Welcome to NiCA
- a research project on nitrate reduction in geologically heterogeneous catchments
The NiCA project ended in 2014. To learn more about the results from the work, you can have a look at the list of publications
etc. produced during the project.
Nitrate leaching from agricultural areas is one of the major water resources management problems in Denmark. The efficiency of the existing general regulations is in average only 1/3, because 2/3 of the nitrate leaching from the root zone is reduced in the subsurface before reaching the streams. Today it is impossible to differentiate between vulnerable areas from where nitrate leaching reaches the surface water with very little reduction and robust areas where almost all leached nitrate is reduced. This is a serious constraint for designing cost-effective water management measures.
In NiCA, we have developed tools for assessing nitrate reduction in the subsurface between the root zone and the streams and methodologies for assessing at which spatial scales such tools have predictive capabilities. A new instrument for airborne geophysical measurements, MiniSkyTEM, dedicated for identifying geological structures and heterogeneities in the upper 30 m has also been developed. Furthermore, a new geophysical method, MRS, has been introduced, and these two geophysical methods have been tested against field data. State-of-the-art and novel hydrological models (DAISY, MIKE SHE/MIKE11, HydroGeoSphere, RWHET) were applied, and the effect of geological heterogeneity was analysed by use of stochastic geological realisations using TProGS. A new concept, Representative Elementary Scale (RES)for assessing the minimum scale at which models, with a given data input, potentially have predictive capabilities has also been introduced. All studies were conducted in a 5 km2, densely instrumented catchment (Lillebæk), and tested in a 100 km2 catchment (Norsminde Fjord), where farmers and authorities were actively involved in evaluating possible measures for reducing the nitrate load to surface water in a cost-effective manner. Finally, the economic gain from a cost efficient location of the measures was evaluated.
The NiCA project started 1 January 2010 and ran for five years until the end of 2014. Five research groups (including one Canadian), one GTS institute, four Danish consulting companies (including two SMEs), and two Danish public authorities were involved in the project, that was partly funded by the Danish Council for Strategic Research