NatureCoast – project Dune formation
Status: afgerond
Personen: Kathelijne Wijnberg (UT), Michel Riksen (WUR)
Onderwerp: eolische morfodynamiek op mega-nourishments, veldmetingen, data analyse, Argus video, duinvorming
Website: NatureCoast - EcoShape
Resultaten:
OBSERVED AEOLIAN DEVELOPMENTS
The first morphologic developments due to wind-driven sand transport at the Sandmotor consisted of: i) partially infilling of the lake, and the lagoon, predominantly from S-SW direction at a fairly constant rate (still ongoing), ii) foredune development at the toe of the dune reinforcement (which was implemented prior to construction of the Sandmotor) at alongshore varying rates, iii) scattered, ephemeral embryo dune development in interaction with establishment of annual vegetation. At some locations new incipient foredune ridges started to develop and incipient hummocky dunes have recently started to developed away from the primary dune front. The latter being initiated by the spontaneous establishment of perennial vegetation tussocks.
DISCUSSION
The creation of an elevated artificial coastline with dredged seabed material has led to surface armoring which affects the total amount of wind-driven sand supply to the dunes .The location of the lake and lagoon, combined with directional properties of the wind climate, steer an alongshore varying aeolian sediment supply towards the dunes. Potentially, the incipient hummocky dunes may also become a sediment sink area and as such modulate sand supply to the foredunes. The locations of new dune formation away from the primary dune foot are strongly tied to establishment of vegetation which is linked to the design property ‘elevation’ as this influences frequency of flooding. Also prevailing management practice regarding beach raking, allowed beach traffic, and fencing off of areas with incipient dune formation influenced vegetation establishment.
CONCLUSIONS
A mega-nourishment like the Sandmotor provides both accommodation space and source material for aeolian dunes to develop. Their observed space-time varying development is related to sediment supply but also clearly tied to establishment dynamics of vegetation, both being tied to the nourishment topography. Vegetation establishment can also be affected by beach management regulations.
Locaties: Zandmotor
Selectie van publicaties:
- Luijendijk, Arjen, and A. P. E. van Oudenhoven. The Sand Motor: A nature-based response to climate change: findings and reflections of the Interdisciplinary Research Program NatureCoast. Delft University Publishers-TU Delft Library, 2019.
- Williams, I.A., K.M. Wijnberg, S.J.M.H. Hulscher(2018). Detection of aeolian transport in coastal images. Aeolian Research 35: 47-57, (doi.org/10.1016/j.aeolia.2018.09.003)
- Van der Weerd, A.J., K.M. Wijnberg (2016). Aeolian sediment flux derived from a natural sand trap. J. of Coastal Research, Special Issue 75: 338-342.
- Van der Weerd, L., Wijnberg, K. (2015). Aeolian activity on a peninsula-shaped mega nourishment.Proceedings Coastal Sediments 2015, 11-14 May 2015, San Diego, USA, 12p.
- K Wijnberg, J Limpens, C Nolet, M van Puijenbroek, M Riksen, I Williams, 2018. Mega-nourishments and aeolian developments: Lessons learned six years into the sandmotor pilot project Proceedings of the Coastal Engineering Conference 36 (2018)
- Pit, Iris R., Jasper Griffioen, and Martin J. Wassen. "Environmental geochemistry of a mega beach nourishment in the Netherlands: Monitoring freshening and oxidation processes." Applied Geochemistry 80 (2017): 72-89.
- C Nolet, MJPM Riksen, 2019, Accommodation space indicates dune development potential along an urbanized and frequently nourished coastline Earth Surface Dynamics 7 (1), 129-145
- C Nolet, M van Puijenbroek, J Suomalainen, J Limpens, M Riksen, 2018. UAV-imaging to model growth response of marram grass to sand burial: Implications for coastal dune development Aeolian Research 31, 50-61
- MEB van Puijenbroek, J Limpens, AV de Groot, MJPM Riksen, 2017. Embryo dune development drivers: beach morphology, growing season precipitation, and storms Earth Surface Processes and Landforms 42 (11), 1733-1744
