Climate Change and Physical Development Threats, Challenges and Adaptation Responses in Coastal Communities: Grand Riviere, Trinidad

Transcription

1 Climate Change and Physical Development Threats, Challenges and Adaptation Responses in Coastal Communities: Grand Riviere, Trinidad Michelle Mycoo Ph.D. and Michael Sutherland Ph.D. Geomatics Engineering and Land Management, The University of the West Indies, St. Augustine, Trinidad

2 Leatherback Turtles Leatherback turtles are endangered species and climate change and SLR place further stress on their nesting sites. The loss of this endangered species would be significant in the context of community-based biodiversity protection and tourism-based sustainable livelihoods

3 SEA LEVEL RISE PROJECTIONS IPCC Category Projection Stated 1 0.4m 1.4m m 1.7m m 1.9m m 2.4m m 2.9m m 3.7m

4 SEA LEVEL RISE MODEL: DATA Collected Data Ground Control Points Contour data Topographic Data Arial Photograph (2007 with Colour) Spot heights along the beach Mean Sea Level Purpose To establish a reference control within the community, since existing controls were destroyed To get an accurate model of sea level rise and for the generation of 3D model To show what would be affected by the rise in sea level (Buildings, Property Boundaries, Roads, River etc.) To provide realistic visualization To get a detailed contour shape of the beach To establish a vertical reference control within the community

5 SEA LEVEL RISE MODEL: VISUALIZATION Simulated MSL at Grande Riviere Beach

6 SEA LEVEL RISE MODEL: VISUALIZATION Simulated 0.4m above MSL at Grande Riviere Beach

7 SEA LEVEL RISE MODEL: VISUALIZATION Simulated 0.6m above MSL at Grande Riviere Beach

8 SEA LEVEL RISE MODEL: VISUALIZATION Simulated 0.8m above MSL at Grande Riviere Beach

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10 Results The results show that between 44% and 68% of the beach area may disappear based on simulations in sea level rise. Informed by these projected scenarios, the community of Grande Riviere can gain some understanding of possible beach loss and coastal inundation due to sea level rise, and its potential impact upon sea turtle nesting sites.

11 Main Findings on Coastal Adaptation These existing buildings cannot be setback, but all new built development should be informed by setback distances. Several of these options exist as adaptation measures, but must be carefully selected in accordance with the characteristics of Grande Riviere Bay and understanding of coastal dynamics.

12 Guest house on the beach front

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14 Hard Engineering Measures The construction of seawalls, rock revetments, riprap, sandbag installations, groynes and jetties may be used in an attempt to adapt to climate change (Burke et al., 2004). Impediments: Beach armoring leads to accelerated erosion, which can hamper female turtles from accessing suitable nesting sites. In Barbados, seawalls have contributed to a decline in turtle nests (Choi et al., 2009). Expensive to construct and maintain. Only used as a last resort. Only used if the beach erosion is severe and needs immediate remedial action. Aesthetically unpleasing.

15 Revetment

16 Headland Control and Groynes

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18 Seawall and Boardwalk, Barbados

19 Soft Engineering Measures Setbacks (reduces light pollution) Beach nourishment Ecosystem-based measures Light pollution using site planning and green architecture Manual nest relocation Integrated Coastal Zone Planning and Management Environmental Impact Assessments

20 Coastal Setbacks Buffer area that can accommodate the naturally dynamic nature of beaches (French, 2006). Ensures preservation of sufficient beach habitat for turtle nesting and beach area for tourism-related recreation. Enhances the probability that artificial lighting will not shine directly on the beach (Belle and Bramwell, 2005) and affect turtle nesting. Setbacks cannot be implemented overnight.

21 Beach Restoration (or renourishment) If restoration is unavoidable, replacement sand should be similar (grain size, organic content) to that which was eroded to maintain, the suitability of the beach for the incubation of sea turtle eggs. Restoration should never occur during nesting and hatching seasons when heavy equipment and activity can deter nesting, crush eggs, and/or prevent hatchlings from successfully digging out of the nest. Steinitz et al. (1998) and Rumbold et al. (2001) have published data demonstrating that the number of nests decreases and the number of false crawls (unsuccessful nesting attempts) increases immediately following the renourishment of a beach. Crain et al. (1995) concluded that while beach restoration projects may enhance some nesting areas, in general the effects for sea turtles are negative.

22 Ecosystem based adaptation Re-vegetating beaches. Relatively cheap measure. Benefits range from cooling beaches through shading, reducing beach erosion by stabilising sediment to mitigation of greenhouse gases by acting as a carbon sink. Tree planting is an ideal activity to adapt in coastal areas as it can easily be made into a community activity, involving all ages, the results of which are obvious and tangible. The shade of trees along the beach has been shown to reduce the incubation temperature in exposed beach areas by 2 to 3 degrees centigrade.

23 Light pollution & Green Architecture Lighting onshore can discourage egg-bearing females from coming ashore to nest. A variety of effective management solutions to alleviate this problem: Light inspections to determine the lights which caused the highest amount of light pollution are required. Reduce light wattage. Shield light sources using appropriate designs. Recess luminaries into roof soffits. The use of lower pole-mounted luminaries Install timers and motion detectors and alternative long-wavelength light sources. Greening measures include ecological alternatives such as the use of native vegetation as light screens and the enhancement of dune profiles.

24 Integrated Coastal Zone Management ICZM recognizes the importance of the beach and landward areas and potential impacts on nesting sites. Seeks to engage stakeholders in consensus-building and adaptation.

25 Environmental Impact Assessments Evaluate all new coastal development projects and therefore have an opportunity to recommend that measures be adopted, which ensure the protection of turtle nesting and foraging sites.

26 GIS and Capacity Building GIS is a powerful communication tool. Engages communities and enhances the adaptation capacity of coastal communities to climate change, sea level rise, beach erosion and flooding. GIS has the capacity to produce visualizations and spatial analytical outputs that assist communities in learning about their environments. This new knowledge can empower communities to make appropriate decisions to safeguard their socioeconomic futures.

27 Final Conclusion The climate change adaptation measures discussed in this paper involve: A mix of institutional and behavioural responses, The use of technologies, and the design of climate resilient infrastructure. The extent to which these measures can be adopted and implemented depends on the adaptive capacity of the country and community, which is influenced not only by the level of economic development and access to technology, but also by social factors such as human capital and governance structures.

28 Future Steps Economic valuation of the beach and turtle nesting sites. Determine feasible adaptation options, using socialcost benefit analysis, so as to determine which are appropriate for the local communities to build their adaptive capacity for climate change and sea level rise.