Presentation by Chris van Diemen, University of Amsterdam (UvA), Netherlands, at the Delft3D - User Days (Day 1: Hydrodynamics), during Delft Software Days - Edition 2017. Monday, 30 October 2017, Delft.

1. Chris van Diemen
chris.vandiemen@student.uva.nl

2. Moth Plant Dispersion Modelling
Influences of synoptic weather patterns on Island connectivity
MSc Thesis by: Chris van Diemen
chris.vandiemen@student.uva.nl
Coordinators: Kenneth Rijsdijk & Gerard Oostermeijer
Little and Great Barrier island in the Hauraki Gulf with model grid overlay (source: ESRI)

3. Content
● Introduction
● Methods
● Results
● Discussion
● Conclusion
● Questions
Introduction - Research questions - Methods - Results - Discussion- Conclusion

4. (van Kleunen et al., 2015)

6. http://www.nationalpedia.com

7. Introduction - Research questions - Methods - Anticipated results - Limitations - Conclusion
Source: wired.com

8. December 2015
(Photograph: Google street view)
February 2016
(Photograph by Graham Dyche)
Pukekohe
Introduction - Research questions - Methods - Results - Discussion- Conclusion

9. Introduction - Research questions - Methods - Results - Discussion- Conclusion

10. (Photograph by Graham Dyche)

11. Research questions
Main research question:
● What are the most likely source and sink locations for moth plant
invasion of the Barrier Islands now and in the future?
Sub questions:
● What are the locations that are likely to harbour and promote the
moth plant?
● How can a numerical model account for the routes of seed dispersal
in the Hauraki Gulf?
● At which rates can the moth plant exploit specific routes to disperse
over the Hauraki Gulf by air and water current?
● Can the correlations between synoptic weather types and local
dispersal patterns be used to predict dispersal in the future?
Introduction - Research questions - Methods - Results - Discussion- Conclusion

12. Methods

13. Methods
rch is on weather conditions for explaining dispersal routes.
Fig 4 Hypothetical linked source and sink pair
Introduction - Research questions - Methods - Results - Discussion- Conclusion
Delft 3D

15. Hydrodynamic modelling
https://earth.nullschool.net
- Input data
- Tidal constituents
- Sensitivity testing

16. Input data
Data name Variables Spatiotemporal scale
ECMWF
ERA-40
&
ERA-interim
- Air current
- Air temperature
- Water surface
temperature
1975 - 2015
6 hour time steps
0.75 degree
resolution
LINZ
Water levels
- Water levels 1 minute and hourly
time steps
3 locations
NIWA
Bathymetry
- Bathymetry 20*20 m resolution
Salinity - Salinity Averaged value over
entire gulf area
(Black et al., 2000; Uppala et al., 2005; NIWA, 2016; LINZ. 2017; UHSLC. 2017; Dee et al., 2011)

17. Tidal constituents
- T-tide toolbox
- 1 water level location as input
- 2 water level locations for sensitivity analysis
(Pawlowicz, Beardsley, and Lentz, 2002)

18. Sensitivity testing
- Time steps
- Layers
- Wind forcing
Best configuration:
2 minute time steps,
1 dimensional, and
wind forcing applied.

19. Particle tracking
Animation
Introduction - Research questions - Methods - Results - Discussion- Conclusion

23. Source Sink

24. Discussion

25. Temporal and Synoptic Weather Patterns

26. Discussion
- no landing conditions included in the model
- No connection found between large scale synoptic weather
patterns
- Simplified model needed for use by governments
- Future research might focus on more local patterns (K2K)

27. (Kidson, 2000; Jiang, 2011)

28. Conclusion and Suggestions
Main question:
- Risk maps and identified routes indicate the most likely
routes to be taken by the moth plant
Sub questions
- HSM shows most likely locations for month plant to thrive
- Delft3D model and wind data used for dispersal modelling
- Rates revealed by counting particles that end up in zones
- K2K types might enable a model with predictive power in
the future.

29. Source: coolnaturephotos.com
Questions?
chris.vandiemen@student.uva.nl
chris.j.van.diemen@gmail.com

30. References
Black, K. P., Bell, R. G., Oldman, J. W., Carter, G. S., & Hume, T. M. (2000). Features of 3‐dimensional barotropic and
baroclinic circulation in the Hauraki Gulf, New Zealand. New Zealand Journal of Marine and Freshwater Research,34(1), 1-28
Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P., Kobayashi, S., & Bechtold, P. (2011). The ERA‐Interim
reanalysis: Configuration and performance of the data assimilation system. Quarterly Journal of the royal meteorological society,
137(656), 553-597.
Jiang, N. (2011). A new objective procedure for classifying New Zealand synoptic weather types during 1958–2008.
International Journal of Climatology, 31(6), 863-879.
Kidson, J. W. (2000). An analysis of New Zealand synoptic types and their use in defining weather regimes. International
journal of climatology, 20(3), 299-316.
LINZ. (2017). Land Information New Zealand (LINZ). Retrieved 10 July 2017, from
http://www.linz.govt.nz/sea/tides/sea-level-data/sea-level-data-downloads
NIWA. (2016). NIWA Download Bathymetry Data. Retrieved 5 September 2016, from https://www.niwa.co.nz/our-
science/waters/bathymetry/download-the-data
Van Kleunen, M., Dawson, W., Essl, F., Pergl, J., Winter, M., Weber, E., ... & Antonova, L. A. (2015). Global exchange and accumulation of
non-native plants. Nature, 525(7567), 100-103.
UHSLC. (2017). University of Hawaii, Sea level center. Retrieved 11 July 2017, from http://uhslc.soest.hawaii.edu/data/?rq
Uppala, S. M., Kållberg, P. W., Simmons, A. J., Andrae, U., Bechtold, V. D., Fiorino, M., & Li, X. (2005). The ERA‐40
re‐analysis. Quarterly Journal of the Royal Meteorological Society, 131(612), 2961-3012.