1. The document discusses the construction of hybrid dunes in Barcelona to mimic natural processes on urban dunes. Marram grass is a key dune constructor but has been decaying within 10 years, reducing dune habitat. 2. A project was undertaken to learn how to construct and manage urban dunes for cultural ecosystem services. Techniques developed include transforming marram grass plantings into efficient sand-trapping systems and mapping prevailing winds to assess erosion risk. 3. The concept of ecosystem services is proposed as an explicit management tool to develop a nature-based solution involving policy analysis, governance, and participated coastal engineering for coastal defense and climate change adaptation.

1. Constructed ecosystem services:
the case of hybrid dunes at
Barcelona

2. 1-Mimicking natural processes on
urban dunes

4. Last mobile dunes 1980

5. 1992 the first maritime promenade in Spain with dunes as core element of
the landscape treatment

6. Transformations due to urbanization & modification of coastal dynamics
1956
Anthropocene!
2015

7. 1990
2004
2007-16
Disruption of natural longshore sand transport processes

8. Increasing flood prone beach areas extending more than 3km

9. Marram grass decay after less than 10 years

10. Something worrying when is the most relevant dune constructor. We have not found any
photograph of dunes without marram grass

11. Literature describes competition processes and soil patogens
as most relevant factor

12. Probably mechanical sieving impedes the natural sand aeolian transport, but is only one of the relevant
factors

13. The accumulation of dog excreta can also be a problem for a plant which requires oligotrophic
soils

14. Without marram grass and aeolian sand transport, dune relief disappears.
No more bare sand and its biodiversity

15. Pine tree encroachment is another factor of dune habitat reduction

16. Altered ecosystem but biodiversity still remaining. Still on time to react!

17. An European project + the Metropolitan Administration of Barcelona
Goals:
1. Learn how to construct urban dunes
2. Learn how to manage the huge demand of cultural ecosystem services of the urban dunes.

18. Socio-cultural and economic processes
Cartographies of intensity of use along the year

19. Dune construction from beach sand

20. Wind is no more constructing dunes, but …

21. .. still keeps its ability to erode dunes and uproot marram grass

22. In just 8 weeks marram grass uprooted and invasive species stablished

23. Determination of prevailing constructing/eroding winds from historic flights
and fieldwork

24. Erosion risk can be mapped along dune structures.

25. We have developed a new system to transform marram grass plantings in to
efficient sand-trapping systems
Marram grass as natural capital (dune builder)
Marram grass as natural capital and core element of a nature
based solution

26. 2-Coastal dynamics & decision chain

27. No dunes, no beach!!
When beach width is not enough to provide a comfort strip

28. The only official way to protect the coastline is beach nourishment
(100,000m3/yr). No long-term strategy

29. Sand nourishment has not modified the emerged beach profile which
keeps vulnerable to flooding

30. Beach nourishment hasn’t stopped erosion processes

31. The need of a policy analysis

32. A decision environment which is not evidence-based

33. A highly hierarchical, authoritative and unchecked decision process

34. The most dependent stakeholders without capacity to intervene on
the decision-making process

36. Time to think on improving the governance environment

37. 3- Ecosystem services concept as an explicit
management tool

38. LIDAR and satellite images has become very precise

39. A retraslocation of only 6.000m3 of emerged sand has
proved to be much more efficient & effective

40. And a previous project done at Calafell (50km south)
beach will work at Castelldefels.

41. Efficient storm water retention basins
Beautiful landscapes
Biodiversity

42. There’s a big chance for a management plan of the
emerged sand budget, combining precise LIDAR
information, dune construction, beach profile
reconstruction and coastal lagoon excavation
A nature-based solution for
coastal defence and climate
change adaptation.

43. An evidence-based management plan that includes a
strong social component

44. We are modelling scenarios for RCP 2.6 (57cm SLR and 25 m of beach
regression, yr 2.100) for the different factors: wahsover risk, erosion, flood
events,...

45. But adapting fast to much more
near ones!
(this is Emilia Romagna on Italy
last year)

46. A nature-based solution to get resilient beaches

47. With reliable data from LIDAR yearly flights

48. http://maps.croma.org.es/geoserver/www/cr004_
visor-ampliat.html
With a Web Map service

49. Nature-based solution involving policy analysis, governance, and
participated coastal engineering
lascurain@sgm.es
@volemdunes
http://www.operas-project.eu/