Assessment of sugar beet lime measure efficiency for soil contamination in a Mediterranean Ecosystem. The case study of Guadiamar Green Corridor (SW Spain)

Abstract

Contamination has been identified as one of the main threats for soil conservation worldwide. Availability of high-quality information on soil contamination, its impacts and effects is still required at global level. Well documented case studies provide valuable information to understand long-term trends associated with management of contaminated soils. The temporal evolution of contamination and associated factors have been studied in the Guadiamar river basin, after a mine waste spillage of about 6 hm3 of acidic waters and toxic sludge enriched with trace elements. An extensive database has been compiled, harmonized and standardized from the numerous and heterogeneous sectorial studies and monitoring carried out in the area since 1998, and has been used for spatio-temporal analysis of the effectiveness of individual and mixed soil remediation measures as a pilot case for data exploitation. Database variables consider six ecosystem compartments (soil, water, sediment, air, plant and animal biomass), management (remediation measures applied over time and space), land use and cover, and present and predicted climate. The pilot developed for remediation effectiveness considered 11 different treatments, including mixed addition of compost, red clays and sugar beet lime (SBL). Harmonization and Standardization processes were carried out according to EU-HYDI, INSPIRE and ENVASSO recommendations. However, correlation and regression analyses were applied to standardize pH and Cd values from our case study with R Software. According to the land use, high doses of SBL with other soil amendments don't provide high benefits for the reduction of Cadmium pseudototal. The created database provided a relevant resource of information for the management of the Guadiamar area and other similar cases. Also, the present methodology and harmonized data-based will be useful for soil contamination assessment across Europe allowing the development of decision support tools and decision making for the selection of effective and available remediation strategies.