Given the record of this century, an extraterrestrial observer might conclude that conversion of raw materials to wastes-often toxic ones-is the real purpose of human economic activity

Lester Browne, Linda Starke, in : State of The World 1999, World Watch Institute report.[5]

"Whilst many cities today have a linear metabolism, nature's own ecosystems have an essentially circular metabolism. Every output by an individual organism is also an input that renews the whole living environment of which it is part" [ Herbert Girardet, in CITIES, PEOPLE, PLANET ]

With the above in mind, the URBAN Harvest approach has been developed.

A strategy to investigate all possible options for re-using the full output, and the potential sources within a urban/built environment system. It can be seen as a positive contribution to a cities needs, complementary to reducing negative impacts of consumption, or limiting inflow.

The total can be seen as the maximum potential resource harvest in a worst case scenario: If the urban organism ( "Orbanism") is cut of from its distant resource supplies, this is what it can supply itself maximum. If its more as it totally consumes, it could survive without adapting. If its to little, it has to find other resources or adapt its functioning. In this way, the Orbanism's "vitality" can be measured to overcome a crises, for each resource stream.

It should be studied how the urban 'organism' can (re-)organise itself to make maximum use of these possibilities .

It will require a high level or organisation, which in itself is available, but unexplored.

Harvesting the Urban Forest

Its necessary to change our traditional perception of a city, where people only live and consume resources, to a city where people (or activities) produce resources, partly as by-product of consuming. The potential is huge, if seriously explored and 'excavated'.

The strategy for this approach is: Urban Harvesting. The work so far carried out addresses the first explorations of the possibilities of this strategy, and the development of a first model to identify and manage the harvesting of all possible resources from within the urban environment.

The Urban Harvest strategy is defined to focus on:

1) make un-used resources and flows visible,

2) to develop a model and system approach

3) to inventorise the harvest potentials,

4) to investigate/develop if not available, technologies in the broad sense of the word to make them harvestable.

5) To study optimisation, adaptations of the urban environment to maximise harvests

6) To develop integrated approaches and organisational strategies to establish harvesting in many areas

Urban Harvest strategy

To collect any renewable primary resource, or any secondary resource , within an urban environment system, and to (re-) use these within that urban environment system.

In this approach we have identified 6 different streams: Resources are sorted in topics, by the way they come available from the "Urban machine" at its borders :

Urban Forest : all solids from day to day consumption

Urban Rivers : all liquids from day to day consumption

Urban Energy : all flows containing energy

Urban Farm : all eatable resources from within the system

Urban Quarry: all solids form the Built/constructed environment over time

Urban Space : all space free available in the urban environment over time *

*transport is adressed as " mobile space "

This is a practical approach close to the perception of involved stakeholders . For scientific research and or educational reasons, these can be further detailed into organic/non organic, liquid/gaseous or solids, hollows, for instance.