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Wonders of Wetlands
COESSING Regional Maritime UniversityAugust 9, 2019
Wonders of Wetlands(& coastal ecosystems)
COESSING Regional Maritime UniversityAugust 9, 2019
Coastal Zone
Coastal Zone
Coastal Zone
Three main classifications
Wave dominated
Three main classifications
Tidally dominated
Wave dominated
Three main classifications
Tidally dominated River
dominated
Wave dominated
Three main classifications
Tidally dominated River
dominated
Wave dominated
Parameters and processes of interest
Wave-dominated Coasts
• Fetch = the distance over which wind blows on the sea surface, generating and propagating waves
Wave-dominated coasts
12
• Wave height (H) = distance from crest to trough
Wave-dominated coasts
13
• Wave height (H) = distance from crest to trough
Wave-dominated coasts
14
Wave height
• Significant wave height (HS) = average height of the largest 1/3 of waves
Wave-dominated coasts
15
Rayleigh Distribution:
NOAA
• Significant wave height (HS) = average height of the largest 1/3 of waves
Wave-dominated coasts
16
Rayleigh Distribution:
NOAA
Atlantic Ocean Æ HS is about 2 m
Tidally-dominated coasts
17
Tidally-dominated coasts
18NOS Tidal Datums pub
Tidally-dominated coasts
19NOS Tidal Datums pub
Tidally-dominated coasts
20
High in the tidal frame
NOS Tidal Datums pub
Tidally-dominated coasts
21
High in the tidal frame
Low in the tidal frame
NOS Tidal Datums pub
Vegetation is influenced by the tide range
Flemming, Siliciclastic Back-Barrier Tidal Flats
Size of the tide range: Macro-, Meso-, Microtidal
Vegetation is influenced by the tide range
Flemming, Siliciclastic Back-Barrier Tidal Flats
Size of the tide range: Macro-, Meso-, Microtidal
Vegetation and landform are influenced by the tide range
Adopted from Haslett, Coastal Systems
Microtidal Mesotidal Macrotidal
Salt marshes
Mudflats
Funnel Estuaries
Tidal Deltas
Barrier Islands
River Deltas
River-dominated coasts
25
River-dominated coasts
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Seybold et al. 2007
http://www.seddepseq.co.uk/depositional_env/deltas/deltas.htm
http://www.seddepseq.co.uk/depositional_env/deltas/deltas.htm
http://www.seddepseq.co.uk/depositional_env/deltas/deltas.htm
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Sweet et al. 2017
Causes of sea level change
Can deltas keep pace with sea-level rise?
42Giosan et al. 2014
Can deltas keep pace with sea-level rise?
43Giosan et al. 2014
no net emissions Æ sea-level rise = 0.3 m by 2100high emissions Æ sea-level rise = 2.5 m by 2100
(Sweet et al. 2017)
Mangroves around the world
Source: Giri, 2016
Ecosystem Services from salt marshes and mangroves
1. Habitat2. Carbon sequestration 3. Water treatment4. Wave attenuation/erosion control 5. Valuable goods 6. Flood reduction
1. Habitat2. Carbon sequestration 3. Water treatment4. Wave attenuation/erosion control 5. Valuable goods 6. Flood reduction
Ecosystem Services from salt marshes and mangroves
Carbon Sequestration
Mangroves among the most carbon-rich forests in the tropics
Donato et al 2011
Carbon Sequestration
“Blue Carbon” is carbon stored in wet environments (marshes, sea grass, mangroves)
Carbon Sequestration
“Blue Carbon” is carbon stored in wet environments (marshes, sea grass, mangroves)
Occurs via sedimentation and biomass burial
Sediment Capture
Suspended Sediment
Sediment Capture
SSC =Suspended SedimentConcentration
Sediment Capture
Sediment Capture
Sediment Capture
Sediment Capture
Sediment Capture
Accretion
Sediment Capture
Burial of Biomass
Burial of Biomass
Burial of Biomass
Anaerobic Decomposition
verrryyyyyyy sloooowwAnd can be smelly
Burial of Biomass
Burial of Biomass
Burial of Biomass
ErosionAccretion
ErosionAccretion
• Greater biomass• High SSC• Inundation time• Desiccation time
Case Study: Spatial Mapping of Carbon Stock
• Field Measurement
Diameter Tape
Lily Lisa YevugahKNUST
Classified Landsat Image
• Insert: images
Lily Lisa YevugahKNUST
Results on Carbon Map
Lily Lisa YevugahKNUST
Mangroves can keep pace with sea level rise
Mangroves can keep pace withsea level rise
Mangroves can keep pace with sea level rise
Mangroves can keep pace with sea level rise
Mangroves can keep pace with sea level rise
Important! Rate of sea level rise is increasing
Mangroves can keep pace with sea level rise
Ecosystem Services from salt marshes and mangroves
1. Habitat2. Carbon sequestration 3. Water treatment4. Wave attenuation/erosion control 5. Valuable goods 6. Flood reduction
Water Treatment
http://www.wetlands-initiative.org/nutrient-removal/
Water Treatment
Ecosystem Services from salt marshes and mangroves
1. Habitat2. Carbon sequestration 3. Water treatment4. Wave attenuation/erosion control 5. Valuable goods 6. Flood reduction
Case Study: Wave Attenuation
Loss of wave energy (Æcalculate from wave height)
Case Study: Wave Attenuation
Loss of wave energy (Æcalculate from wave height)
Case Study: Wave Attenuation
Loss of wave energy (Æcalculate from wave height)
Smaller Larger
H H
Case Study: Wave Attenuation
Why do we care?
Smaller Larger
H H
1. Storm Protection2. Geomorphology3. Modelling
Case Study: Wave Attenuation
How do we measure it?
Case Study: Wave Attenuation
How do we measure it?
High-Frequency Pressure Sensors
Case Study: Wave Attenuation
How do we measure it?
Time [sec]
Dept
h [m
]
Case Study: Wave Attenuation
How do we measure it?
Time [sec]
Dept
h [m
]
Case Study: Wave Attenuation
How do we measure it?
Time [sec]
Dept
h [m
]
Case Study: Wave Attenuation
How do we measure it?
Time [sec]
Dept
h [m
]
Case Study: Wave Attenuation
How do we measure it?
Time [sec]
Dept
h [m
]Case Study: Wave Attenuation
Measured the depth every 8 sec → 8 Hz
Case Study: Wave Attenuation
Compare the waves at each station
Wave Attenuation C D
Calm Turbulent Pinsky et al. 2013
Wave Attenuation C D
Function of the local conditions
Pinsky et al. 2013
Conservation > Restoration
Conservation > Restoration
• Less resilient to sea level rise•More prone to erosion • Less belowground biomass
Salt ponds
Salt ponds
Conservation > Restoration
Hardened Shorelines
Hardened Shorelines
1. Need to plan for sea level rise for our future generations2. Consider how coastal development changes the natural coastal processes
Main Takeaways
Thank you! Medaase!
