Nitrate reduction in geologically heterogeneous catchments — A framework for assessing the scale of predictive capability of hydrological models

Testing alternative uses of electromagnetic data to reduce the prediction error of groundwater models

“…This is particularly true for data collected by airborne electromagnetic methods (AEM) because they can be collected quickly, densely, and at a relatively low cost for the very large spatial coverage (Steuer et al, 2008;Viezzoli et al, 2010b;Abraham et al, 2012;Faneca Sànchez et al, 2012;Refsgaard et al, 2014;Munday et al, 2015). Large-scale AEM (or ground-based EM) investigations have been used to delineate aquifers, aquitards, and buried valleys or other structures containing aquifers Jørgensen et al, 2003;Abraham et al, 2012;Oldenborger et al, 2013), to assess aquifer vulnerability Foged et al, 2014), to map saltwater intrusion (Fitterman and Deszcz-Pan, 1998;Viezzoli et al, 2010b;Lawrie et al, 2012;Herckenrath et al, 2013b), and to map freshwater resources (Steuer et al, 2008;Faneca Sànchez et al, 2012;Munday et al, 2015).…”

Nitrogen and phosphorus transformations and balance in a pond-ditch circulation system for rural polluted water treatment

“…For example, it was applied to nutrient modeling at basin scale (Styczen and Storm, 1993), in pesticide simulation (Thorsen et al, 1998), nitrate leaching simulation (Refsgaard et al, 1999), physically based integrated modeling of nitrogen cycle in catchment scale (Hansen et al, 2009), nitrate reduction simulation in a complex geologically heterogeneous region (Refsgaard et al, 2014), phosphorus transport simulation in Everglades National Park (Long et al, 2015), and agrochemical transport simulation in an agriculture area (Kourgialas and Karatzas, 2015). However, compared to a large number of water movement simulations, the number of mass transport and water quality simulations is relatively smaller; this shows that the research and practices of fundamental water movement modeling have not being so numerous and proficient as to sufficiently sustain further research on water quality simulation.…”

Using a map-based assessment tool for the development of cost-effective WFD river basin action programmes in a changing climate

“…Danish studies have estimated that, on a national basis, about 2/ 3 of the nitrate leaching from the root zone is reduced naturally, through denitrification, in the subsurface before reaching surface waters (Refsgaard et al, 2014). In order to ensure the most costeffective fulfilment of the WFD, it is therefore recommended by the Danish Commission on Nature and Agriculture (2013) that agrienvironmental measures are spatially targeted to vulnerable areas where little or no retention takes place and the environmental effect consequently is the highest.…”

“…Since the late 1980s, several national action plans have been implemented in Denmark to reduce nitrogen (N) and phosphorous (P) loading to the aquatic environment. Nevertheless, further reductions of N loads to Danish estuaries are required during the implementation of the WFD to meet the objective of GES Refsgaard et al, 2014;Windolf et al, 2012). The first generation of Danish WFD RBMPs (2009e2015) has been considerably delayed, but in 2014 RBMPs for the 23 Danish river basins were adopted with catchment specific load targets for each estuary.…”

“…A major part of the estimated N load reductions necessary to meet the GES objective in the Danish estuaries has been postponed to the next WFD planning cycles (Danish Ministry of the Environment, 2010a; Danish Ministry of the Environment, 2014). Several Danish studies stress that future N reductions should be achieved through spatially targeted and river basin tailored action programmes (Commission on Nature and Agriculture, 2013; Dalgaard et al, 2014;Kronvang et al, 2008;Refsgaard et al, 2014;Windolf et al, 2012), where agricultural management practises in robust areas can be optimised. The most vulnerable agricultural areas (drained low lying soils), on the other hand, can be converted to less intensive agriculture or taken out of production.…”