Introduction
Urbanization is a global megatrend. While the rate and nature of urbanization differ
greatly between regions of the world and across SSA, the proportion of people living in
urban areas has been rapidly increasing at a global level, in many cases at unprecedented
rates, and particularly in many developing and emerging regions and countries. In 2014,
around 3.9 billion people lived in settlements classified as urban; equivalent to 54 per
cent of the world’s population.5 at a global level, this figure is expected to reach 66 per
cent by 2050. By way of comparison, in 1950 just 30 per cent of the world’s population
was urban. While increased proportions of people living in larger towns and cities can be
observed throughout much of the developing world, rates of urbanization in Africa,
particularly SSA, are, in general, lower than in other regions. In Africa, 40 per cent of the
population lives in urban areas compared with 48 per cent in Asia, which is the next least
urbanized region of the world. The process of urbanization is expected to continue in the decades ahead, however, with the figures rising to 56 per cent and 64 per cent,
respectively, by 2050, and with SSA frequently described as the latest and most rapidly
urbanizing region. The urbanization process is bringing major changes in economic and
social development processes, with significant implications for inclusive development,
investment, markets, infrastructure and finance in both rural and urban areas. There is a
high degree of heterogeneity across different regions and countries in Africa. In Eastern
Africa, urbanization rates are still very low, with just one quarter of the region’
population living in urban centres in 2014. By contrast, Middle Africa, Northern Africa
Southern Africa and Western Africa6 all have higher proportions of the population living
in urban areas: 44 per cent and above. The highest urbanization rates in Africa are found
in Southern Africa7 and Northern Africa. While agglomeration in urban centres can offer
certain development advantages – for example by enhancing access to services,
generating economies of scale in the provision of education, health services,
infrastructure, energy, water and sanitation, and business services – many people who live
in rural areas, and particularly those in more remote areas, are often unable to access
these services at reasonable cost in terms of time and resources. These people include
social categories that typically constitute the majority of the poor and hungry:
smallholders, particularly rural women and young people, the poorest people in rural
areas, migrants and indigenous peoples (IFAD 2016). According to Redman and Jones,
2004, basically urban growth is a combination of three basic processes. First is ruralurban
migration: it is a key source of urban growth since the origin of cities. Rural-Urban
migration is driven from perceived economic opportunities, insecurity in rural areas,
climate or economic problems, etc. Second is natural increase: this is a combination of
increased fertility and decreased mortality rate. Third is re-classification of land from
rural to urban categories: Many cities are rapidly growing into their fringe, engulfing
former villages and farm lands and transforming them into urban development. The rate
of natural increase is generally slightly lower in urban than in rural areas. However, the
principal reasons for raising the level of urbanization and city growth are rural-urban
migration, geographical expansion of urban areas through annexation and transformation
and re-classification of rural village into small urban settlements (Cohen, 2006).
The urban population living in poverty has rapidly increased during the past two decades,
along with rapid urbanization. The United Nations Centre for Human Settlements
(Habitat) reported that in 1990, at least 600 million people in urban areas in Latin America, Asia and Africa were living in life — and health-threatening conditions. The
additional 600 million people who would be added to urban populations in developing
countries during the 1990s would increase the pressure on land, housing, water and
sanitation, food supply and distribution systems, and education and health services, and
would add to the urban population living in poverty.
Urban agriculture provides a critical livelihood and source of food for many urban
dwellers, particularly low- income households in developing countries. Urban
agriculture, for the most part, is an informal activity practised by poor and landless city
dwellers. It usually refers to small areas, such as vacant plots, gardens, verges, balconies
and containers within the city used for growing crops and raising small livestock or milk
cows, for family consumption or for sale in neighbourhood markets.3 Peri-urban
agriculture refers to farming near cities, generally intensive semi- or fully commercial
production. Based on a combination of national census data, household surveys and urban
research projects in a number of cities, it is estimated that at least one quarter and in some
cases a much bigger percentage of urban and peri-urban households in developing
countries are involved in agriculture (see COAG/99/10).
Urban Agriculture (UA) and peri-urban agriculture can be defined as the growing,
processing, and distribution of food and other products through plant cultivation and
seldom raising livestock in and around cities for feeding local populations.1 2 Over the
last few years,
UA has increased in popularity due to concerns about climate change and sustaining food
security in urban areas. The effects of climate change has induced crop reductions and
affected optimal environmental growing conditions through rising temperatures and
changes in rainfall patterns.
However, while urbanization brings a number of socio-economic benefits, the rapid
increase in urban population ushers in a number of challenges. Urban authorities find
themselves heavily challenged in terms of their capacities to provide adequate services
such as housing, infrastructure, facilities and employment. The continued expansion of
urban areas into the immediate hinterlands often leads to the conversion of potential
agricultural lands into non-agricultural land uses. This takes place at a time when many
cities are saddled with the challenge to tackle growing unemployment and poverty. Some
cities have adopted urban agriculture as a strategy to address the increasing urban unemployment, poverty and hunger. This is because urban agriculture supports food
security and nutrition, provides employment and generates income for the urban poor in
general and the disadvantaged groups such as women, the disabled, the elderly and the
unemployed youth (van Veenhuizen, 2006). According to Armar-Klemesu (2006), about
200 million urban dwellers in the world participate in urban farming and the sector
provides about 800 million people with at least some of their food.
Although, agriculture contributes to 30% of anthropocentric greenhouse gas (GHG)
emissions, presence of vegetation in urban areas can lower temperatures and GHG
emissions. An environmental Life Cycle Assessment (LCA) of Urban Food Growing in
London found urban farms could potentially reduce food related GHGs, such as CO2 by
34 tons per hectare.
Increasing urban food deserts in many parts of the world has motivated the improvement
of methods of UA in order to complement urban food needs.
Other than the socio economic benefits of urban agriculture for both rural and urban
dwellers in terms of creating job opportunities, increasing food supply, and raising the
income of poor urban households, urban agriculture plays a paramount role in
environmental conservation. Due to the favorable climatic conditions, areas used for
urban agriculture are green throughout the year. This contributed towards the creation of a
micro-climate, as well as to the aesthetic value. Ever greenness also helped to clean the
air by reducing dust and protecting the soil from erosion. Indeed, urban agriculture can
protect areas from being used as sites for the unhygienic dumping of wastes.
Therefore, it is fundamental to have a deep investigation on the social, economic and
environmental effect of urban agriculture. Thus, this proposal tries to explore the value of
this environmental benefit of urban agriculture together with other economic benefits.
Recreational opportunities and amenities are important human-use services generated by
urban green spaces. the affinity of humans to greenery tends to transcend geographical
and cultural divides. The desire to recreate in green areas and live near them has universal
appeal. A livable and sustainable city is often characterized by ample provision of highcaliber
urban green spaces at strategic locations for enjoyment of residents, workers and
visitors. Recreational opportunities and amenities have been identified as important
human-use services generated by urban green spaces (Robinette, 1972; Grey and Deneke,
1986; Smardon, 1988; Botkin and Beveridge, 1997; Baines, 2000; Lorenzo et al., 2000).
Residents usually highly value green spaces and some are willing to pay directly or
indirectly for their benefits and amenities (Bolund and Hunhammar, 1999; Tyrv¨ainen and Miettinen, 2000; Tyrv¨ainen, 2001). The valuation of nature’s contribution to
humanity has extended from extra-urban areas to cities, including the important functions
furnished by urban green spaces. High quality green spaces can bring joy and a healthy
life style to people, and their design and location constitute a key component of urban
planning (Tyrv¨ainen and V¨a¨an¨anen, 1998; Tyrv¨ainen, 2001) in the quest for healthy
communities and sustainable cities.
Many intangible and indirect benefits of urban green spaces, as a non-market commodity,
could be usefully translated into monetary terms. Citizens and policy makers can
understand their contributions and justify resources for their provision and upkeep.
Methods to price non-market benefits could assess recreational and aesthetic values of
green spaces (Garrod andWillis, 1999; Price, 2003).