Characterizing Tidal Inundation of Wetlands in the Murderkill ...
Characterizing Tidal Inundation of Wetlands in the Murderkill Estuary (Kent County, DE) Thermal Imaging
Tom McKenna Delaware Geological Survey University of Delaware
Can temperature p be used as an indicator of inundation?
LiDAR
Surface Elevation
January 14, 2009
Tidal Inundation
Supported by Kent County & Delaware DNREC
What causes low DO in the tidal Murderkill River? Issue: ssue low o DO O ((EPA “impaired pa ed waters”) ate s ) Question: appropriate TMDLs for nutrients? (EPA “pollution control strategy”)
river i / marsh h biogeochemical bi h i l interaction? i t ti ?
Webbs Marsh July 3, 2008 low tide
WWTP extensive salt marsh
Waste Water Treatment Plant? NJ
DE Bay
DE
Primary Research Question
What processes processes, sources sources, and sinks control low DO in the tidal Murderkill River?
Numerical Water-Quality Modeling site-specific site specific conceptual concept al models and input data p parameterizations of p processes that are difficult to model explicitly and/or require information not easily obtainable 9 9 9 9 9
tidal inundation of marshes biogeochemical cycling in marshes nutrient fluxes in/out marshes primary productivity sediment oxygen demand
De la ware Bay
McGinnis Pond
Andrews La ke
Course y Pond
M cColley Pond
WWTP
Tidal inundation of marshes The flow of water on salt marsh platforms is still poorly characterized. New conceptual models are being developed. developed
Challenges: 9 microtopography i t h 9 groundwater / surface-water interaction 9 anthropogenic alteration (since late 1600s) 9 inundation / vegetation relationship 9 very dynamic system 9 dense vegetation 9 overland flow in estuary estuary-scale scale models
upland marsh platform
secondary tidal channel
primary tidal channel
“Discrepancies p in tidal phase p and elevation in a numerical model can be accommodated by the modeling calibration process but can severely limit the explanatory power and predictive capabilities of the model.” (French, 2003)
Methods for determining inundation Hydrodynamic Model ((Overland Flow))
Tide Gages
Elevation Survey
Vegetation Survey
Comment
Model based on distribution of vegetation communities (indirect) No
Few
Yes
Yes
No
No
No
Yes
assumes correct conceptual model
Model based on tide and ground-surface elevation (direct) Yes
Many
ground-based
Yes
Yes/No
Many/Few
ground-based or LiDAR
Yes/No
No
Few
LiDAR
No
“Cadillac”
Temperature p
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Model for tidal inundation Preliminary model makes VERY simple (and wrong) assumption of Instantaneous inundation of entire marsh based on water elevation at Bowers Beach. Beach How wrong? Working towards more complex representation: 9 tidal propagation: function for instantaneous tide level for specified reaches of Murderkill River using data from tide gages at Frederica and Bowers Beach TLr = f(xr,t) 9 assign TLr to a subset of marshes along the reach 9marsh subset inundated based on TLr and set of spatial parameters representing (raster layers): • marsh elevation • attenuation/amplification of tidal amplitude • phase shift of tide based on distance from river/creek/ditch
Testing g model of tidal inundation Direct measurement: water level, temperature, and salinity in tidal creeks / ditches using g data loggers gg (time ( and instrument intensive). ) Marsh platform p instrumentation?
ALTERNATIVE: Can observations of environmental temperature be used to capture spatio-temporal spatio temporal dynamics of inundation (less expensive, more representative of spatial heterogeneity)?
Water W t flow fl and d heat h t transfer t f are highly-coupled processes.
7:19 DST
105
Temperature loggers on marsh platform
Environmental Thermography
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Establishing a common vertical datum low relief on marsh p platforms so minimizing g elevation error and bias is critical
asset
source
datum type
vertical datum
LiDAR monuments monuments
USGS DELDOT NGS
ellipsoidal ellipsoidal ellipsoidal
NAD83 NAD83 NAD83
monuments
NGS
orthometric
NAVD88
tide gages
USGS
orthometric
NGVD29
tide prediction
NOAA
tidal
MLLW
Geoid model: GEOID03
/ VDATUM software (NOAA) convert between ellipsoid, orthometric, and tidal datums
Conducted least squares adjusted GPS-RTK survey 8 reference monuments; minimally constrained
Survey corrections Elevation adjustments of up to 55 cm ! Significant g for accurate modeling g of marsh platform p inundation and hydrodynamics in river. Correction (m) reference elevation value
NGVD29 to NAVD88
least square adjust
Total
USGS Bowers gage
-0.34
-0.24
+0.03
-0.55
USGS Webbs gage
-0.34
-0.24
+0.03
-0.55
USGS Frederica gage
0.00
-0.24
+0.08
-0.16
N Bowers ref. monument
+0.03
+0.03
Barretts Ch. ref. monument
+0.08
+0.08
LiDAR ref. monument
+0.08
+0.08
Location
(m)
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
ELEVATION MAPPING LIDAR survey by b USGS / NASA Mark Nardi & Wayne Wright
2008; low spring tide; leaf-off
EAARL Experimental Advanced Airborne Ranging g g LiDAR
Digital Elevation Model LiDAR survey scale optimized for marsh topography
Murderkill M d kill River
salt marsh uplands LiDAR data collected for other purposes by b commercial i l LiDAR vendors is not optimal for mapping marsh topography.
Delaware y Bay
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Frederica Webbs Slough tidal datums shown for Bowers (VDatum)
Preliminary model makes VERY simple (and wrong) assumption of Instantaneous inundation based on water t elevation l ti att Bowers B Beach B h But how wrong?
MTL
MLW
MLLW
75th % MH HHW
Bowers
85% of time b l below MHW
MH HW
3 gages (USGS)
Fraction o of time watter level be elow given n elevation n
Cumulative Probability of Tide Being Below an Absolute Elevation
median
45% of time below MTL
25th % 2% % off time below MLW
-1.5
Elevation (m)
Digital Elevation Model LiDAR
Delaware Bay
Murderkill River
uplands
salt marsh
elevation < mean tide level -0.02 0 02 m NAVD88LSA
using tide levels from Bowers Beach gage
elevation < 0.4 m 0 4 m NAVD88LSA 0.4
using tide levels from Bowers Beach gage
elevation < mean high water 0 6 m NAVD88LSA 0.6
using tide levels from Bowers Beach gage
elevation < mean highest high water 0 75 m NAVD88LSA 0.75
using tide levels from Bowers Beach gage
elevation < 0.9 m 0 9 m NAVD88LSA (> MHHW) 0.9
using tide levels from Bowers Beach gage
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Data Loggers in Webbs Marsh ~ 1 year at 6-minute sampling interval temperature temperature, salinity, level temperature, salinity, level, velocity, pH, DO
Murderkill R R.
3 2
1
Murderkill R
WS
Likely Temperature Signals from Inundation? season
temperature air
spring summer fall winter
day warm warm cool cool
nite cool cool cool cold
water warm/cool warm warm/cool cool
Temperature signals of inundation at 3 sites on the marsh platform (over 7 days) inundation progresses through time from site 1 to site 3 Jun 1, 2008
Jun 8, 2008
night day oC
1
oC
2
oC
3
start of inundation at site 1
start of inundation at site 3
Water temperature @ Webbs Slough (WS) oC
air temp. p temperature difference (site 1 – site WS)
m
Webbs Slough (WS) tide
Phase lag of inundation relative to tide level at Webbs Slough area • secondary ditches • Spartina alterniflora near ditches • Spartina alterniflora away from ditches p p patens • Spartina
minutes 10-20 20-40 60-90 60-90
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
MULTI-SPECTRAL IMAGING
Reflected Energy
Emitted Energy Thermal Bands
UV Visible 0.4µm
NIR
SWIR
1.0µm
1.7µm
MWIR 3.0µm
LWIR 5.0µm
thi study this t d
8.0µm
14.0µm
Environmental Thermography (Thermal Imaging of the Environment) • measure “apparent” temperature of remote surfaces located centimeters to kilometers away • absolute temperature can be calculated 9 emissivity y of a material ((e.g. g water,, sediment,, vegetation) g ) 9 geometry of the observing system
• can be used 9 as a quick investigative tool 9 for detailed lab / field studies of dynamic processes • natural, natural engineered engineered, industrial
Imaging g g Platforms
Temperature Time Series of Tidal Mixing in Webbs Slough (May 15, 2008) 12
visual
lift platform
°C
18
Cooler water from the Murderkill River flows into Webbs Slough during flood tide and back out during ebb tide 5:49 DST
5:34 DST
0 min 6:34 DST
60
7:34 DST
120
flood tide
15
sunrise
6:49 DST
75 7:49 DST
135
6:04 DST
6:19 DST
30
45
7:04 DST
high tide
90
8:04 DST
150
7:19 DST
105 8:19 DST
165 min
ebb tide
Temperature Time Series Showing Inundation of Marsh Platform flood tide 8:44 PM EST
visual 12/13/2008
warmer water (gray blue) on colder (red) marsh surface
B
B A thermal imager location
816-817
A
high tide
9:04 PM EST
B
A 882-885
ebb tide
9:42 PM
B
July 31, 2008 early evening
A 1062-1064
Image of Marsh Platform Inundation warmer water flowing g onto cold marsh surface
Webbs Marsh December 13, 2008 high spring tide cold ld morning i (subfreezing) ( bf i ) helicopter platform
inundated platform is “warm” (orange)
A B B channels are “hot” (yellow)
A
Differentiating Sources of Water
Thermal Image cold water (black) ponded on marsh platform after recent rain event
Visual Image B B A
A
warm water (white) in Brockonbridge Gut Webbs Slough, Gut, Slough and ditches 12/13/2008 9:56 AM
high tide
Conclusions Salt-marsh S lt h elevations l ti in i upper Murderkill M d kill Estuary E t (Frederica) are lower than lower estuary (Bowers Beach)
Common vertical datum is critical for quantifying tidal inundation using in-situ instrumentation.
Environmental temperature can be used to capture spatio-temporal dynamics of inundation. – inexpensive in in-situ situ data loggers – environmental thermography
Tom McKenna Delaware Geological Survey University of Delaware
Can temperature p be used as an indicator of inundation?
LiDAR
Surface Elevation
January 14, 2009
Tidal Inundation
Supported by Kent County & Delaware DNREC
What causes low DO in the tidal Murderkill River? Issue: ssue low o DO O ((EPA “impaired pa ed waters”) ate s ) Question: appropriate TMDLs for nutrients? (EPA “pollution control strategy”)
river i / marsh h biogeochemical bi h i l interaction? i t ti ?
Webbs Marsh July 3, 2008 low tide
WWTP extensive salt marsh
Waste Water Treatment Plant? NJ
DE Bay
DE
Primary Research Question
What processes processes, sources sources, and sinks control low DO in the tidal Murderkill River?
Numerical Water-Quality Modeling site-specific site specific conceptual concept al models and input data p parameterizations of p processes that are difficult to model explicitly and/or require information not easily obtainable 9 9 9 9 9
tidal inundation of marshes biogeochemical cycling in marshes nutrient fluxes in/out marshes primary productivity sediment oxygen demand
De la ware Bay
McGinnis Pond
Andrews La ke
Course y Pond
M cColley Pond
WWTP
Tidal inundation of marshes The flow of water on salt marsh platforms is still poorly characterized. New conceptual models are being developed. developed
Challenges: 9 microtopography i t h 9 groundwater / surface-water interaction 9 anthropogenic alteration (since late 1600s) 9 inundation / vegetation relationship 9 very dynamic system 9 dense vegetation 9 overland flow in estuary estuary-scale scale models
upland marsh platform
secondary tidal channel
primary tidal channel
“Discrepancies p in tidal phase p and elevation in a numerical model can be accommodated by the modeling calibration process but can severely limit the explanatory power and predictive capabilities of the model.” (French, 2003)
Methods for determining inundation Hydrodynamic Model ((Overland Flow))
Tide Gages
Elevation Survey
Vegetation Survey
Comment
Model based on distribution of vegetation communities (indirect) No
Few
Yes
Yes
No
No
No
Yes
assumes correct conceptual model
Model based on tide and ground-surface elevation (direct) Yes
Many
ground-based
Yes
Yes/No
Many/Few
ground-based or LiDAR
Yes/No
No
Few
LiDAR
No
“Cadillac”
Temperature p
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Model for tidal inundation Preliminary model makes VERY simple (and wrong) assumption of Instantaneous inundation of entire marsh based on water elevation at Bowers Beach. Beach How wrong? Working towards more complex representation: 9 tidal propagation: function for instantaneous tide level for specified reaches of Murderkill River using data from tide gages at Frederica and Bowers Beach TLr = f(xr,t) 9 assign TLr to a subset of marshes along the reach 9marsh subset inundated based on TLr and set of spatial parameters representing (raster layers): • marsh elevation • attenuation/amplification of tidal amplitude • phase shift of tide based on distance from river/creek/ditch
Testing g model of tidal inundation Direct measurement: water level, temperature, and salinity in tidal creeks / ditches using g data loggers gg (time ( and instrument intensive). ) Marsh platform p instrumentation?
ALTERNATIVE: Can observations of environmental temperature be used to capture spatio-temporal spatio temporal dynamics of inundation (less expensive, more representative of spatial heterogeneity)?
Water W t flow fl and d heat h t transfer t f are highly-coupled processes.
7:19 DST
105
Temperature loggers on marsh platform
Environmental Thermography
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Establishing a common vertical datum low relief on marsh p platforms so minimizing g elevation error and bias is critical
asset
source
datum type
vertical datum
LiDAR monuments monuments
USGS DELDOT NGS
ellipsoidal ellipsoidal ellipsoidal
NAD83 NAD83 NAD83
monuments
NGS
orthometric
NAVD88
tide gages
USGS
orthometric
NGVD29
tide prediction
NOAA
tidal
MLLW
Geoid model: GEOID03
/ VDATUM software (NOAA) convert between ellipsoid, orthometric, and tidal datums
Conducted least squares adjusted GPS-RTK survey 8 reference monuments; minimally constrained
Survey corrections Elevation adjustments of up to 55 cm ! Significant g for accurate modeling g of marsh platform p inundation and hydrodynamics in river. Correction (m) reference elevation value
NGVD29 to NAVD88
least square adjust
Total
USGS Bowers gage
-0.34
-0.24
+0.03
-0.55
USGS Webbs gage
-0.34
-0.24
+0.03
-0.55
USGS Frederica gage
0.00
-0.24
+0.08
-0.16
N Bowers ref. monument
+0.03
+0.03
Barretts Ch. ref. monument
+0.08
+0.08
LiDAR ref. monument
+0.08
+0.08
Location
(m)
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
ELEVATION MAPPING LIDAR survey by b USGS / NASA Mark Nardi & Wayne Wright
2008; low spring tide; leaf-off
EAARL Experimental Advanced Airborne Ranging g g LiDAR
Digital Elevation Model LiDAR survey scale optimized for marsh topography
Murderkill M d kill River
salt marsh uplands LiDAR data collected for other purposes by b commercial i l LiDAR vendors is not optimal for mapping marsh topography.
Delaware y Bay
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Frederica Webbs Slough tidal datums shown for Bowers (VDatum)
Preliminary model makes VERY simple (and wrong) assumption of Instantaneous inundation based on water t elevation l ti att Bowers B Beach B h But how wrong?
MTL
MLW
MLLW
75th % MH HHW
Bowers
85% of time b l below MHW
MH HW
3 gages (USGS)
Fraction o of time watter level be elow given n elevation n
Cumulative Probability of Tide Being Below an Absolute Elevation
median
45% of time below MTL
25th % 2% % off time below MLW
-1.5
Elevation (m)
Digital Elevation Model LiDAR
Delaware Bay
Murderkill River
uplands
salt marsh
elevation < mean tide level -0.02 0 02 m NAVD88LSA
using tide levels from Bowers Beach gage
elevation < 0.4 m 0 4 m NAVD88LSA 0.4
using tide levels from Bowers Beach gage
elevation < mean high water 0 6 m NAVD88LSA 0.6
using tide levels from Bowers Beach gage
elevation < mean highest high water 0 75 m NAVD88LSA 0.75
using tide levels from Bowers Beach gage
elevation < 0.9 m 0 9 m NAVD88LSA (> MHHW) 0.9
using tide levels from Bowers Beach gage
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
Data Loggers in Webbs Marsh ~ 1 year at 6-minute sampling interval temperature temperature, salinity, level temperature, salinity, level, velocity, pH, DO
Murderkill R R.
3 2
1
Murderkill R
WS
Likely Temperature Signals from Inundation? season
temperature air
spring summer fall winter
day warm warm cool cool
nite cool cool cool cold
water warm/cool warm warm/cool cool
Temperature signals of inundation at 3 sites on the marsh platform (over 7 days) inundation progresses through time from site 1 to site 3 Jun 1, 2008
Jun 8, 2008
night day oC
1
oC
2
oC
3
start of inundation at site 1
start of inundation at site 3
Water temperature @ Webbs Slough (WS) oC
air temp. p temperature difference (site 1 – site WS)
m
Webbs Slough (WS) tide
Phase lag of inundation relative to tide level at Webbs Slough area • secondary ditches • Spartina alterniflora near ditches • Spartina alterniflora away from ditches p p patens • Spartina
minutes 10-20 20-40 60-90 60-90
common x,y,z datum “apples to apples”
elevation marsh surface (LiDAR)
Components p of Inundation Study
very low relief minimize error and remove bias
instrument locations (e.g. tide level)
preliminary inundation model highly parameterized
d t loggers data l water level, temperature, and salinity time-series to document inundation and develop & test models
air temperature & pressure, solar radiation temperature on marsh platform (air/water) Can we use temperature as an indicator of inundation?
thermal imaging Can we use temperature as an indicator of inundation?
MULTI-SPECTRAL IMAGING
Reflected Energy
Emitted Energy Thermal Bands
UV Visible 0.4µm
NIR
SWIR
1.0µm
1.7µm
MWIR 3.0µm
LWIR 5.0µm
thi study this t d
8.0µm
14.0µm
Environmental Thermography (Thermal Imaging of the Environment) • measure “apparent” temperature of remote surfaces located centimeters to kilometers away • absolute temperature can be calculated 9 emissivity y of a material ((e.g. g water,, sediment,, vegetation) g ) 9 geometry of the observing system
• can be used 9 as a quick investigative tool 9 for detailed lab / field studies of dynamic processes • natural, natural engineered engineered, industrial
Imaging g g Platforms
Temperature Time Series of Tidal Mixing in Webbs Slough (May 15, 2008) 12
visual
lift platform
°C
18
Cooler water from the Murderkill River flows into Webbs Slough during flood tide and back out during ebb tide 5:49 DST
5:34 DST
0 min 6:34 DST
60
7:34 DST
120
flood tide
15
sunrise
6:49 DST
75 7:49 DST
135
6:04 DST
6:19 DST
30
45
7:04 DST
high tide
90
8:04 DST
150
7:19 DST
105 8:19 DST
165 min
ebb tide
Temperature Time Series Showing Inundation of Marsh Platform flood tide 8:44 PM EST
visual 12/13/2008
warmer water (gray blue) on colder (red) marsh surface
B
B A thermal imager location
816-817
A
high tide
9:04 PM EST
B
A 882-885
ebb tide
9:42 PM
B
July 31, 2008 early evening
A 1062-1064
Image of Marsh Platform Inundation warmer water flowing g onto cold marsh surface
Webbs Marsh December 13, 2008 high spring tide cold ld morning i (subfreezing) ( bf i ) helicopter platform
inundated platform is “warm” (orange)
A B B channels are “hot” (yellow)
A
Differentiating Sources of Water
Thermal Image cold water (black) ponded on marsh platform after recent rain event
Visual Image B B A
A
warm water (white) in Brockonbridge Gut Webbs Slough, Gut, Slough and ditches 12/13/2008 9:56 AM
high tide
Conclusions Salt-marsh S lt h elevations l ti in i upper Murderkill M d kill Estuary E t (Frederica) are lower than lower estuary (Bowers Beach)
Common vertical datum is critical for quantifying tidal inundation using in-situ instrumentation.
Environmental temperature can be used to capture spatio-temporal dynamics of inundation. – inexpensive in in-situ situ data loggers – environmental thermography
