Marsh Accretion with Sea Level Rise Steve Crooks, Matt Brennan, Justin Vandever, Jeremy Lowe, PWA...
-
Upload
magdalene-mcdowell -
Category
Documents
-
view
214 -
download
0
Transcript of Marsh Accretion with Sea Level Rise Steve Crooks, Matt Brennan, Justin Vandever, Jeremy Lowe, PWA...
Marsh Accretion with Sea Level Rise
Steve Crooks, Matt Brennan,Justin Vandever, Jeremy Lowe, PWA
John Callaway, USF
Diane Stralberg, PRBO
RSM Science WorkshopApril 14, 2010
Sensitivity of bird habitat to sea level rise
Long term habitat evolution and sustainability of restored habitats
Quantification of carbon sequestration with sea level rise
Marsh Elevation
Marsh elevation response to: initial bed elevation, suspended sediment concentration, organic material accumulation, rate of sea level rise, and subsidence and compaction
Marsh98
Based on mass balance calculations described by Krone (1987)
Accretion rate depends on: availability of suspended sediment depth and period of inundation
As marsh aggrades, frequency and duration of flooding decreases and accretion rate decreases.
Natural Marshplain Elevation in 2100(relative to rising tidal waters)
Dry density of carbon: 500 kg m3Initial marsh elevation: MHHW
Orr, Crooks and Williams 2003 Will Restored Tidal Marshes Be Sustainable?San Francisco Estuary and Watershed Science. Vol. 1, Issue 1 (2003), Article 5.
Vegetation die-back
Restored Marshplain Elevation in 2100(relative to rising tidal waters)
Dry density of carbon: 500 kg m3Initial marsh elevation: -0.5m MHHW
Orr, Crooks and Williams 2003 Will Restored Tidal Marshes Be Sustainable?San Francisco Estuary and Watershed Science. Vol. 1, Issue 1 (2003), Article 5.
Vegetation die-back
Model Revisions
Allows acceleration of rate of sea level rise NRC-I (0.5m rise) NRC-III (1.5m rise)
Organic matter added directly to bed elevation
ASA/GSFC/METI/ERSDAC/JAROS,
and U.S./Japan ASTER Science Team
March 3, 2000
Richardson Bay
Petaluma Estuary
San Pablo Bay
Approach
Bio-geomorphic units
Sediment supply Organic
accumulation Sea level rise 100 year time
frame
Model Runs
Initial Bed Elevation Colonization elevation (+1.3m MLLW) MHHW (+1.8m MLLW) Subtidal, minimal waves (-0.6m MLLW)
SSC 25, 50, 100, 150, 300 mg/l
Organic Matter 0, 1, 2, 3 mm/yr
Rate of Sea Level Rise NRC-I, NRC-III
Low sediment availabilityConverts to mudflat
SLR Scenario: NRC-IIISuspended Sediment Conc: 25 mg/LOrganic sedimentation rate: 1.0 mm/yr
Medium sediment availabilityTracks colonization elevation
SLR Scenario: NRC-IIISuspended Sediment Conc: 150 mg/LOrganic sedimentation rate: 1.0 mm/yr
High sediment availabilityKeeps pace with SLR
SLR Scenario: NRC-IIISuspended Sediment Conc: 300 mg/LOrganic sedimentation rate: 1.0 mm/yr
High initial elevation has larger net change in elevation as less frequently inundated and receives less sediment.
Higher organic accretion raises bed elevations and reduces inundation period and inorganic accretion rate.
25mg/l – unlikely to sustain marshes
50mg/l – sustain marshes only under most favorable conditions (high initial elevation and organic accumulation)
100-150mg/l – sustain marshes for particular combinations