The life cycle impact assessment applied to the Domingo Rubio tidal system by the study of seasonal variations of the aquatic eutrophication potential

摘要

The innovative technique of Life Cycle Impact Assessment (LCIA) applied to dynamic environmental systems has been recently developed. In this work we investigate a complex system, the Domingo Rubio tideland (Huelva, Spain), where a tidal marsh and a continental lagoon converge. This wetland, catalogued as Natural Park by the Andalusia government, is subjected to a high eutrophicant pressures related to the strawberry culture and the inputs coming from industrial wastes. NO_2~-, NO_3~- and PO_4~(3-) were analyzed in 41 water samples, obtaining values up to 100 mg L-1 ∑(NO_2~-, NO_3~-) and 18.5 mg L-1 PO_4~(3-). All these values exceed the accepted levels by the European Environment Agency. N/P ratios and the Aquatic Eutrophication Potentials (AEP) for N and P showed a constant imbalance of the system. During one tidal cycle, the tidal channel can have both N and P as limiting nutrient (P is the limiting nutrient during low tide and N is during high tide) and there exists an alternation of AEP domination too between N and P in the continental area, what points to an excess of both nutrients all over the study area, and to the necessity of diminishing the nutrient inputs and a higher control on these pollution sources as well.