Small unmonitored near‐coastal catchment areas yielding large mass loading to the sea

Abstract

[1] Continental freshwater transports and loads excess nutrients and pollutants from various land surface sources into downstream inland and coastal water environments. This study shows that even small, hydrologically unmonitored near-coastal catchment areas may generate large nutrient and pollutant mass loading to the sea of a magnitude similar to or greater than monitored river loads. Systematic near-coastal gaps in the monitoring of freshwater discharges to the sea may therefore mislead the quantification of coastal mass loading significantly. A methodology is presented for quantifying the mass load contributions of all the different unmonitored pathways of hydrological mass transport to the coast, including unmonitored river parts, whole unmonitored streams, and submarine groundwater discharge. This can be used for guiding future efforts to improve monitoring so that it includes the essential hydrological pathways of nutrient and pollutant loading to the sea.

Relevance of Hydro-Climatic Change Projection and Monitoring for Assessment of Water Cycle Changes in the Arctic

“…In contrast to this need, we found here that the supply of such time series is declining and mostly so in basins where the greatest temperature, and in particular, precipitation changes, are expected. Analogous biases in hydrological monitoring have also been reported for other parts of the world, in studies showing gaps prevailing most in the hotspots of greatest population and other water pollution pressures (Hannerz and Destouni 2006;Destouni et al 2008). Such results converge with the present in indicating an increasing need to identify and prioritize relevant hydrological monitoring for observing climate and environmental change in the Arctic and worldwide.…”

Diffuse hydrological mass transport through catchments: scenario analysis of coupled physical and biogeochemical uncertainty effects

“…Malmström et al, 2004Malmström et al, , 2008Darracq and Destouni, 2007;Cunningham and Fadel, 2007;Jardine, 2008) -the errors of mass transport measurements implied by the chosen measurement methods and the coverage gaps between the chosen measurement points in time and space (e.g. Hannerz and Destouni, 2006;Beven, 2006;Jarsjö and Bayer-Raich, 2008;Destouni et al, 2008) -the chosen model resolutions and possible neglect of potentially important contributing mass transport processes at different scales (e.g. Lindgren and Destouni, 2004;Refsgaard et al, 2006;Destouni et al, 2006;Ganoulis, 2009).…”

On the scope and management of pesticide pollution of Swedish groundwater resources: The Scanian example

“…Such studies are currently hampered by a lack of comprehensive and consistent data on pesticide occurrence in Swedish groundwater, resulting from nationally deficient statutory monitoring of anthropogenic pollutants in groundwater (Destouni et al 2008;Baresel and Destouni 2009). …”

“…In order to secure WFD compliance and thereby also future groundwater quality, Sweden further needs to develop and implement statutory regulations enforcing adequate monitoring and assessment of the occurrence of not only pesticides but, as previously noted, also other anthropogenic pollutants (Destouni et al 2008;Baresel and Destouni 2009;European Commission 2012;SEPA 2013) in groundwater nationwide. As for general groundwater quality monitoring and assessment, precepts effectively already exist (e.g.…”

“…However, to thoroughly assess the character and cause of pesticide pollution of Scanian, and effectively overall Swedish groundwater resources, is challenging due to a nationwide lack of comprehensive and consistent long-term groundwater monitoring data relevant to anthropogenic pollution concerns. This monitoring deficiency has previously been highlighted in relation to nutrient and pollutant loads in coastal areas (Destouni et al 2008), with regards to heavy metal drainage from mining areas (Baresel and Destouni 2009), and more recently in view of general groundwater status and quality assessment in accordance with national environmental objectives and the WFD (European Commission 2012; SEPA 2013). Basically, the national groundwater monitoring network as set up and maintained by the national groundwater authority (SGU; the Geological Survey of Sweden), focuses on areas with minimal human impact to constrain background/reference conditions and does not involve pesticide analyses (Nordberg and Persson 1974;SGU 2013a).…”