Theoretical bases of the use of the irreversibilities concept in an ecosystem as an environment impact index are presented in this paper. Because an ecosystem is composed by different biotics and abiotics parts, each part has a specific function in the processes to transport energy inside the ecosystem, all these processes having a large dependence between them. When anthropogenic emissions is produced part of the useful energy of the process are used to assimilate or to absorb those emissions, and irreversibilities are produced in the processes of the ecosystem when emissions are made by the human beings. Thus, the work that an ecosystem can carry out varies as a function of the irreversibilities produced by anthropogenic sources; the permanency or loss of the ecosystem depends on how many irreversibilities it can support. The second law of thermodynamics through a systematic use of the exergy concept o lost work concept are the basis of this methodology. The ecosystem can be divided in subsystems, each subsystem interrelated with the other ones, and then an ideal work variation can be obtained from each variation in the ecosystem (being the subsystems the water, the soil, the atmosphere, the organisms and the society). Thus, a global index could be determined by adding the partial irreversibility of each subsystem, and could be used to determine the trend that an ecosystem will follow due to alterations of its pristine, original or environmental line base state. Applying the methodology presented here an index of environmental impact could be developed, not in a subjective or ambiguous way, but based on energy calculations. An index of environmental impact and its methodology, based on quantitative terms that enable to evaluate in a very clear way the harmful effects of industrial operations, such as the phenomenon of contamination of the environment, could be used as a tool in the analysis of sustainability, resource depletion or health effects.

This content is only available via PDF.
You do not currently have access to this content.