Study Session 6 Land Use and Urban Planning

Study Session 6Land Use and Urban Planning

WASH_1.0 OpenWASH

Study Session 6Land Use and Urban Planning

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· Introduction

· Learning Outcomes for Study Session 6

· 6.1Change of land use

· 6.1.1Decrease in natural and agricultural land

· 6.1.2Increased area of hard surfaces

· 6.1.3Extraction of building materials

· 6.2What is urban planning?

· 6.3Planning for sustainability

· 6.3.1Housing quality

· 6.3.2Infrastructure for water, sanitation and solid waste management

· 6.3.3Drainage systems

· 6.3.4Green spaces

· 6.4Urban planning in Ethiopia

· 6.4.1National Urban Development Policy

· 6.4.2Integrated Housing Development Programme

· Summary of Study Session 6

· Self-Assessment Questions (SAQs) for Study Session 6

Introduction

This is the second study session that looks at the growing trend for people to live in urban rather than rural areas. Study Session 5 described the main causes and effects of urbanisation. In this study session we will review how urbanisation changes the nature of the land surface and the consequences of that change. We will then consider the role of urban planning in reducing some of the negative effects of urbanisation and look at current urban development in Ethiopia.

Learning Outcomes for Study Session 6

When you have studied this session, you should be able to:

6.1 Define and use correctly all of the key words printed in bold. (SAQs 6.1, 6.2 and 6.3)

6.2 Explain the connections between land use and the physical environment. (SAQ 6.1)

6.3 Summarise the problems created by uncontrolled urban developments. (SAQ 6.2)

6.4 Describe how urban planning can contribute to sustainable urban living. (SAQ 6.4)

6.5 Summarise the achievements and challenges of the Integrated Housing Development Programme. (SAQ 6.5)

6.1Change of land use

We depend on land to provide many essential life-supporting systems.

· Think back through the previous study sessions and consider the different ways that we all use land. What different types of land use can you think of?

· We use the land to provide food from agricultural activities; to supply wood from trees for construction and fuel; for water which is extracted from rivers and lakes on the land’s surface or from underground, and to provide rocks and building materials.

You may also have thought of the land that is used when we build houses, shops, factories, roads and other components that make up the urban environment. This is the aspect of land use that we will be focusing on in this study session.

Land use can be defined as arrangements, activities and inputs by people to produce, change or maintain a certain land cover type (FAO/UNEP, 1999). This definition makes it clear that there is a link between land use and land cover. Land cover is the observed biophysical cover on the Earth's surface. In non-urban areas land cover is usually described by the dominant vegetation type, such as forest, grassland or cropland. Changing the way the land is used (for example by building towns and cities on it) changes the land cover and has many direct and indirect effects.

Most consequences of changing land use through urbanisation can be grouped into two main categories: the decrease in natural and agricultural land, and the increase in hard surfaces of built-up areas.

6.1.1Decrease in natural and agricultural land

Change from non-urban to urban land use causes the loss of many different types of vegetated land cover. This may be grassland used for grazing animals, cultivated fields that produce food and other crops, uncultivated areas of river banks and hillsides, and wooded areas covered with trees. Deforestation was discussed in Study Session 1 as one of the negative impacts of human use of resources.

· What are the main negative effects of deforestation?

· Deforestation can reduce the infiltration of water into the soil and groundwater, which can lower the water table and increase the volume and speed of surface run-off; if this happens it can increase soil erosion because the land surface is exposed. Deforestation also results in a loss of wildlife habitat and a reduction in biodiversity; and the loss of ecological services provided by trees (such as converting atmospheric carbon dioxide to oxygen by photosynthesis). You may also have mentioned the loss of the aesthetic value of trees, which are attractive elements in our biophysical environment.

The reduction in agricultural land also shifts the balance in the land area available for food production. The most productive land for agriculture tends to be near to towns. When towns expand this land gets covered with buildings and so it is no longer available for food production. This means there is less productive land available to meet the increasing demands for food from a growing urban population. The additional demands for food production in the areas around towns and cities can encourage the increased use of pesticides and fertilisers to improve productivity, which can have negative environmental impacts. It also encourages the cultivation of previously unused land such as sloping hillsides which, when ploughed, are extremely vulnerable to soil erosion when it rains.

6.1.2Increased area of hard surfaces

The construction of urban areas increases the area of hard surfaces such as roofs, roads, and pavements. Unlike the natural land cover they replace, these hard surfaces are impermeable, meaning water cannot pass through them. When rain falls it does not infiltrate into soil and groundwater but instead pours off the surface very quickly. Water collects in gutters and drains and flows directly into rivers and ditches, which rapidly fill up and can overflow. The volume and speed of the flow of run-off leads to frequent flooding in many city areas (Figure 6.1). These problems are made even worse if there is no drainage system or if drainage is inadequate or becomes blocked with rubbish.

Figure 6.1Flooding in an urban area.

In addition to the effect on the water cycle, the increase in hard surface area also influences the exchange of energy with the atmosphere, which can lead to localised changes to the weather and climate. In large cities the temperature can be a few degrees warmer than in surrounding rural areas, an effect known as an urban heat island. This is caused by the hard surfaces of roads and buildings, which absorb energy from the sun and radiate heat into the surrounding air to a much greater extent than natural vegetated surfaces, especially at night. The raised temperature can increase the impact of poor air quality on people’s health.

6.1.3Extraction of building materials

A third category of changed land use is the extraction of rocks and minerals for the construction industry (Figure 6.2). This process results in the loss of vegetated land cover where the rocks are extracted. Most of this resource extraction takes place in peri-urban areas because they are located conveniently close to the construction sites to minimise transport costs and time. Many small-scale, unregulated and low-technology extraction activities can be seen on sites around towns in Ethiopia.

Figure 6.2Construction of new buildings uses many different resources.

These impacts of change in land use from rural to urban, combined with the effects that you read about in Study Session 5, add up to a lengthy list of negative consequences from urbanisation. Managing and minimising these effects is one of the main purposes of urban planning.

6.2What is urban planning?

Urban planning is about designing towns and cities to function effectively and meet the needs of people living in them. This is a technical process, concerned with bringing benefits to people, controlling the use of land and enriching the natural environment. It requires careful assessment and planning so that community needs such as housing, environmental protection, health care and other infrastructure can be incorporated.

Urban planning means managing urban development so that uncontrolled and haphazard building is prevented. Unplanned development in peri-urban areas can lead to towns and cities spreading out and extending the impacts of change of land use over an ever-increasing area. In central urban areas, unplanned development gives rise to densely-packed, single-storey housing with narrow alleys making it very difficult to provide necessary services for the inhabitants (Figure 6.3). The negative effects of impoverished, informal settlements were described in Study Session 5.

· What are the main negative impacts of slum areas on the people who live there?

· The main problems are the poor quality of housing construction materials, overcrowding, and limited access to water and sanitation, which combine to create unhealthy living conditions.

Figure 6.3Close-packed houses in Addis Ababa.

Unplanned urban development is characterised by poor housing quality and by the lack of supporting infrastructure and services. These inadequate services can include any or all of: electricity, water supply, sanitation, drainage, solid waste management, roads and transport facilities, shops and schools and health care. The lack of available space in central urban areas also results in people building insecure homes in unsafe places, as shown in Figure 6.4. Urban planning aims to address these problems.

Figure 6.4Houses perched precariously close to the flooding Akaki River in central Addis Ababa.

Historically, the concept of urban planning arose in Europe in the 19th century (Corburn, 2005). It emerged from the awareness that public health and infectious disease outbreaks were closely related to inadequate housing and poor sanitation, particularly affecting the urban poor. By the 20th century, the idea of land-use zoning was the dominant approach to urban planning. Zoning meant the creation of defined areas within a town that were designated for different activities such as residential, commerce, industry, etc. The aim was to improve urban living conditions by separating people from ‘noxious land uses’ (Corburn, 2005). However, zoning also had the effect of creating a social divide by separating areas where well-off people lived from those occupied by people with little or no income, with increasing inequality between the services and facilities available in different zones. Excluding people from living in central zones that were allocated for commerce and business resulted in increasing urban sprawl, where the effects of urbanisation and land-use change were spread over larger areas (UN-Habitat, n.d. 1). Recommended urban planning practice has since moved away from the zoning approach and currently adopts principles of integrated use designed to ensure the sustainability of future towns and cities.

6.3Planning for sustainability

You could say that the purpose of urban planning is to manage land use so that it is sustainable. This means it should bring economic benefits, with social equity and without causing environmental harm. The promotion of ‘socially and environmentally sustainable human settlements development’ is part of the mission of UN-Habitat, the United Nations programme that is ‘working towards a better urban future’ (UN-Habitat, n.d. 2). They set out five principles for urban planning, shown in Box 6.1 (UN-Habitat, n.d. 1).

Box 6.1UN-Habitat’s five principles for sustainable neighbourhood planning

The UN-Habitat approach to urban planning is based on three key features of sustainable neighbourhoods and cities, which are that they should be compact, integrated and connected. Five principles support these three features:

Adequate space for streets and an efficient street network.
High density of people: at least 15,000 people per km2.
Mixed land use: housing mixed with business and other economic uses.
Social mix: houses in different price ranges and tenures (rented, owned etc.) in any given area.
Limited land-use specialisation: large areas should not be allocated for a single function.

In contrast with the zoning approach, these five principles emphasise the need for mixed land use developments that integrate different functions of residential, commercial and business together. Ideally, urban plans should mix housing with employment opportunities and include schools, shops and health care facilities. An adequate street network will allow access for cars, public transport and service vehicles. Plans should also consider the need for space for places of worship and for entertainment and leisure. Incorporating this diverse range of requirements for the urban environment is challenging. To be successful and sustainable, urban plans should ideally be developed with the participation of the people who will be living and working in the area. Meeting these expectations also requires significant economic resources, an effective decision-making and regulatory framework, and good governance.

We will now consider in a little more detail some aspects of sustainable urban planning that are particularly relevant to WASH, the environment and health, but are typically absent from unplanned developments. These are: housing quality; the infrastructure related to water, sanitation and solid wastes management; drainage systems; and green spaces.

6.3.1Housing quality

One of the key elements to address health problems in poor urban areas is the quality of housing construction. Houses must be built with materials that are waterproof and durable, using appropriate construction techniques and following correct procedures. Regulatory systems need to be in place to ensure that buildings are constructed to a specified standard and monitoring procedures should be established to ensure compliance. However, the affordability of housing also needs to be considered. A research study found that the majority of households in Addis Ababa were unable to afford to build dwellings that met the standards set in 1994 and 2003 (Bihon, n.d.).

6.3.2Infrastructure for water, sanitation and solid waste management

If you were planning a new water supply system for a town the first thing you would need to consider would be the source of water. (Some aspects of water source selection were discussed in Study Session 4.) Key questions include: Will there be enough water to meet the needs of the people living in the town? Will there be enough to meet future demand, say for the next 10 or 20 years? Is the quality of water acceptable? What water treatment will be needed to ensure the water is safe to drink? How far is the source from the town? And how will the water be moved from the source to users? Answering these questions is a complex technical process requiring models and calculations based on the number of people using the supply, expected use for non-domestic purposes, future expansion and growth, and geographical and hydrological survey data. In addition, for a piped water supply system, the infrastructure plan would include details of the network of water mains that deliver water to the users, with the layout of pipes and pumps required to distribute water to the new buildings.