Ruralisation integrating settlements and agriculture to provide sustainability

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Ruralisation integrating settlements and
agriculture to provide sustainability

• Folke Günther

Dept. of Systems Ecology, Stockholm University
E-mail folke_at_holon.se URL http//etnhum.etn.lu.s
e/fg/index.htm
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Is energy cheap?
Availabilty for gasoline energy at gas station
(working time for one kWh)
Energy availability today About ten times more
than 1920
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Adaptation to cheap energy Case 1 agriculture
Improved wheat
High yield (seed production with residual energy)
The farmer takes care of
Wild wheat
Low yield (seed production with residual energy)
Pest defence
Competition with neighbours
Necessary functions
Seed distribution
Pest defence
Seed distribution
Planting
Competition with neighbours
by the use of fossil fuels
Planting
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Adaptation to cheap energy, Case 2 settlements
Assume Four persons living in a house
Saving potential about 32 000 kWh/yr(associated
with vulnerability to high energy prices)
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Will energy prices continue to be low?
This is what this workshop is about, so I will
not delay on that You all have a good insight
into theese matters.
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Will energy prices continue to be low?
The Big rollover
Will this be our gloomy future?
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However, the effects of decreased energy
availability must be considered

• For food production, nutrient availability is
  essential
• Of the nutrients, those with limited supply are
  essential
• Biological systems solved these problems about
  400 millon years ago
• Cyclic flows

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Why phosphorus?
The constituents of an animal (or vegetable) body
H O C N S P Na K Ca 64
H O C N S
With gaseous phases can be transported by the
air
P Na K Ca 64
Without gaseous phases must be transported as
solids or liquids
Na K Ca 64
More common in the Earth crust than in the body
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The HEAP trap

• Hampered

Effluent
Accumulation
Process
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Linear flows typical for western agriculture
Import of nutrients compensates export of
produce
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Linear flows
Fossil fuel demand Resource depletion
Fossil fuel demand
Fossil fuel demand
Fossil fuel demand
HEAP
Fossil fuel demand
Fossil fuel demand
Fossil fuel demand
HEAP
Fossil fuel demand
Fossil fuel demand
Resource depletion
A linear flow from sources to sea
Resource depletion
Energy demanding and unsustainable
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AGRICULTURE
The balanced agriculture settlement
SETTLEMENT
Hence, one person is in nutrient balance with
about 0.2 hectares of balanced agriculture
3-4 kg represents the phosphorus turnover of
about 5 persons
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Conclusion 1
About 6 persons are in nutrient balance with 1
hectare of balanced agriculture
This means that about 0.2 hectares of such
agriculture can support one individual without
HEAP effects
Given that the the agriculture provides the
people with food and nutrient containing residues
are returned to the agriculture
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Rules for sustainability

• You can not be dependent on storages

• Neither of energy

Solution Energy flows

• Nor of nutrients

Solution Recycling
Corollary Food should be produced as close as
possible to the consumer in order to diminish
food system energy needs and maximise nutrient
recycling capacity

• You must have a supportive function on your
  support system

Solution Improve (not just maintain) the health
of your ecosystem
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The eco-unit Area 50 ha for 200 inhabitants
Diversified agriculture
Functional size, pop. about 200
Providing most of the human foodand all of the
animal fodder
Open ditches
Orchards
Private gardens
Nutrient reclaimLandscape diversityPredator
habitatLee planting Biomass production
Biological greywater treatment plant
(wetpark)Clean water is returned to the
households
Fossil fuel demand is minimized vulnerability
to fuel price changes is minimized
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The ruralisation scenario start point
In this scenario, the following things are
supposed
A scenario is an imagination made by a scientist
4. Instead of building new houses on the places
where the old ones were torn down, they decide to
build eco-units in the periphery of the town.
1. The city is inhabited by decisionmakers who
have the capacity to make far-sighted and
strategic decisions
2. They have the same knowledge of limiting
resources, ecology and the principles of oil
depletion as you.
3. Furthermore, they understand that the city is
not static, but dynamic. Old houses are torne
down and new are built. (The average life-time
for a house is supposed to be 60 years, which
gives the city a rate of change of 1,6)
At start point, the centre of the municipality
has a population of 33 000The periphery is
inhabited by 3 000
The rules are You can imagine the most
ridiculous things But you have to render a
statement of the effects
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Ruralisation after 12 years
With the given rate of change, the centre of the
municipality has a population of 24 000The
periphery is inhabited by 12 000
Groups of four Eco-unitsEach group is inhabited
by 800 people
Local parks replacing the old houses
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Ruralisation after 25 years
At this stage, the centre of the municipality has
a population of 12 000The periphery is inhabited
by 24 000
Reversed ditching
Underground streams are brought up to the surface
5 600 persons
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Ruralisation after 50 years
At the end of the ruralisation process, the
centre of the municipality has a population of 3
000The periphery is inhabited by 36 000

• Minimal dependency of fuel storages due to
• Localised food-system
• Use of wind, solar-power and biomass

No HEAP-trapNutrients are circulated
Many characteristics of the area (P/R-ratio,
nutrient retention capacity, mutualism,
biodiversity) are closing to those of mature
ecosystems.
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The economy of ruralisation
In this calculation, it is not possible to
account for changes of the Rollover type.
Therefore, continuous, steady changes of energy
prices are assumed (In this case 5 annual
increase in price for industrial energy, and 2
for renewable energy sources)
Unchanged city
Ruralisation
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Conclusions
There is an immediate need for finding strategies
to avoid dependence on storages of
Energy
Nutrients
For sustainability, these strategies must also
include a supportive behaviour towards the
supporting ecosystems
Regarding these restrictions, the urban structure
common today is unsustainable
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Conclusions
To avoid dependence on storages of
Energy
use flows or funds
Nutrients
recycle
This will impose restrictions on distance
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Conclusions
These strategies can be established in the border
of the urban structures common today
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Conclusion
By advanced undulation of the borders, leading
to the integration of the city with its
hinterland, some obstacles to sustainability may
be overcome
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Wrong
Right
Society planning strategy
OK (?)
OK
Industrial energy availability Hard(gt 500
s/kWh)
OK (?)
Industrial energy availability Easy(lt 100
s/kWh)