Coastal protection value

The Challenge:
How important is the unique Bonairean coral reef for the protection of its habitants during stomrs and hurricanes? How does one value the worth of this protection?


The Approach:
A spatial coastal protection valuation model has been designed for Bonaire based on GIS analysis and available data. The coral data are derived from a spatial qualitative assessment by IMARES (2011). This coral dataset was as input for spatial information on coral cover and complexity. The dataset provides qualitative point information per 500 meter transect on the west coast of Bonaire.

  • Bathymetry point data provided by the Netherlands Hydrological Service was interpolated and used to measure the average depth in the reef zones.
  • A digital elevation model was created for the analysis, by interpolating a point elevation map, provided by IMARES.
  • An AutoCAD file with spatial planning information was geo-referenced and from this dataset, the parcel layer was selected for the analysis.
  • A database house prices of about 120 cases in the period 2006-2011. Local real estate agent based on Bonaire provided this dataset.
  • To calculate the wave energy dissipation an excel-based wave model (Sheppard et al., 2005) was applied2.
  • Also in the analysis: a poly line file of Bonaire’s coastline.

Bonaire_hurricane

Results & Recommendations:
The coastal protection value (CPV) of coral reefs is one of the ecosystem services that contribute to the economic value of coral reefs. The basic principle of coastal protection by coral reefs is the observation that reefs dissipate wave energy either by wave breaking or friction by reef structures. In this study, the coastal protection value (CPV) is estimated on 30 * 30 m grid cell level, which gives a more spatially explicit estimation of the CPV of coral reefs. The annual coastal protection values of the coral reefs of Bonaire for short-term (i.e. within 10 years) and long-term processes (i.e. beyond 10 years) are estimated at $33,000 and $70,000, respectively, based on private property. Adding public infrastructure the value of the coastal protection by the coral reefs will be way over 0.1 million USD.

Downloadable outputs: