| Title | Climate Change Impacts on Sediment Quality of Subalpine Reservoirs: Implications on Management |
| Abstract | Reservoirs are characterized by accumulation of sediments where micropollutants may
concentrate, with potential toxic effects on downstream river ecosystems. However, sediment
management such as flushing is needed to maintain storage capacity. Climate change is expected to
increase sediment loads, but potential effects on their quality are scarcely known. In this context,
sediment contamination by trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and organics
(Polycyclic Aromatic Hydrocarbons PAHs, Polychlorinated Biphenyls PCBs and C > 12
hydrocarbons) was analyzed in 20 reservoirs located in Italian Central Alps. A strong As and a
moderate Cd, Hg and Pb enrichment was emphasized by Igeo, with potential ecotoxicological risk
according to Probable Effect Concentration quotients. Sedimentation rate, granulometry, total
organic carbon (TOC) and altitude resulted as the main drivers governing pollutant concentrations
in sediments. According to climate change models, expected increase of rainfall erosivity will
enhance soil erosion and consequently the sediment flow to reservoirs, potentially increasing coarse
grain fractions and thus potentially diluting pollutants. Conversely, increased weathering may
enhance metal fluxes to reservoirs. Increased vegetation cover will potentially result in higher TOC
concentrations, which may contrast contaminant bioavailability and thus toxicity. Our results may
provide elements for a proper management of contaminated sediments in a climate change scenario
aiming at preserving water quality and ecosystem functioning. |
| Source | Water (Basel) 9 (680) |
| Keywords | dams; trace metals; contaminated sediments; desiltation; sedimentation rate |
| Journal | Water (Basel) |
| Editor | Molecular Diversity Preservation International, Basel, |
| Year | 2017 |
| Type | Articolo in rivista |
| DOI | 10.3390/w909068 |
| Authors | Marziali Laura 1,*, Gianni Tartari 1, Franco Salerno 1, Lucia Valsecchi 1, Clara Bravi 2, Erika Lorenzi 3, Pietro Genoni 3 and Licia Guzzella 1 |
| Text | 375342 2017 10.3390/w909068 dams; trace metals; contaminated sediments; desiltation; sedimentation rate Climate Change Impacts on Sediment Quality of Subalpine Reservoirs Implications on Management Marziali Laura 1, , Gianni Tartari 1, Franco Salerno 1, Lucia Valsecchi 1, Clara Bravi 2, Erika Lorenzi 3, Pietro Genoni 3 and Licia Guzzella 1 1 CNR IRSA, Water Research Institute, Via del Mulino, 19, I 20861 Brugherio MB , Italy; 2 Lombardy Region, Piazza Citta di Lombardia, 1, I 20124 Milano, Italy; 3 Lombardy Regional Environmental Protection Agency, Via Rosellini, 17, I 20124 Milano, Italy; Reservoirs are characterized by accumulation of sediments where micropollutants may concentrate, with potential toxic effects on downstream river ecosystems. However, sediment management such as flushing is needed to maintain storage capacity. Climate change is expected to increase sediment loads, but potential effects on their quality are scarcely known. In this context, sediment contamination by trace elements As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn and organics Polycyclic Aromatic Hydrocarbons PAHs, Polychlorinated Biphenyls PCBs and C > 12 hydrocarbons was analyzed in 20 reservoirs located in Italian Central Alps. A strong As and a moderate Cd, Hg and Pb enrichment was emphasized by Igeo, with potential ecotoxicological risk according to Probable Effect Concentration quotients. Sedimentation rate, granulometry, total organic carbon TOC and altitude resulted as the main drivers governing pollutant concentrations in sediments. According to climate change models, expected increase of rainfall erosivity will enhance soil erosion and consequently the sediment flow to reservoirs, potentially increasing coarse grain fractions and thus potentially diluting pollutants. Conversely, increased weathering may enhance metal fluxes to reservoirs. Increased vegetation cover will potentially result in higher TOC concentrations, which may contrast contaminant bioavailability and thus toxicity. Our results may provide elements for a proper management of contaminated sediments in a climate change scenario aiming at preserving water quality and ecosystem functioning. 9 Published version http //www.mdpi.com/2073 4441/9/9/680/pdf 07/09/2017 Articolo in rivista Molecular Diversity Preservation International 2073 4441 Water Basel Water Basel Water Basel Water. Basel lucia.valsecchi VALSECCHI LUCIA gianni.tartari TARTARI GIANNI liciamaria.guzzella GUZZELLA LICIA MARIA franco.salerno SALERNO FRANCO laura.marziali MARZIALI LAURA TA.P02.031.002 Impatti dei cambiamenti climatici sugli ecosistemi remoti DTA.AD002.552.001 Invasi Regione Lombardia |
