Mangrove & Sea Level Rise, Indonesia 2023-02-28
Mangrove ecosystems fill important functions on our planet. Some examples of this are capture and storage of CO2 (sequestration), shoreline stabilization (such as erosion control), coastal protection (such as alleviation of coastal storm energy), ecosystem services, and habitat for diverse biota, including nursery for many aquatic fish species and other animals.
Example of an Indonesian Mangrove habitat. Photo: Ron © Ronrad / CC-BY-SA-2.0.
However..
• For more than 50 years, as a result of coastal erosion and anthropogenic deforestation (by aquaculture and coastal agriculture), Mangrove have declined.
• Future sea level rise (SLR) awaits, that Mangrove wont be able to adapt to.
• Only 6.9% of the worlds mangroves are protected (IUCN I-IV).
This scenario make up the background for this work, consisting of a geospatial analysis with mangrove distribution data and estimated SLR-data by the year 2100 (NOAA, 2022).
Which areas of Mangrove will be at risk?
Mangrove distribution zones and species diversity along each region (Deltares, 2014; Michel, 2014).
Limiting Factors
To make the analysis feasible, limitations had to be set. For example, the area was restricted to countries that when flooded, may disturb a specific limnic fish species, of Indonesia. All limitations were:
• Area - maximum set at 4 million km2 to manage processing time and constricted to countries were Chromobotia macracanthus live inland.
• Sea Level Rise - set to 0,9 m that equal estimated SLR for the year 2100 (NOAA, 2022).
• Mangrove species richness - areas with high species richness.
Figure 3. A group of Chromobotia macracanthus, endemic to the limnic ecosystems of Borneo and Malaysia.
Data
After data collection, the data was prepared and analyzed in several steps and visualized. Below, a zoomed in example area displaying Mangrove distribution and the resulting pixels of each feature.
Figure 4. Zoomed-in part of an example area displaying the data used and the result of the analysis.
Process & Tools
• Data & metadata collection (ETOPO, NASA etc.)
• Extraction of SLR from bathymetric & land data
• Data conversion
• Kernel Density Estimation
• Symbology
• Symbology
Result
The resulting pixels was finally converted into points and visualized as a heat map: presented with the Kernel Density Estimation method, to display the most vulnerable Mangrove areas in a future sea level rise (of 0,9 m).
Projection: WGS84
Spalding M, Kainuma M, Collins L (2010) © World Atlas of Mangroves. A collaborative project of ITTO, ISME, FAO, UNEP-WCMC, UNESCO-MAB, UNU-INWEH and TNC. London (UK): Earthscan, London. 319 pp. URL: data.unep-wcmc.org/datasets/5. Accessed 2023-04-11.
NOAA National Centers for Environmental Information (2022) © ETOPO 2022 15 Arc-Second Global Relief Model. NOAA National Centers for Environmental Information. DOI: 10.25921/fd45-gt74. Accessed 2023-02-01
