Hydrological Modelling of Small Scale Processes in a Wetland Habitat

1. Hydrological Modelling of Small Scale Processes in a Wetland Habitat O. M. JOhansen, j.b. jensen & m.l. pedersen Aalborg University, Department of Civil Engineering - Water and Soil

2. Objective of this study: • To simulate the detailed flow paths in Danish river valley containing protected rich fens and natural springs. • Understanding and quantifying the hydrological processes is an important step towards predicting the ecological responses in these habitats • Relevance: • A planned well field close to the habitat area initiated the investigations • Focus in presentation: • The process of gaining knowledge on the hydrological system PhD student Ole Munch Johansen

3. Location of the Lindenborg River system

4. Hydro-geologicalsettings

5. Methods • Data collection programme

6. Methods 0.8 km2 Legend Observation well Spring Regional model Rich fen Detailed model 235 km2 • Data collection programme • Combining local and regional distributed hydrological models

7. Methods • Data collection programme • Combining local and regional distributed groundwater models • Using models and field measurements for hypothesis testing

8. Methods

9. Spring Supply for fish farm Rich Fen

10. Main results from stationary model simulations Limestone aquifer River spring Rich fen

11. Water level measurements

12. Main results from stationary model simulations • Flow through rich fen: 1.2 mm/day as average surface runoff -The flow is controlled by the vertical pressure gradient • 80 % of the discharge to the river comes from natural springs (and does not flow through the rich fens or the river valley deposits)

13. Recent and future work

14. Thank you!