Application of SWIM model in the Elbe basin: experience and new developments

Transcription

1 Application of SWIM model in the Elbe basin: experience and new developments Valentina Krysanova, Fred Hattermann, Joachim Post and Anja Habeck SWAT 25, Zürich Potsdam Institute for Climate Impact Research

2 Outline the model SWIM: an overview the case study basin model development: - new components and techniques, - new modules, - impact assessment: examples literature on SWIM and applications

3 SWIM (Soil and Water Integrated Model) scheme Climate: Global radiation, temperature, precipitation Hydrological cycle Nitrogen cycle Soil profile A B C Vegetation/ Crop growth LAI Bio mass N-NO 3 N o-ac N o-st N res Phosphorus cycle SWIM was developed in PIK (Potsdam) based on SWAT-93 and MATSALU for climate and land use change impact studies Upper ground water Lower ground water Roots Land use pattern P lab P m-ac P m-st & land management P org P res

4 Case study area: the Elbe basin Basin: drainage area km² long-term mean annual precipitation 659 mm agriculture areas: 56 % River: total length 192 km long-term mean discharge at the mouth 716 m 3 s -1 specific discharge 6.2 l s -1 km -2 or 29.7 % of annual precipitation City Arable land Grassland Forest Mining Wetlands Water Hamburg Berlin

5 SWIM development: new components and techniques Important! The average subbasin size is essential both for lowland basins (accumulation time) and for mountainous basins (climate interpolation). 3-level disaggregation is included explicitely, resulting maps can be printed for hydrotopes or HRUs (VK), preprocessing: climate interpolation using four methods, elevation can be considered (FH), crop generator (FH, JP), validation technique: multi-scale, multi-site, and multicriteria (all), uncertainty analysis technique (FH).

6 Climate Interpolation example: mean temperature Inverse distance Eff=.25 Thiessen polygons Eff= -.24 Climate stations Ordinary kriging Eff=.29 External drift kriging Eff=.67 Important! Climate interpolation is especially needed: 1. for precipitation, 2. in mountainous basins, 3. if the number of stations is low.

7 Crop generator: examples for the reference and scenario periods Important! clover / alfalfa clover / alfalfa rape rape potatoe potatoe sugar beet sugar beet silage maize silage maize summer barley summer barley winter barley winter barley winter rye winter rye winter wheat winter wheat fellow land fellow land Crop rotations affect both water and nutrient dynamics, and therefore should be adequately represented. a Crop distribution: reference (example) Crop distribution: scenario (example)

8 Validation technique: examples + large scale + g-w + crop +erosion + N, P Important! First: model understanding and experience in manual calibration, Then: automatic calibration 1 Lowland 2 Loess 3 Mountains 1: Stepenitz, 576 km 2, North. Pleistocen Efficiency:.73 2: Upper Mulde, 291 km 2, Mountains / Loess Efficiency:.77 3: Upper Saale, 113 km 2, Thüringer Wald, Efficiency:.82

9 Uncertainty analysis mount. loess lowland Histograms of N&S efficiency and % error assuming a stochastic choice of parameters Elbe basin mount. Summary: N&S is better in mountainous basins and at the large scale; % error is lower in mountainous basins. Simulation results in the loess basins could be improved by appliying better soil parametrization. loess lowland Elbe basin

10 SWIM development: new modules Riparian zone module in SWIM: SWIM-rip model version (Fred Hattermann et al.) Carbon module included explicitely in SWIM: SWIM-SCN model version (Joachim Post et al.)

11 SWIM-rip concept: Water fluxes at the catchment scale and the role of riparian zone Riparian zone serves as an interface between upland and river network (or: between subbsins and streams), 1) It interacts with groundwater, 2) lateral fluxes from upland pass through riparian zone

12 SWIM-rip concept: Water fluxes at the catchment scale and the role of riparian zone Model definition: A riparian zone or wetland is defined as a hydrotope with shallow g-w table, where plant roots can reach groundwater, and having lateral inflow from upland areas Three main changes introduced in the model: A. implementation of daily groundwater table dynamics at the hydrotope level and soil-groundwater interaction, B. implementation of nutrient retention in groundwater and interflow (mainly through denitrification), C. implementation of water and nutrient uptake by plants from groundwater in riparian zones and wetlands.

13 The effect of additional N uptake in riparian zones on N concentrations in the river N plant uptake [kg/ha] Additional uptake [kg/ha] river nitrate concentration with uptake in riparian zones.4 Attention! [mg/l] without uptake in riparian zones uptake by plants difference difference [mg/l] More details in Fred Hattermann s presentation /1/93 7/1/93 1/1/94 7/1/94 1/1/95 7/1/95 1/1/96 7/1/96 1/1/97 7/1/97 1/1/

14 SWIM-SCN model version: the concept C/N turnover pools: POM, AOM and mineral pools 5 POM fractions for each plant species first order reaction kinetics, depending on soil moisture, soil temperature Important! The level of complexity of the new carbon module is compatible with those of other SWIM modules Soil processes Vegetation Proc esses Vegetation Land use Land growth management Soil Water Soil C, N turnover Soil Temp. Litter produc tion C in POM Qpom N in POM Hydrologic al Proc esses lateral and vertic al Uptake of water & nutrients k 2 k 1 Qaom k * 1 C in AOM N in AOM k * 2 k aom k aom mineral C Atmosphere Meteorology Deposition C O 2 k nit NH 4 NO 3 perc olation leac hed of water N

15 SWIM-SCN model version: verification Soil respiration [gc/m2 d] 2. M easured soil respiration (Field plots of ATB) 1.6 Sim ulated soil respiration [g C /m 2 d] Heterotrophic soil respiration Field plots ATB Potsdam, Germany sandy soil, wheat rye rotation quick warming and cooling of sandy soil in spring / autumn causes a shift in simulations 3 Corg content [%], - 2 cm soil depth measured Corg content, unfertilized field plot measured Corg content, fertilized field plot simulated Corg content, unfertilized field plot simulated Corg content, fertilized field plot Linear (measured Corg content, unfertilized field plot) Linear (measured Corg content, fertilized field plot) Long term simulation (192 22) Field plots UFZ Bad Lauchstädt, Saxony-Anhalt, Germany silty-loamy soil, high fertility 4 year crop rotation 2 fertilisation regimes

16 Effect of crop rotations on long term soil C dynamics Bad Lauchstädt experimental site ( ) original grain_maize grain_maize_cov grain_root grain_root_cov 4grain 2 gras 2grain 4 gras ww sbar ww sbar cov 4 yrs ley 2 yrs grain: tc/ha 51 yr 2 yrs ley 4 yrs grain: tc/ha 51yr gc/t grain rotations with cover crops: no trend grain rotations without cc: tc/ha 51yr grain root crops: ~ - 5. tc/ha 51 yr

17 Effect of crop residue management on long term soil C dynamics, Bad Lauchstädt experimental site ( ) original rotation (all straw exported) all straw residue remains minimum value for average straw residues in literature maximum value for average straw residues in literature gc/t incorporate all straw residue: incorporate 1.7 t C/ha 2 yrs (as straw) t C/ha 51 yr incorporate.7 t C/ha 2 yrs - 3.1tC/ha 51yr original rotation (all straw removed): tc/ha 51 yr Attention! See poster for more details: Joachim Post et al.

18 SWIM application for impact studies Climate change impact assessment (water, crop yield, water quality: N) (VK, FH) Land use change impact assessment (water, water quality: N & P) (VK, AH)

19 Climate change impact on groundwater recharge Reference period Average = 133 mm Scenario (v. 32) Average = 84 mm - 37 % Difference map (Scenario Reference) mm

20 Climate change impact on crop yield Winter wheat: Change in % Winter barley: Change in % Silage maize: Change in % -35% Average = - 13 % Average = - 9 % Average = + 9 %

21 Climate change impact on N losses with water from arable land Difference map (Scenario Reference) -4 kg N/ha/yr

22 Land use change impact on N losses from diffuse sources and accumulated N & P loads (Nuthe, Babelsberg) N [t] A1 A2 B1 B2 C1 C2.1 C2.2 C2.3 D1.1 D1.2 D1.3 E N [kg/ha*a] Differenz Szenario C2.3 zu A1 24 Szenario C Szenario A1 N [kg/ha*a] P [t] N [kg/ha*a] A1 A2 B1 B2 C1 C2.1 C2.2 C2.3 D1.1 D1.2 D1.3 E

23 Selected references on SWIM SWIM description & validation: Water Quality: Krysanova, F. Wechsung, J. Arnold, R. Srinivasan, J. Williams, 2. PIK Report Nr. 69 "SWIM (Soil and Water Integrated Model), User Manual", 239p. Hattermann, F., V. Krysanova, F. Wechsung & M. Wattenbach, 25. Runoff simulations on the macroscale with the ecohydrological model SWIM in the Elbe catchment - validation and uncertainty analysis. Hydrological Proceses, 19, Post, J., A. Habeck, F. Hattermann et al., 24. "Evaluation of water and nutrient dynamics in soil-crop systems using the eco-hydrological catchment model SWIM (Soil and Water Integrated Model)." Nutrient Cycling in Agroecosystems, (submitted). Habeck, A. V. Krysanova and F. Hattermann, 25. Integrated analysis of water quality in a lowland mesoscale basin. Advances in Geosciences (submitted). Krysanova, V. and U. Haberlandt, 22. Assessment of nitrogen leaching from arable land in large river basins. Part I: Simulation experiments using a processbased model. Ecological Modelling, 15, (3), Krysanova, V. and Becker, A., Integrated Modelling of Hydrological Processes and Nutrient Dynamics at the River Basins Scale, Hydrobiologia, 41, Groundwater dynamics: Hattermann, F., V.Krysanova, F. Wechsung, M. Wattenbach, 24. Integrating groundwater dynamics in regional hydrological modelling. Environmental Modelling and Software, 19, Sediments and Erosion: Carbon module: Riparian zone module: Krysanova, V., Williams, J., Buerger, G., Oesterle, H., 22. Linkage between hydrological processes and sediment transport at the river basin scale - a modelling study. In: W.Summer & D.E. Walling (eds.) Modelling erosion, sediment transport and sediment yield. Int. Hydr. Prog., IHP-VI, Technical Doc. in Hydrology, No. 6, UNESCO, Paris, p Post, J., V. Krysanova, F. Suchow, 24. Simulation of water and carbon fluxes in agro- and forest ecosystems at the regional scale. Complexity and Integrated Resources Management. Trans. of the 2nd Biennial Meeting of the Int. Env. Modelling and Software Society (iemss), Manno. Hattermann, F., V.Krysanova, A. Habeck, A. Bronstert, 25. Integrating wetlands and riparian zones in rive rbasin modelling. Ecological Modelling (in print) Climate and land use change: Hattermann, F.,V. Krysanova, J. Post, F.-W. Gerstengarbe, P.C. Werner, F. Wechsung, 25. Assessing uncertainty in water availability in a Central European river basin (Elbe) under climate change. Hydrological Sciences Journal (submitted). Krysanova, V., Hattermann, F., and Wechsung, F., 25. Implications of complexity and uncertainty for integrated modelling and impact assessment in river basins. Environmental Modelling and Software, (in print). Krysanova, V., Hattermann, F., and Habeck, A., 25. Expected changes in water resources availability and water quality with respect to climate change in the Elbe river basin (Germany), Nordic Hydrology, (in print). Krysanova, V. and F. Wechsung, 22. Impact of Climate Change and higher CO 2 on hydrological processes and crop productivity in the state of Brandenburg, Germany. In: M. Beniston (ed.) Advances in Global Change Research,, v. 1, Wechsung, F., Krysanova, V., Flechsig, M., Schaphoff, S., 2. May land use change reduce the water deficiency problem caused by reduced brown coal mining in the state of Brandenburg? Landscape and Urban Planning, 51 /2-4,