Impacts of climate and land use changes on the water quality of a small Mediterranean catchment with intensive viticulture. (May 2017)

• Record Type: Journal Article
• Authors: Serpa, D.; Nunes, J.P.; Keizer, J.J.; Abrantes, N.
• Is Part Of: Environmental pollution. Volume 224(2017)
• Page Start: 454
• Page End: 465
• Publication Date: 2017-05
• Subjects: Nitrogen -- Phosphorus -- Copper -- Agricultural pollution -- Surface waters; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2017.02.026
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Studies that address the potential effects of climate and land use changes on surface water quality are scarce in the Mediterranean region. In the present work, the impacts of climate and land use changes on nutrient and copper exports from a humid Mediterranean catchment (São Lourenço) were evaluated using the SWAT model. SWAT reproduced reasonably well total nitrogen (TN), phosphorus (TP) and copper (Cu) exports in São Lourenço, providing an adequate baseline scenario as well as a suitable model parameterization for assessing the impacts of climate and land use changes under the A1B and B1 emission scenarios for the end of the 21st century (2071–2100). Land use changes scenarios were generated along the same storylines as climate change scenarios to assess the combined effects of the two stressors. Climate changes itself led to a decline in annual TN and TP exports under both emission scenarios mostly due to a decrease in runoff and erosion induced by a reduction in rainfall, but it hardly affected Cu exports largely due to its strong immobilization in soils. Land use changes per se resulted in an increase in streamflow, but the changes in water quality varied markedly according to the scenarios. A substantial decrease in TN, TP and Cu exports was observed under scenario A1B, due to a reduction in vineyard areas. Under scenario B1, however, TP exports decreased much less while TN exports hardly changed, reflecting differences in the preferential transport pathways of these compounds. Cu exports also remained the same, as no changes occurred in the vineyard areas. The combination of climate and land use change scenarios revealed additive impacts on the exports of all three contaminants, emphasizing the importance of integrated approaches to define adaptive land management practices that can ensure the future sustainability of Mediterranean water resources. Graphical abstract: Highlights: We evaluated the impacts of climate and land use changes on water quality. Climate change led to a decrease in total nitrogen, phosphorus and copper exports. Contaminant exports were strongly dependent on the type/extent of land use change. Combined climate and land use scenarios had additive effects on contaminant export. An integrated approach is needed to assess the future state of water resources. Abstract : The combination of climate and land use change scenarios revealed additive impacts on the exports of agrochemicals (total nitrogen, phosphorus and copper) in a humid Mediterranean catchment, emphasizing the importance of integrated approaches to define adaptive land management practices that can ensure the future sustainability of water resources in the region.