| Folie 1 Assessment of diffuse sources for pollution Meeting of the Working Group "Statistics of the Environment“ Sub-Group "Water“ October 2007 Luxembourg Katharina Lenz

| Folie 2 Contents Relevance of diffuse sources The EUROHARP-project Overview of different models Modeling of diffuse sources of heavy metals Summary & conclusion

| Folie 3 Diffuse sources /point sources Point sources Diffuse sources Diffuse sources are of high relevance !

| Folie 4 Diffuse sources /point sources in the Danube River Basin Danubs - project: Nutrient Fluxes in the Danube Basin Insitute for Water Quality and Waste management, Vienna University of Technology (2005). Nutrient Management in the Danube and ist Impact on the Black Sea, Final Report

| Folie 5 Relevance of diffuse sources EEA (2005). Source apportionment of nitrogen and phosphorus inputs into the aquatic environment, EEA- Report No7/2005

| Folie 6 Diffuse sources - Background Diffuse pollution cannot be measured, it has to be modeled! Validation of model with measured values at monitoring sites (monitoring networks) Water Framework Directive (WFD): harmonised tools/ methodologies to quantify nutrient losses from diffuse sources Project EUROHARP ( Objective: Comparison of different catchment scale modeling approaches for characterisation of the relative importance of point and diffuse pollution in surface freshwater systems Performance of 9 quantification tools in 17 European-wide river catchments Coordination: NIVA (Norvegian Institute for Water Research)

| Folie 7 EUROHARP

| Folie 8 EUROHARP QT no. Name of the QT Modelling institute Nutrients 1 NL - CATALTERRA(NL)[N, P] 2 Irish method-REALTAKMM (IRL)[P] 3 N-LESS NERI (DK)[N] 4 MONERIS FV-IGB (D)[N, P] 5 TRK (SOILN/HBV) SLU / SMHI (S)[N, P] 6 SWAT EC-JRC/NTUA (GR)/IRSA-CNR (I) [N, P] 7 EVENFLOW ADAS (UK)[N] 8 NOPOLU IFEN / BETURE-CEREC (F) [N, P] 9 Source apportionmentNERI (DK)[N, P] Process oriented, dynamic models: QT 1, 5, 6: dynamics of the fate of nutrient inputs in the soil are modelled in a two or three-dimensional way, often on a daily basis. Comprehensive representation of all individual system processes Semi-empiric models: QT 3, 4, 7: using a series of simpler, conceptual (semi-) empirical or statistical functions QT 2, 8, 9: do not consider soil processes, but can serve as “broad brush” tools to assess pollutant loads at catchment level.

| Folie 9 EUROHARP: 17 catchments Austria: Gurk catchment MONERIS SWAT NOPOLU Source apportionment Catchment area: 2.602km 2 Elevation Range: m Rainfall: 905 mm Arable land: ha Grassland: ha Forest: ha (55%) Lakes: 17 (>2 ha) Inhabitants: River Course Length: 150 km

| Folie 10 EUROHARP: N Balance for the Gurk Catchment per year t N/aSWATMONERISSA N-Input: Point sources Atmospheric deposition on water bodies Loss from woodland and other non- agricultural land Loss from agricultural land Total N-Input N-Output: Load Retention Total N-Output

| Folie 11 EUROHARP: P Balance for the Gurk Catchment per year t P/aSWATMONERISSA P-Input: Point Sources Atmospheric deposition on water bodies 20,4 Loss from woodland and other non- agricultural land Loss from agricultural land Total P-Input P-Output: Load Retention Total P-Output

| Folie 12 EUROHARP-Catchment Gurk: Results ModelSWATMONERISNOPOLUSAmeasured values Total area (ha) Agricultural land (ha) Period:1995– – – –1999 Flow (Mio m 3 /y) –902 Load (t N/y) –2.165 Load (t P/y) –82

| Folie 13 MONERIS

| Folie 14 MONERIS: MOdeling Nutrient Emissions in RIver Systems 7 pathways: atmospheric deposition groundwater tile drainage paved urban areas erosion surface runoff (dissolved nutrients) discharges from point sources (municipal waste water treatment plants and industrial discharges) Basic input into the model: Data on river flow water quality ( GIS integrating digital maps (e.g. hydrogeo- logical maps, soil maps) statistical information (inhabitants, land use)

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| Folie 17 Phosphorus EinwohnerFläche Atmosphär -ische Deposition Abschwem- mung DränagenErosion Grund- wasser Punkt- quellen versiegelte urbane Flächen Gesamt Landwirt- schaftliche Aktivitäten PLR Nr. Planungs- raum [E][km²][t/a] 1Rhein Elbe Donau bis Jochenstein Donau unterhalb Jochenstein March Mur Drau Leitha, Raab und Rabnitz Gesamt Österreich ,6%24,4%0,2%41,9%10,9%17,5%4,4%100,0%36,6% MONERIS: Austrian example Phosphorus

| Folie 18 MONERIS model +: No model calibration needed Good applicability for catchments size ≥ 500 km 2 Representation of full N- and P-cycle Identification of emission pathways Consideration of retention processes in groundwater and surface water Scenario calculations possible -: Empirical approaches limited in their applicability (particularly for semi-arid regions) limited spatial distribution Uncertainty increases with decreasing catchment size limited temporal variations (5 years annual values) GIS data needed to parameterise the model

| Folie 19 SWAT

| Folie 20 SWAT SWAT: 3 dimensional/continous time watershed model that operates on a daily time step at basin scale. management & timing of agricultural practises  rivers Nitrogen processes in the soil described in SWAT

| Folie 21 SWAT Precipitation Irrigation Rain Snow Snow melt Surface Runoff Transmission Losses Infiltration Snow cover Soil Storage Soil Evaporation Plant Uptake and Transpiration Lateral Flow Percolation Soil Water routing (10 layers) Sreamflow Irrigation Diversion Transmission Losses Route to next Reach or Reservoir Shallow Aquifer Irrigatio n RevapSeepag e Return Flow Pond/ Reservoir Water Balance P/R Evaporation Irrigation P/R Outflow P/R Seepage Deep Aquifer Irrigation SWAT: hydrological processes

| Folie 22 SWAT model +: good representation of hydrological conditions (3 runoff components, ETR, snow melt…) spatial distribution of hydrologic characteristics diverse options for land management river chemistry comprehensive definition of soil characteristics calculation of components of N- and P-cycle, distinction between land and water phase Calculation on daily timestep -: model calibration in general Number of parameters to be calibrated on HRU-, subbasin- or basin-level definition of some hydrologic parameter not on same level (snow melt-basin level, soil-HRU, GW- subbasin) no connection between GW-recharge and baseflow for N-cycle (no scenario calcuations) Limitation in applicability regarding catchment area Erosion (P-emissions) decisively dependent on well calibrated surface runoff components

| Folie 23 NOPOLU NOPOLU: N-balance; N-surplus + transfer model dep. on soil characteristics  part of it to surface waters Nitrogen input balance used within NOPOLU

| Folie 24 SOURCE APPORTIONMENT Source apportionment (SA): based on the assumption: Total nitrogen and phosphorus loads at the selected river measurement site (Lriver) represent the sum of the nitrogen and phosphorus discharges from point sources (DP), the nitrogen and phosphorus losses from diffuse sources (LOD) and the natural background losses of nitrogen and phosphorus (LOB). Furthermore retention of nitrogen and phosphorus in the rivers is taken into account (R). LOD = Lriver - DP - LOB + R

| Folie 25 Applicability of models Main questions: - is the model valid for use under the specific catchment conditions being considered? - what is the temporal and spatial scale at which model output is required, and which chemical species need to be modelled? - what are the resource limitations (time and data costs) on a particular study (the models vary widely in their high or low data input requirements and time needed for model applications)

| Folie 26 Diffuse sources: Heavy metals Fuchs, S.; Scherer, U.; Hillenbrand, T.; Marscheider-Weidemann, F.; Behrendt, H.; Opitz, D. (2002): Emissions of Heavy Metals and Lindane into River Basins of Germany. UBA-Texte 55/02, Berlin, Germany

| Folie 27 Diffuse sources: Heavy metals Upgrade of nutrient models for application on heavy metal emissions MONERIS (Oltmann et al., 2003): addition of heavy metal typical transport processes and specific pathways to the basic module: historic mining activities shipping Update of input data concerning heavy metals Data inquiries to improve the input data are needed

| Folie 28 Summary & Conclusion  Diffuse sources represent an important source for nutrients and heavy metals into the aquatic environment  Calculation/ modeling of diffuse source pollution is an issue for water experts  ask at universities, ministries, water associations  Diffuse sources issue of WFD  contact administrative bodies responsible for WFD - implementation  Different models vary considerably as regards input data, complexity, resources needed and level of process representation  Choice of methodology/ model used individually based on requirements in a country

| Folie 29 Thank you for your attention!