Flows and Effects

If you look at the EcoSpold 1 reference list of elementary flows you will find flows with terms like Transformation, from arable, non-irrigated in the same slot where other flows have terms like zinc and Aluminium, 24% in bauxite, 11% in crude ore, in ground.

ISO 14044 defines an elementary flow to be either:

(1) material or energy entering the system being studied, which has been drawn from the environment without previous human transformation
(2) material or energy leaving the system being studied, which is discarded into the environment without subsequent human transformation

Land transformations don't really fit that definition. This suggests that the data structures defined originally to hold information about elementary flows are being used to hold other kinds of information. This is not an unusual practice in IT systems, but it is not a very good practice and is usually adopted only when the IT system does not meet and cannot be effectively changed to meet, changing requirements.

The Earthster Core Ontology (ECO) introduces the concept of an Effect. Processes have effects on the environment. There are also also social and other effects. Emitting CO2 to the atmosphere is an effect of a process and this kind of effect is an elementary flow. So Elementary Flows are a subclass of Effect. Other kinds of effect such as land use and land transformation are modelled as effects in ECO, but they are not modelled as elementary flows; in those cases nothing is flowing and they do not fit the ISO 14044 definition of an elementary flow.

Elementary flows in ECO must have a flowable, i.e. something that flows. In accordance with the ISO 14044 definition, there are two subclasses of flowable, Energy and Substance.

Here we see the flexibility that use of Semantic Web allows, enabling the refinement of concepts and the introduction of new concepts as requirements change.