international focus on problems related to urban areas has increased, comparable global statistics have become necessary. However, much of the current statistical data are difficult to compare.

The delimitation of urban areas is defined differently from country to country and can be complex. The differences are usually due to the variations of settlement types, economic structure, tradition etc. in the respective countries. In some countries the delimitation is based on administrative borders. This may generate problems as the cities may in reality expand or contain large unsettled areas within these borders. There are also large variations with regard to the definition of minimum population density for a settlement to be considered urban. Variations of this criteria are related to how densely populated the country is and how many large cities it contains. In most cases the limits are set between 1500 to 5000 inhabitants. The term village is used for communities characterised by a built-up area and a certain degree of communal rights to the utilisation of natural resources.

The global settlement patterns are to an ever increasing degree characterised by urbanisation, defined as those processes which cause an increasing concentration of the population in densely populated areas. This is connected to the increasing specialisation of the economic activity in the secondary and tertiary economies. Urbanisation entails certain fundamental changes that are geographical, physical, structural, economical, demographical, cultural and behavioural. In most industrial countries and some developing countries urbanisation has stabilised. However, most developing countries are in the middle of, or at the start of, an urbanisation process. Many developing countries also experience a considerable population growth, resulting in a rapid expansion of many cities in both Asia, Latin America and Africa the last twenty years.

The level of urbanisation is a measure for the number of urban dwellers compared to the total population in a country or area. In 1990, according to the UN, app. 37% of the population of developing countries lived in urban areas. The urban population is growing faster than the rural population. In 1980, 114 cities in developing countries had populations exceeding 1 million. In the year 2000 probably 400 cities will fall into this category. The world's largest city is Mexico City with 20 million inhabitants in 1990. Cities with more than 10 million inhabitants are often termed megalopolises. In 1950 there were no such cities in developing countries. In 1990 the number was 9, and projections indicate 14 by the year 2000. Less than 3% of the population in developing countries resided in megalopolises in 1990. Megalopolises can only develop in countries with substantial populations and considerable secondary and tertiary economies. The current urbanisation is dominated by the growth in small and mid-size cities. Hundreds of cities containing between 250.000 and 1 million inhabitants were small towns 40 years ago, and thousands of urban centres with less than 250.000 inhabitants did not exist or were only small villages. The largest portion of the urban population of the developing countries reside in urban areas with less than 500.000 inhabitants. If the country has a relatively small population the normal city size may be less than 100.000. (See Table 1 and Table 2 at the end of this booklet.)


Table 1: Urban population size in developing countries. Development tendencies 1950 - 2000:


Table 2: Population distribution between rural areas and urban areas of different sizes (1990)

Planning, administration and management, essential to cope with urbanisation, are often little developed or function poorly in many countries. Weak economy and national debt burdens contribute to this. Most cities in developing countries experience common problems like lack of employment opportunities. too little and often inferior housing, inadequate infrastructure and public services, serious environmental problems, poor health, large social inequalities and poverty. In the future there will probably be more urban poor people than rural poor. Urban environmental problems are due to complex cause-effect chains. In order to identify the correct measures it may be necessary to look closer at the connection between cause and effect. However, a fragmented perspective is often the case and leads to projects and programmes focusing individual extremely visible problems while ignoring other problems and the connections between them.

1.2 Project categories

In other booklets in this series this booklet (no. 12) has been referred to in cases where unplanned urban development may impact projects or development processes. In addition to identifying possible environmental impacts of this. the booklet will emphasise the description of environmental impacts of planned urban development. This pertains to areas without substantial prior settlement and for projects in existing urban areas.

The World Commission on Environment and Development emphasise in their 1987 report the necessity of sustainable development of urban areas. This was underlined at the UNCED conference on environment and development in 1992. Recently, several multilateral and bilateral programmes have been initiated. The objectives are amongst other to:

· Secure basic needs e.g. housing, food, energy, health, education, employment, transport etc. for a rapidly expanding population.

· Limit pollution and other environmental problems.

· Strengthen management, institutions, legislation and people's participation.

When defining the scope of this booklet it has been necessary to establish a delimitation in relation to the other booklets in this series. Several projects relevant to urban areas e.g. water supply, drainage, transport, industry, energy, mining and waste management are discussed in booklets 7, 8, 9, 10 and 11. Therefore these issues are only briefly discussed in this booklet. An exception is made for transport/ infrastructure which is discussed somewhat more thoroughly. This booklet will focus the environmental impacts of building projects and physical planning, as well as touching on issues of localisation and several strategies for urban development taking the environment into consideration. The following constitutes an overview of project categories which may be assessed with regard to environmental impacts with the assistance of this booklet:

· Building/construction projects, e.g.:

- Construction of houses, offices, warehouses, workshops, schools, hospitals etc. in connection with development projects, or as part of planned urban development.

- Housing development specifically for low-income groups and/or slum upgrading.

- Urban renewal or rehabilitation of individual buildings.

- Rehabilitation of areas affected by catastrophes.

- Establishment of refugee camps.

· Conservation projects (cultural heritage, landscape, architecture and recreational areas) e.g.:

- Conservation and rehabilitation of individual buildings or specific building environments and townships.

- Management of parks, cultural landscapes, and areas for recreation and tourism within or close to urban areas.

· Infrastructure projects like for instance:

- Construction of and/or rehabilitation of roads, public transportation etc. (See also booklet 8).

- Energy supply. (See also booklet 9.)

- Waste management, drainage, sewage systems and sanitary conditions, and other projects to limit discharges to water, air, and soil. (See also booklets 7, 8, 9, 10, 11.)

· Projects within physical planning.

- Physical planning includes for instance land use plans, and plans for production or conservation of facilities, buildings and other surrounding features.

Other relevant project categories in urban development are social infrastructure projects e.g. strengthening of education, health, sports, culture and social sector, and projects targeting public administration like institutional development, training, promotion of increased popular participation, legislation and research. Measures within these categories can be very important contributions to solving urban environmental problems. And with this as the objective they may serve as steps to more comprehensive strategies for environmental improvement or environmentally sound urban development.

1.3 The urban environment

Even though cities in developing countries do have some aspects in common (see section 1.1) it is not easy to sketch an image of the typical city or town in developing countries. Cities or towns are shaped by various historic processes, and every city has its own structure and character. Characteristics of many cities and towns, especially in Asia, are narrow streets, densely populated city centres, and economic activity mixed with housing similar to the European cities prior to industrialisation. The same description pertains to some cities in Latin America and West and North Africa. In Southern and Eastern Africa urban areas may be characterised by more open settlement and relatively broad streets in city centres.

Religious and cultural aspects may be important for the physical and social organisation of the cities, and be decisive for development patterns. In some communities this is strengthened through caste and social ranking systems. Central areas where administrative and religious functions are located may be identified as high status districts, while peripheral urban areas may be dominated by low status social groups. In some cities plans and decisions are defined by kings, religious institutions or the military. These and the upper class may be owners of large areas of land. In all cities the distribution of land impacts settlement patterns. Some land owners may for instance develop their land, while others speculate in future value increase causing large areas to lie abandoned. The population density of most cities in developing countries, including many of the largest, is not especially high if one considers the entire city. The settlement patterns are often characterised by relatively large areas with low population density between small areas with high density. Urban areas are constantly changing and developing. Many cities are experiencing suburbanisation where upper classes move from the city centre to the urban fringe because the city centre is becoming over-populated and polluted. Simultaneously some parts of the city deteriorate due to poor maintenance, and new business areas containing office buildings, hotels etc. are developed. Another characteristic is that large and small land areas in the urban fringe or undeveloped land in the city centre are occupied illegally by the poor. Cities in developing countries generally have less industry than cities in the industrial countries. However, there are some cities or urban regions in developing countries containing extensive industry. In such cases the industry may have expanded rapidly without adequate planning and regulation.

Attempts at a general description of the urban environmental problems in developing countries may easily obscure important problems. Even in the individual countries the diversity between cities is immense, ranging from the capital and large cities to dozens or hundreds of small towns. Each city or town experiences its own range of environmental problems which may be affected by the population's size and density, type and extent of industrial production, climate. soil types, water resources and drainage, types of fauna and flora in and around the urban areas, etc.. It may also be difficult to give a correct picture of the environment in a given city due to poor or inadequate documentation. In addition there is a tendency that international awareness of important environmental problems in cities in developing countries is based on documentation from a few large cities. Since a considerable number of people live in small cities the lack of documentation of environmental problems is remarkable. Small cities usually have a less effective physical planning and pollution control than large cities. Some have considerable industrial production, but even without they may have substantial environmental problems related to poor water supply and drainage, water pollution, inadequate waste management, uncontrolled growth and land use etc..

A description of some important conditions and processes that should be focused in the planning and implementation of development projects is given below.

1.3.1 Uncontrolled urban growth

Reports have indicated that roughly 1/3 of urban growth in developing countries is due to migration from rural areas to urban areas. The growth of the population already resident in urban areas is often underestimated. Population statistics may be inadequate and conceal significant factors, for instance that a large part of the population has not been registered as inhabitants or do not reside permanently in the city. Many may move back and forth between urban and rural areas to participate in seasonal work, others may migrate between cities.

The migration from rural to urban areas can both be explained in terms of factors that pull people to urban areas and factors that push people away from rural areas.

People may be forced to move from rural areas because of population growth, lack of land and/or work, poor access to health services and education, ecological collapse, natural catastrophes, war and hunger. Urban areas may seem attractive by being able to provide employment, school and health services. For some the urban culture may be especially attractive. Men usually move first with women and old people remaining in the rural areas. However this scenario is becoming increasingly nuanced. Urbanisation may be staggered through the population moving from village to the nearest town, and from there to the city. In many African countries the rural - urban migration is to smaller cities rather than large cities. In large cities the possibilities of employment are often less than in smaller cities. New inhabitants of smaller cities may also have more opportunity to supplement their income through cultivating food crops.

The growth of urban areas is in many places rapid and uncontrolled, without public administration or planning. The situation may expose certain common factors from place to place, for instance that public services and infrastructure e.g. roads, water supply, sewage and electricity supply are established after the allocation of plots for house construction. The design of the urban areas may become fragmented and resource demanding due to lack of comprehensive planning, and environmental problems may result. Physical development factors may be similar, but the causes can vary from place to place. Comparisons of uncontrolled urban growth in different cities, like for instance the growth of squatter areas (c.f. 1.3.3), organised land invasions and illegal plot allocation, may easily contain fallacies if the underlying processes are not known. Uncontrolled urban growth may be due to lack of resources or lack of political will to plan. The respective planning traditions of the country in question may be of importance for what is considered a public responsibility and what planning entails. The absence of public planning does not necessarily mean that growth is completely out of control. It may be regulated by local norms, demands and private land tenure.

1.3.2 Poverty

Recent research has shown that the extent of urban poverty in developing countries is larger than first assumed. In some of the poorest countries more than half of the urban population is below the official poverty line. Many so-called poverty lines are defined on the basis of income, but overlook health indicators as well as social indicators and other aspects of poverty. For many the conditions can therefore be very poor even if they are not considered below the prevailing poverty line. Generalisations regarding urban poverty are often incorrect as the extent varies greatly between cities and within cities. However, some general aspects can be highlighted; for instance that women and children usually experience the most serious effects. In several chapters in this booklet the importance of urban poverty is stressed, and how it affects the conditions in both small and large cities in developing countries.

1.3.3 Housing, place of work and health

Social inequalities characterise the housing conditions within cities in developing countries. Poor population groups usually reside in areas with low standard houses and high population density, while more affluent groups may reside in better houses in areas with considerably lower population density. Among the poor, housing areas are small, down to 2-3 m² per person in some cities in India. In addition recreational areas may be small, and in many cities the standard of housing is sinking.

Residential development can be sub-divided into three categories: Authorised or conventional housing, which is developed within the framework of a legal administrative system. Slum areas, which may be defined as older housing which was initially developed within the framework of a conventional system, but which is now subject to degradation. Squatter settlements, where housing is developed outside the conventional system and where housing does not fulfil legally defined quality requirements.

Squatters are poor immigrants or refugees who establish their houses (permanent or temporary) on public or private property with or without permission, or through rent or leasing. The areas utilised are often not suited for residential development and may be situated along transport routes, or in the vicinity of landfills and land vulnerable to landslides, floods, pollution etc.. In some cities large parts of the population (up to 50%) live in slum or squatter areas where much of the housing is constructed with poor building materials. In large cities many poor live on the streets and have set up temporary shelters on pavements etc.. Slum and squatter housing is seldom connected to adequate sewage/waste water treatment and water supply systems, sanitary conditions, waste management systems or other infrastructure. Poor people without water supply must buy water from water vendors and may have to pay several times more per litre than people who reside in affluent neighborhoods with a public water supply. Private water vendors supply between 20-30% of the population in developing countries with water. In houses containing water supply and drainage systems the facilities may be in poor shape due to intensive use (for instance many sharing toilets) and poor maintenance. Lack of waste management may lead to large quantities of organic and other solid wastes not being collected, which may result in smell and attract contagious organisms or pests, or block drainage canals, etc.. In addition human excrete may constitute a considerable pollution problem. Many types of disease-carrying organisms live, eat and multiply in and around houses and settlements in such urban areas. Gastro-intestinal diseases and diarrhoeas, but also diseases spread by insects, spiders or mites e.g. malaria, dengue fever and hepatitis, are common. Diseases normally defined as rural have become a problem in many urban areas. This includes malaria which is the most common cause of child mortality in poor quarters of cities. People may also live so crowded that the risk of domestic accidents, acute respiratory diseases and airborne spread of contagion is immense.

Problems related to housing typology, population density and health in poor urban areas are not primarily due to lack of land. Most cities and towns in developing coun tries have relatively large areas with non-utilised valuable land (cf. 1.3) which are not prone to landslides, floods etc.. The problem is that the poorer population groups do not have access to such land. The housing policies may in many countries be characterised by lack of resources and lack of willingness to implement a policy which focuses the poor. Governmental emphasis on housing development may be small, and private initiatives are often more common. Housing development will play a prominent role on the political arena, and will be central in the years to come.

Poor indoor environment may affect health (cf. 3.6). Use of open fire or poor stoves for cooking or heating may in many places cause pollution of indoor air. Smoke from wood, coal or other biomass may contribute to respiratory diseases. Many poor inhabitants use their home as a workshop or for production of goods. The goods may be intended for sale on the street, a small shop, or a bar or cafe related to the house. The indoor environment may be affected by problems with regard to light and ventilation, use of toxic or combustible chemicals etc.. Problems with the indoor environment and accidents at the place of work are also a considerable problem in small and large factories in the cities. High concentrations of toxic chemicals and dust, poor ventilation, light and localisation, and poor protection of workers from machines and noise are common. Health injuries related to the place of work may affect the individual seriously because social support systems like health benefits and compensations for injuries and illnesses are lacking.

In cities in developing countries large sections of the work force may work in production and service industries which are not registered or run in accordance with public regulations. This sector is often termed the informal sector. Large sections of the work force may, completely or partly, be employed in this sector. In India this may pertain to as many as 40-60%, of the urban work force. Individuals, families or company owners employ themselves and others in activities based on personal resources without any formal security. The scope of activities is broad and includes everything from shoe polishing to small scale industries, workshops and waste management. The informal sector has by some been regarded as unwanted. Many still maintain this, though a growing number currently view the informal sector as dynamic and worthy of support, especially with regard to meeting the needs of women. Unofficial entrepreneurs will probably always exist among the millions of poor in large cities, regardless of government or development policies. Due to lack of other employment many poor initiate production which may be both beneficial and harmful to society. The challenge in the future will be to show how the informal sector can create employment in a manner beneficial for the city and the society. Currently there are examples that informal sector activities are among the worst polluters, for example tanneries, and that they contribute considerably to the massive and increasing pollution problems of large cities.

1.3.4 Landscape, architecture and cultural heritage

Landscape can be considered both as nature, form and culture. In cities the man-made physical environment dominates the natural environment and creates an urban landscape. When the built-up area interprets or responds to the existing landscape, one may say that the identity of the place is strengthened. This is expressed amongst other through building traditions (cf. 2.1). The historic development changes the place(s), but certain characteristics are lasting and create what may be called the ambience of the location (genius loci).

The architecture in urban areas in developing countries may be categorised in several ways: a) Local building traditions and locally developed architecture, b) imported architecture from the colonial era, c) modern international architecture, and d) mixed types where traditional forms are mixed with modern. Many cities are characterised visually by the contradiction in terms between these expressions. Cities in for instance Asian or Arabian countries had well developed city cultures and local urban architecture before the colonial era and modernism entered the scene. The building traditions of earlier periods still characterises these cities. Some Central-African countries had for instance a less developed urban culture and therefore do not have a distinct and unique urban architecture. Even though many cities in developing countries have a long and rich cultural history, they are being increasingly influenced by international architecture. Old narrow city structures are in many places being replaced by high-rise buildings and broad streets. Changes must be viewed in light of the changes elsewhere in society and desires for architectural changes to reflect growth. The design and localisation of the building are of great importance to the urban image. Important aspects are the location of the building on the plot, the length of the building, the height, the shape of the roof, use of materials, colour, and composition of facades and details. The buildings may also contain architectural signs and symbols of social or cultural importance, for example religious buildings. The urban architecture may be regarded as a sum of physical fragments which express cultural values and attitudes, and which may be understood as the result of historic events and production processes where many different trends have joined together or have been in conflict with each other.

The cultural heritage is defined as all indications of human activity in the physical environment, including sites related to historic events, religion or tradition. Cultural environments are defined as areas where the cultural heritage is considered part of a larger holistic setting. Both buildings, settlement patterns, transport facilities and various individual objects of different nature and size can be part of the cultural heritage. When the conservation value of the cultural heritage and environment is to be considered this may be done on the basis of characteristics like knowledge values; for instance events, history of buildings, social communities, cultures or industries. Or one may consider experience values; for instance identity or aesthetic values. Or value of use; for instance economic value, user potential and pedagogical potential. And finally criteria like representability, uniqueness, age, homogeneity or variation, period expression, and authenticity may be considered. Authenticity is defined as genuineness related to given times or time periods.

1.3.5 Natural environmental conditions

The natural environment conditions in developing countries are characterised by large variations in topography, rainfall and temperature. The variation in environmental conditions between arid and humid areas is especially significant. Many urban areas are exposed to natural hazards, e.g. earthquakes, storms and floods. Some tropical environments in the vicinity of urban areas like rain forests, savannahs, coral reefs, mangrove areas etc. contain an extensive biological diversity and represent conservation-worthy environments and natural resources where the impacts of human activity is often considerable. The number of vulnerable and conservation-worthy fauna and flora species is often great in these areas, and the composition of species and the function of the ecosystem may be little known. In practice it may be very difficult to predict the impacts an urban development may have on an ecosystem. This also pertains to environments with less diversity of species, for instance arid or semi-arid areas, or for instance wetlands which contain a rich biodiversity and which may represent important habitats for birds etc.. The coastal environments in tropical areas may be spawning grounds for valuable and large stocks of fish and shellfish.

There is reason to be especially concerned if the projects or urban development impact especially vulnerable areas e.g.:

· soil vulnerable to erosion,
· areas vulnerable to land degradation or desertification,
· tropical rain forests or other valuable forests,
· wetlands,
· coastal areas with small islands, seaweed, coral reefs and mangrove swamps,
· conservation-worthy fauna or flora species and their respective biotopes, and
· vulnerable or especially important groundwater areas and water courses.