Nutrients

(Model tools: DENUZ-WEKU-MEPhos)

The achievement of the good qualitative status according to the requirements of the EU Nitrates Directive, the EU Water Framework Directive (EU-WFD) and the Marine Strategy Framework Directive (EU-MSFD) is unclear, or rather unlikely in many regions due to excessive nutrient inputs. Against this background simulation models like the reactive N-transport models DENUZ/WEKU (Wolters et al, 2022; Kunkel et al., 2017, Wendland et al., 2009) and the P-transport model MEPhos (Tetzlaff & Wendland, 2012; Tetzlaff et al., 2009) have been developed.

The models display a high spatial resolution (e.g. 100m x 100m) and consider up to six diffuse N and P input pathways and up to five point source nutrient inputs.

Model analyses include the determination of the actual nitrogen and phosphorous pollution loads, the identification of "hot spot" areas for the introduction of nutrient reduction measures, the determination of nutrient reduction levels necessary to reach quality targets for groundwater and surface waters and the prediction of the impact of nutrient reduction measures.

Knowledge transfer and outreach:

Model results support the preparation of river basin management plans and programs of measures according to the requirements of the EU Water Framework Directive and the Marine Strategy Framework Directive on national level and in State Agencies of the Federal German States Hamburg, Hessen, Mecklenburg-Vorpommern, Niedersachsen, Nordrhein-Westfalen, Rheinland-Pfalz, Sachsen-Anhalt, Schleswig-Holstein and Thüringen as well as and in Republic of Slovenia.

Since September 2022, nationwide nutrient modeling is carried out in the RELAS project, which is being worked on jointly with the Thünen Institute of Rural Studies (Braunschweig) and the Leibniz Institute of Freshwater Ecology and Inland fisheries (Berlin) on behalf of the BMEL. The aim of this project is to analyze whether the measures of the revised Fertilizer Ordinance (2020) are suitable for achieving the objectives of the EU Nitrate Directive (impact monitoring). The results of this project are included in the federal government's reporting to the EU Commission.

Key R&D projects:

Key publications:

· Wolters, T., Bach, T., Eisele, M., Eschenbach, W., Kunkel, R., McNamara, I., Well, R., Wendland, F. (2022): The derivation of denitrification conditions in groundwater: combined method approach and application for Germany. Ecological Indicators, Volume 144, 109564, ISSN 1470-160X, DOI.org/10.1016/j.ecolind.2022.109564.

· Eysholdt, M., Kunkel, R., Rösemann, C., Wendland, F., Wolters, T., Zinnbauer, M. & Fuß, R. (2022): A model based estimate of nitrate leaching in Germany for GHG reporting. Journal of Plant Nutrition and Soil Science,1–14, DOI.org/10.1002/jpln.202200119.

· Wolters, T., Cremer, N., Eisele, M., Herrmann, F., Kreins, P., Kunkel, R., Wendland, F. (2021): Checking the plausibility of modelled nitrate concentrations in the leachate on federal state scale in Germany.- Water, 13(2), 226, Doi.org/10.3390/w13020226.

· Kronvang, B., Wendland, F. Kovar, K., Fraters, D. (Eds.) (2020): Land Use and Water Quality.- Special issue Water, 12, 2412. 248 pages. ISBN 978-3-03943-503-6 (Hbk); ISBN 978-3-03943-504-3, DOI:org/10.3390/books978-3-03943-504-3.

· Wendland, F., Bergmann, S., Eisele, M., Gömann, H., Herrmann, F., Kreins, P., Kunkel, R. (2020): Model-Based Analysis of Nitrate Concentration in the Leachate—The North Rhine-Westfalia Case Study, Germany.- Water, 12(2), 550 [10.3390/w12020550].

· Ta, P., Tetzlaff, B., Trepel, M., Wendland, F. (2020): Implementing a Statewide Deficit Analysis for Inland Surface Waters According to the Water Framework Directive—An Exemplary Application on Phosphorus Pollution in Schleswig-Holstein (Northern Germany).- Water 12(5), 1365 [10.3390/w12051365].

· Schmidt, B., Kuhn, U., Trepel, M., Kreins, P., Zinnbauer, M., Eysholdt, M., Osterburg, B., Löw, P., Wendland, F., Herrmann, F., Kunkel, R., Tetzlaff, B., Wolters, T., Venohr, M., Nguyen, H. (2020): Modellansatz zur Bestimmung der Nährstoffbelastung und ihrer Reduktion in allen deutschen Flussgebieten.- Wasser und Abfall, 1-2, 33-38.

· He, Q., Wendland, F., Molkenthin, F. (2019): The analysis of nitrogen load and simulation uncertainty using SWAT in a catchment with paddy field in China.- Water Science and Technology, 80.4, 806-816, DOI: 10.2166/wst.2019.326.

· Eschenbach, W., Budziak, D., Elbracht, J., Höper, H., Krienen, L., Kunkel, R., Meyer, K., Well, R., Wendland, F. (2018): Möglichkeiten und Grenzen der Validierung flächenhaft modellierter Nitrateinträge ins Grundwassermit der N2/Ar-Methode.- Grundwasser – Zeitschrift der Fachsektion Hydrogeologie, 23(2):125-139, DOI:10.1007/s00767-018-0391-6.

· Kunkel, R., Herrmann, F., Kape, H.-E., Keller, L., Koch, F., Tetzlaff, B., Wendland, F. (2017): Simulation of terrestrial nitrogen fluxes in Mecklenburg-Vorpommern and scenario analyses how to reach N-quality targets for groundwater and the coastal waters.- Environmental Earth Science, 76(4):146, DOI 10.1007/s12665-017-6437-8.

· Heidecke, C., Ackermann, A., Kreins, P., Kuhr, P., Kunkel, R., Tetzlaff, B., Wendland, F., Mahnkopf, J., Venohr, M. (2016): Erreichbarkeit der Nährstoffreduzierungsziele in Niedersachsen fraglich.- Wasser & Abfall 18, 7/8, 21-25.

· Kuhn, U., Schmidt, B., Heidecke, C., Kreins, P., Ackermann, A., Wendland, F., Kunkel, R., Venohr, M., Mahnkopf, J. (2016): Nährstoffmanagement in der Flussgebietseinheit Weser im Spannungsfeld zwischen Wasserwirtschaft und Landwirtschaft - Ergebnisse des Projektes AGRUM+.- Korrespondenz Wasserwirtschaft, 9 (4), 216-225.

· Kunkel, R., Kape, H.-E., Keller, L., Koch, F., Tetzlaff, B., Wendland, F. (2016): Szenarien für die Reduzierung von Stickstoffeinträgen zum Erreichen der Grundwasser- und Meeresschutzziele in Mecklenburg-Vorpommern. – Hydrologie und Wasserbewirtschaftung, 60 (2), 119–134, DOI: 10.5675/HyWa_2016,2_2.

· Tetzlaff, B., Bock, A., Krause, D., Marowsky, K. (2015): Eutrophierungsprobleme im Altmühlsee als Folge diffuser und punktförmiger P-Einträge – 2. Managementoptionen zur Verringerung der Gewässerbelastung.- Korrespondenz Wasserwirtschaft, 8(5), 284-289, DOI: 10.3243/kwe2015.05.002.

· Tetzlaff, B., Krause, D., Marowsky, K., Bock, A. (2015): Eutrophierungsprobleme im Altmühlsee als Folge diffuser und punktförmiger P-Einträge – Modellierung und Ergebnisse.- Hydrologie und Wasserbewirtschaftung, 59(1), 23-36, DOI: 10.5675/HyWa_2015,1_2.

· Andelov, M., Kunkel, R., Uhan,J. & Wendland, F. (2014): Determination of nitrogen reduction levels necessary to reach groundwater quality targets in Slovenia.- Journal of Environmental Sciences, 29-9, 1806-1818, DOI: 10.1016/j.jes.2014.06.027.

· Celen, M., Karpuzcu, M., Engin, G., Tetzlaff, B., Wendland, F. (2014): Modelling of the Total Phosphorus Input Pathways in Porsuk Reservoir Catchment in Turkey.- Environmental Earth Sciences, 72 (12): 5019–5034, DOI:10.1007/s12665-014-3371-x.

· Wendland, F., Heidecke, C., Keller, L., Kreins, P., Kuhr, P., Tetzlaff, B., Trepel, M., Wagner, A. (2014): Räumlich differenzierte Quantifizierung der Stickstoffeinträge ins Grundwasser und die Oberflächengewässer in Schleswig-Holsteins.- Korrespondenz Wasserwirtschaft 6/14, 327-332.

· Tetzlaff, B., Haider, J., Kreins, P., Kuhr, P., Kunkel, R., Wendland, F. (2013): Grid-based modelling of nutrient inputs from diffuse and point sources for the state of North Rhine-Westphalia (Germany) as a tool for river basin management according to EU-WFD.- River Systems, 20/3–4, 213–229, DOI: 10.1127/1868-5749/2013/0060.

· Kuhr, P., Haider, J., Kreins, P., Kunkel, R., Tetzlaff, B., Vereecken, H., Wendland, F. (2013): Model Based Assessment of Nitrate Pollution of Water Resources on a Federal State Level for the Dimensioning of Agro-environmental Reduction Strategies: The North Rhine-Westphalia (Germany) Case Study. - Water Resources Management, 27(3), 885-909, DOI: 10.1007/s11269-012-0221-z.

· Hirt, U., Kreins, P., Kuhn, U., Mahnkopf, J., Venohr, M., Wendland, F. (2012): Management options to reduce future nitrogen emissions into rivers: A case study of the Weser river basin, Germany.- Agricultural Water Management, 115, 118-131, DOI: 10.1016/j.agwat.2012.08.005.

· Tetzlaff, B., Wendland, F. (2012): Modelling sediment input to surface waters for Ger-man states with MEPhos: Methodology, sensitivity and uncertainty.- Water Resources Management, 26-1,165-184, DOI: 10.1007/s11269-011-9911-1.

· Tetzlaff, B., Friedrich, K., Vorderbrügge, T., Vereecken, H., Wendland, F. (2011): Distributed modelling of mean annual soil erosion and sediment delivery rates to surface waters.- Catena, 102, 13-20, DOI:10.1016/j.catena.2011.08.001.

· Kunkel, R., Kreins, P., Tetzlaff, B., Wendland, F. (2010): Forecasting the effects of EU policy measures on the nitrate pollution of groundwater and surface waters.- Journal of Environmental Sciences, 22 (6),872-877, DOI: 10.1016/s1001-0742(09)60191-1.

· Wendland, F., Behrendt, H., Hirt, U., Kreins, P., Kuhn, U., Kuhr, P., Kunkel, R., Tetzlaff, B. (2010): Analyse von Agrar- und Umweltmaßnahmen zur Reduktion der Stickstoffbelastung von Grundwasser und Oberflächengewässer in der Flussgebietseinheit Weser.- Hydrologie und Wasserbewirtschaftung, 54 (4), 231 – 244.

· Wendland, F., Jahnke, C., Kunkel, R., Meier, K., Schmalenstroer, M., Schütz., C., Voigt, H.-J. (2010): Zur Beziehung zwischen Nmin – Gehalt im Boden und Nitratkonzentration im oberflächennahen Grundwasser.- GWF-Wasser/Abwasser, 384-393.

· Tetzlaff, B., Hake, J.-F., Vereecken, H., Wendland, F. (2010): Sustainable use of water resources in Europe and the role of integrated modelling of phosphate fluxes.- International Journal of Global Environmental Issues, 10,1/2, 172 – 193.

· Tetzlaff, B., Vereecken, H., Kunkel, R., Wendland, F. (2009): Modelling phosphorus inputs from agricultural sources and urban areas in river basins. Environmental Geology, 57, 183-193, https://link.springer.com/article/10.1007%2Fs00254-008-1293-1.

· Wendland, F., Behrendt, H., Gömann, H., Hirt, U., Kreins, P., Kuhn, U., Kunkel, R., Tetzlaff, B. (2009): Determination of nitrogen reduction levels necessary to reach groundwater quality targets in large river basins: the Weser basin case study, Germany. Nutrient Cycling in Agroecosystems, 85 (1), 63-78, DOI:10.1007/s10705-009-9248-9.

· Kunkel, R., Eisele, M., Wendland, F: (2008): Assessing necessary nutrient reduction for measurement planning in groundwater bodies. Water Science and Technology, 58 (12), 2295-2302, DOI: 10.2166/wst.2008.821.

· Kunkel, R., Tetzlaff, B., Gömann, H., Kreins, P., Wendland, F. (2008): Water fluxes and diffuse nitrate pollution at the river basin scale – Interfaces for the coupling of agroeconomic models with hydrologic models. European Water Journal, 17/18, 29-40.

· Kunkel, R., Eisele, M., Schäfer, W., Tetzlaff, B., Wendland, F. (2008): Planning and implementation of nitrogen reduction measures in catchment areas based on a determination and ranking of target areas. Desalination, 226, 1-12, DOI:10.1016/j.desal.2007.01.231

· Montzka, C., Canty, M., Kreins, P., Kunkel, R., Menz, G., Vereecken, H., Wendland, F. (2008): Multispectral remotely sensed data in modelling the annual variability of nitrate concentrations in the leachate. Environmental Modelling & Software, 23 (8), 1070-1081, DOI.org/10.1016/j.envsoft.2007.11.010.

· Guse, B., Bronstert, A., Rode, M., Tetzlaff, B., Wendland, F. (2007): Application of two phosphorus models with different complexities in a mesoscale river catchment. Advances in Geosciences, 11, 77-84, https://doi.org/10.5194/adgeo-11-77-2007.

· Tetzlaff, B., Kreins, P., Kunkel, R., Wendland, F. (2007): Area-differentiated modelling of P-fluxes in heterogeneous macroscale river basins. Water Science and Technology, 55 (3), 123-131, DOI: 10.2166/wst.2007.080.

· Tetzlaff, B., Wendland, F. (2007): P-pollution in a heavily urbanized river basin from point and diffuse sources - the River Ruhr case study (Germany). Water Science and Technology, 56 (1), 29-37, DOI: 10.2166/wst.2007.433.

· Tetzlaff, B., Kunkel, R., Schäfer, W., Wendland, F. (2007): Determination and ranking of target areas in catchments for the implementation of nitrogen reduction measures. Advances in Geosciences, 11, 69-75, https://doi.org/10.5194/adgeo-11-69-2007.

· Wendland, F., Kunkel, R., Gömann, H., Kreins, P. (2007): Water fluxes and diffuse nitrate pollution at the river basin scale: Interfaces for the coupling of agroeconomical models with hydrological approaches. Water Science and Technology, 55 (3), 133-142, DOI: 10.2166/wst.2007.081.

· Kreins, P., Gömann, H., Herrmann, S., Kunkel, R., Wendland, F. (2007): Integrated agricultural and hydrological modelling within an intensive livestock region. Advances in the Economics of Environmental Resources, 7, 113-143, DOI:10.1016/S1569-3740(07)07006-X.

· Gömann, H., Kreins, P., Kunkel, R., Wendland, F. (2005): Model based impact analysis of policy options aiming at reducing diffuse pollution by agriculture - a case study for the river Ems and a sub-catchment of the Rhine. Environmental Modelling & Software, 20, 261-271, https://doi.org/10.1016/j.envsoft.2004.01.004.

· Kunkel, R., Bogena, H., Gömann, H., Kreins, P., Wendland, F. (2005): Management of regional German river catchments (REGFLUD) - impact of nitrogen reduction measures on the nitrogen load in the River Ems and the River Rhine. Water Science and Technology, 51, 291-299, DOI:10.2166/wst.2005.0603.

· Wendland, F., Bogena, H., Gömann, H., Hake, J. F., Kreins, P., Kunkel, R. (2005): Impact of nitrogen reduction measures on the nitrogen loads of the river Ems and Rhine (Germany). Physics and Chemistry of the Earth, 30, 527-541, DOI:10.1016/j.pce.2005.07.007.

· Gömann, H., Kreins, P., Kunkel, R., Wendland, F. (2004): Model based impact analysis of policy options aiming at reducing diffuse pollution by agriculture: a case study for the river Ems and a sub-catchment of the Rhine. Environmental Modelling & Software, 20, 261-271, https://doi.org/10.1016/j.envsoft.2004.01.004.

· Kunkel, R., Bach, M., Behrendt, H., Wendland, F. (2004): Groundwater-borne nitrate intakes into surface waters in Germany. Water Science and Technology, 49, 11-19, DOI:10.2166/wst.2004.0152.

· Wendland, F., Kunkel, R., Voigt, H. J. (2004): Assessment of groundwater residence times in the pore aquifers of the River Elbe Basin. Environmental Geology, 46, 1-9, DOI:10.1007/s00254-004-1013-4.

· Gömann, H., Kreins, P., Kunkel, R., Wendland, F. (2003): Koppelung agrarökonomischer und hydrologischer Modelle. Agrarwirtschaft, 52, 195-203, DOI: 10.22004/ag.econ.98360.

· Narula, K. K., Bansal, N. K., Gosain, A. K., Wendland, F. (2003): Area-differentiated modelling of excess nutrient and contaminant leaching risks at the river-basin scale using a hydrological approach in India. International Journal of Environment and Pollution, 19, 225-242, DOI: 10.1504/IJEP.2003.003317.

· Wendland, F., R. Kunkel, A. Grimvall, B. Kronvang & D. I. Muller-Wohlfeil (2002): The SOIL-N/WEKU model system - a GIS-supported tool for the assessment and management of diffuse nitrogen leaching at the scale of river basins. Water Science and Technology, 45, 285-292, DOI: 10.2166/wst.2002.0260.

· Müller-Wohlfeil, D. I., B. Kronvang, S. E. Larsen, N. B. Ovesen & F. Wendland (2001): Establishment of a harmonized tool for calculating river discharge and nitrogen loads from unmonitored areas in Denmark. Physics and Chemistry of the Earth, Part B-Hydrology Oceans and Atmosphere, 26, 617-622.

· Wendland, F., R. Kunkel, A. Grimvall, B. Kronvang & D. I. Muller-Wohlfeil (2001): Model system for the management of nitrogen leaching at the scale of river basins and regions. Water Science and Technology, 43, 215-222, https://doi.org/10.2166/wst.2001.0428.

· Kunkel, R., F. Wendland & H. Albert (1999): Zum Nitratabbau in den grundwasserführenden Gesteinsschichten des Elbeeinzugsgebietes. Wasser und Boden, 51, 16-19.

· Wendland, F., M. Bach & R. Kunkel (1998): The influence of nitrate reduction strategies on the temporal development of the nitrate pollution of soil and groundwater throughout Germany - a regionally differentiated case study. Nutrient Cycling in Agroecosystems, 50, 167-179, DOI:10.1023/A:1009736227245.

· Wendland, F. (1994): Modelling the nitrate flow in the groundwater provinces of the "old" federal states of the Federal Republic of Germany. Ecological Modelling, 75, 385-397, DOI: 10.1016/0304-3800(94)90034-5.

· Wendland, F., H. Albert, M. Bach & R. Schmidt (1994): Potential nitrate pollution of groundwater in Germany: a supraregional differentiated model. Environmental Geology, 24, 1-6, https://doi.org/10.1007/BF00768070.

· Wendland, F., H. Albert, M. Bach & R. Schmidt (1994): Atlas zum Nitratstrom in der Bundesrepublik Deutschland. Deutsche Gewässerkundliche Mitteilungen, 37-41.