Project duration: 2016 to 2019
Due to frequently water-saturated soils, stream riparian zones have the ability to remove nitrate from river floodplain systems based upon the carbon and nitrate availability along with the long hydraulic retention time. However, the controlling factors and the dimension of nitrate degradation potential are still largely unknown. The reason for this is (1) the high complexity of the denitrification process with a large number of possible influencing factors and (2) the high spatial and temporal heterogeneity of influencing factors.
The statistical correlations between spatial and physicochemical parameters of the soil shall be identified, along with the experimentally determined results, based on the results of the acetylene inhibition. Special attention is paid to those parameters that are widely available and hence can be used directly or indirectly via proxies to estimate the level of self-purification of floodplains. Based on the identified statistical correlations, model-based prediction of the denitrification capacity of entire floodplains should be optimized. In order to assess the societal benefits of the purification performance as an ecosystem service of floodplains, it is finally subjected to an economic evaluation.
Important objectives of the project
- Determination of the denitrification capacity in floodplains of different hydro-geomorphological units, which are representative for active floodplains of federal waterways namely Elbe, Rhine, Main, and Weser.
- Analysing the effects of hydrological parameters (i.e. flood duration, connectivity) and soil parameters (i.e. soil type, soil organic matter, pH, temperature) as well as topography on potential denitrifications rates.
- Validation, adaptation and extension of the existing thumb-rule approach by Schulz-Zunkel et al. (2012) and Horchler et al. (2015).
- Development of a denitrification model in the context of ecosystem services.
- Evaluating the potential of purification through denitrification as an ecosystem service.