Chapter 12. The Impact of the Changing Climate on the Flux of Dissolved Organic Carbon from Catchments

Recent increases in dissolved organic carbon (DOC) concentrations in surface waters across both Europe and North America have focused attention on the factors controlling the export of DOC compounds from catchments.Waters containing high concentrations of DOC generally have a characteristic brown colour and are associated with the presence of highly organic soils. High DOC concentrations have implications for both water treatment and for the ecology of surface waters. DOC must be removed from drinking water because of health concerns related to the formation of trihalomethanes (THMs), carcinogenic compounds that are produced when water with a high DOC concentration is disinfected using chlorine (WHO, 2005). During the 1990s many water treatment plants in Nordic countries began to report an increased difficulty in treating highly coloured water (Löfgren et al., 2003; NORDTEST, 2003). Of particular concern has been the continued investment required to deal with the problem and indications that the quality as well as the quantity of organic matter appears to be changing (NORDTEST, 2003). Similar problems have been noted in the UK (Scott et al., 2001; Sharp et al., 2006). Changes in DOC concentration and water colour also have physical, chemical, and biological implications for lake ecosystems (Jones, 1998) while the export of DOC from catchments also represents a transfer of carbon from long-term terrestrial stores to more labile forms that can further contribute to atmospheric concentrations of CO2 and, therefore, potentially contribute to global warming. In this chapter the influence of climatic factors on short-term variability and long-term trends in the export of DOC is described using examples from CLIME catchments and from other published studies. A related chapter (Chapter 13 of this volume) describes the model simulations that were used to quantify the future flux of DOC at CLIME sites given the climate change projections summarised in Chapter 2.

JENNINGS Eleanor;  JARVINEN Marko;  ALLOTT Norman;  ARVOLA Lauri;  MOORE Karen;  NADEN Pam;  NIC AONGUSA Caitriona;  NOGES Tiina;  WEYHENMEYER Gesa; 

2010-01-26

Springer Science+Business Media B.V.

JRC54775

978-90-481-2945-4,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC54775,   

10.1007/978-90-481-2945-4_12,