Inputs and Outputs of Urban Ecosystems
The inputs and outputs in urban ecosystem are based on consumption, production and
degradation of resources. For instance, the inputs into urban ecosystems include money,
energy, food, raw materials for industries, construction materials, land, air, water, animals
and plants for aesthetic reasons, among others. The inputs play a significant role in having
the urban ecosystems developed, established and managed. Most of the goods and services
(mentioned in the previous section), depend on the inputs into the urban areas from within
or the surrounding rural ecosystems
The outputs from urban systems are exemplified by the following: – Wastes (liquid, solid
and gaseous), which are produced during the utilization of the inputs, employment to
provide services and produce goods, education to enhance/promote information, science,
art, and technology, wealth generated from inputs, goods and services rendered, economic
and socio-cultural developments realized from the inputs, poverty reduction due to
improved quality environments and development in generally most cases. However, in
some urban environment such as slum areas, poverty levels can rise due to environmental
degradation and low levels of development. Whereas some outputs give advantage of
better urban ecosystems, others such as wastes pose a challenge and threaten quality
urban environment and sustainable development
Other challenges of urban environment and development
A survey carried by the United Nations Environment Programme in 1995 in various
cities globally showed other critical issues experienced in urban areas as follows:
Environmental Risks – such as flooding, industrial and residential conflicts e.g.
in Cotonou (Benin).
Environmental health problems – Malaria, gastrointestinal diseases and
upper respiratory tract infections are prevalent in Dakar’s poorer
neighborhoods’ and are linked to poor sanitation and waste management
(Dakar in Senegal).
Problems linked with rapid growth and poor land-use – Local authorities
have not been able to maintain existing infrastructure, let alone provide new
facilities to rapidly growing parts of the city (Nairobi – Kenya, Cotonou –
Benin). Liquid and solid wastes are poorly disposed of.
Water scarcity and agricultural development problems – accelerated
agricultural development is putting serious pressure on water resources (e.g.
Naivasha, Kenya and Ismailia, Egypt) and access to land is constrained by
urbanization, poor soil fertility and high salinity, chemically loaded waste
discharged by agriculture is affecting waste bodies flowing into the city’s lake.
Inadequate solid management, which includes inadequate coverage and
delays in collection, are causing a health hazard. Disposal by open site dumping
and burning is having negative public health and air pollution consequences.
Unequal access to environmental goods and services – Peripheral and
informal areas have no safe water supply and little access to sanitation,
drainage, waste management or electric power. Consequently, health and
economic problems arise from use of contaminated water, flooding, fire
outbreaks, wastes dumping and air pollution from combustion of low-quality
fuels kerosene, coal, and wood burned indoor (Durban, South Africa, Nairobi
and small towns, Kenya).
Degradation of ecosystems – Some cities are located in areas occupied by
sensitive and valuable ecosystems such as lakes, rivers and national parks, all of
which are deteriorating soil erosion, alien inevasive species dominate in many
areas, rivers are being polluted and forests are being stripped for firewood and
building materials (Durban, South Africa, and Nairobi, Kenya).
Loss of heritage – About 1800 buildings are considered to be of heritage value
in Delhi, India. Only 160 buildings are currently protected and over 400 have
Inefficient transportation – Poor people face an average transportation
problem. Due to the absence of adequate public transportation. This results in
high levels of vehicular emissions per capita and increased exposure to traffic
accidents (Durban in South Africa, small towns, Kenya).
Noise pollution – noise problems have been difficult to overcome. It will take
many years to reach acceptable levels e.g. Nairobi, (Kenya), Gothenburg,
(Sweden). Traffic congestion and air pollution from vehicular sources e.g.
Hyderabad (India), Nairobi (Kenya) and Madras/Chennai (India).
Proliferation of low paying informal sector retail trade such as Jua Kali in
Kenyan urban areas and Madras/Chennai, India.
Inadequate infrastructure in poor areas – Poor settlements (e.g. slums and
shanties) are characterized by a lack of water and sanitation services,
inadequate garbage collection, poor drainage, and roads, all of which create
health, economic and socio-cultural problems for residents e.g. Nairobi (Kenya),
Manila (Philippines), Wuhan (China), Kuching City (Malaysia) and
Johannesburg (South Africa).