Wetland Applications for Remote Sensing
The topic I chose to research for this web page assignment was the utilization of Remote Sensing in researching
wetland applications that are not always easily accessible to research teams.
Practical Techniques of Remote Sensing of Wetlands
Due to the patchy and
spectrally impure nature of
freshwater wetlands Medium
resolution sensors like
Landsat TM, miss many of
the patchy wetlands and
produce too many mixed
pixels that cannot be relied
upon for much accuracy at
this spectral resolution. These
mixed pixels increase errors.
Due to the nature of
freshwater wetlands it is
necessary to utilize high
spatial resolution sensors. In
certain cases the use of
hyperspectral imagery may be
necessary.
Another key element in the
utilization of remote sensing
imagery is the use of a series
Goetz et al., Copyright © 2004.
of imagery from a set period of time.
This is the only cost effective way to
determine the effects of rising sea
levels, hurricanes as well as droughts
on wetlands. This application utilizes
the Normalized Difference Vegetation
Index in order to quantify plant
biomass within a selected area. The
idea of utilizing multiple sets of
imagery from different periods of time
is not strictly limited to wetland
applications and is a commonly
accepted practice among remote
sensing professionals for many
reasons.
The entire purpose of this journal was
show that remote sensing imagery is a
viable option for determining the
Bog, © 2012 Nicholas Tonelli.
health of the vegetation at higher resolutions than traditional sensors were designed for. The research team
determined that this is a viable and much more cost effective method of collecting data about wetlands due to
the high cost of employing field studies to collect the same data.
Sediment Deposition in the San Francisco Bay Estuary
The first article that deals with the mapping of the San Francisco Bay Estuary in order to determine sediment
dynamics, estimate the time required for vegetation to be established within wetlands, and identify potential
changes in management strategies. This estuary area is currently undergoing rehabilitation of its salt flats.
Remote sensing is currently being utilized to determine first a base set of imagery in order to determine the rate
of sediment accumulation, as well as in-situ sediment.
The study utilizes Landsat-5 Thematic Mapper as well as the Advanced Spaceborne Thermal Emission and
Reflectance Radiometer. In this case the satellite imagery is being utilized in unison with field discovery
techniques of in situ samples. The majority of the satellite imagery was specifically used to map suspended
sediment within the San Francisco Bay. Within this rehabilitation project researchers were able to determine
seasonal variations of the suspended sediment. Given all of the collected imagery and data researchers were
able to predict the deposition patterns and therefor create an accurate accumulation model.
From the accumulation model that was created a sensitivity analysis was then performed in order to determine
the effect of changing variables on marsh equilibrium accumulation.
This research, without the utilization of remote sensing would have either been hindered by slow field
collection methods or would have been unable to create a complete accumulation model for the San Francisco
Bay Estuary.
Assessment of Agricultural Overtake of Wetlands
Due to remote sensing techniques ability to cover large
areas, rapid technical improvements, and ability to
differentiate different wetland plant communities in order
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to assess wetland conservation techniques it is
widely accepted as a useful tool within the
discovery process.
Copyright © Unie van Waterschappen 2010-2011
Currently remote sensing does not have the resolution to differentiate between separate plants within a small
area, remote sensing does allow for differentiation of plant groups.
The main objectives of this specific study were determine representative plant communities, explore the
interrelationship between wetland plant composition and water pressures, and test the abilities of remote sensing
to be a viable tool for the accurate assessment of wetland condition.
From the study it was determined that irrigation affects the plant communities that exist within certain
watershed areas. This was due in no small part to the utilization of higher resolution airborne multispectral
sensors. This type of sensor has both a higher spatial and spectral resolution than that of the Landsat Systems. In
order to detect small wetlands patches these higher resolution systems had to be utilized.
In order for this particular study to be complete the higher resolution sensor was required. The pixel size was
two meters square. This resolution allowed for a supervised classification at a much finer detail than would have
been viable with one of the medium resolution sensors.
The results of this study determined that the higher the agricultural hydrological pressure, the more degradation
occurred to the protected wetlands within the Mediterranean. Without the utilization of remote sensing
technology obtaining the high resolution and high accuracy model would not be repeatable at any scale.
Wetland Change
Assessment Using
Remote Sensing
The final article
dealt with the
documentation of
invasive species. In
order to
successfully manage
wetlands
composition remote
sensing was used to
document the
replacement of
native vegetation
with invasive
species. This study
took place at the
Bear River
Migratory Bird
Refuge wetlands
located in northern
Utah. Highresolution airborne
multispectral
imagery of the
refuge was collected
between 1992 and
2010.
From the collected
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imagery vegetation was classified. The results from this classification showed that invasive species are quickly
replacing native species in areas that are immediately adjacent to water delivery canals.
Through the course of the study,
management techniques such as
adjusting water depth in order to
control salinity levels and aquatic
vegetation and burning of invasive
species were found to be fairly
effective at controlling the spread of
invasive species.
http://baby.indstate.edu/gerstt/wetlands.html; Copyright © 2010 Indiana State
University
The use of remote sensing in this
application allowed the team to observe
the changes in vegetation in the
eighteen year period after a large flood
event. Once again the remotely sensed
imagery is not a complete picture unto
itself. The imagery had to be used in
unison with management plans and
field observations in order to determine
the overall effectiveness of the
management techniques utilized by the
team.
The imagery collected of the refuge had
a one meter resolution. This resolution is on the higher end of the resolutions available today for a reasonable
price.
After the imagery was collected, 260 locations were visited in the field in order to verify the vegetation types
within the studied imagery. This field collection allowed the team to determine the spectral signatures of certain
vegetation types.
After collecting both the aerial imagery and the field data both a supervised and unsupervised classification
were used to estimate both the vegetation cover as well as approximate the spread of invasive species.
The 2010 imagery, when used in concert with the 1992 imagery allowed the team to run change detection, a
feature in ERDAS IMAGINE 10.0 software. This change detection is used to calculate the difference in
between pre and post event images.
Overall it was determined that post event there is a higher percentage of invasive species within the wetlands
area, though it is also important to state that the management techniques utilized by the team are aiding in
stunting the growth of the invasive populations.
This web page was created by Kyle J. Blunn with the aid of research articles collected from the Montana State
University Library Databases. All sources of information and visual aids are presented below.
Works Cited
Bog, © 2012 Nicholas Tonelli.
Goetz et al., Copyright © 2004.
http://baby.indstate.edu/gerstt/wetlands.html; Copyright © 2010 Indiana State University
http://www.euwma.org/index.php?france Copyright © Unie van Waterschappen 2010-2011
http://outlineglobal.com.au/products/multispectral-aerial-imagery/ Copyright © 2013 Outline Global
Michelle Elizabeth Newcomer, Amber Jean Michael Kuss, Tyler Ketron, Alex Remar, Vivek Choksi & J. W.
Skiles (2014) Estuarine sediment deposition during wetland restoration:A GIS and remote sensing modeling
approach, Geocarto International, 29:4, 451-467, DOI:
10.1080/10106049.2013.798356
J. Martínez-López, M.F. Carreño, J.A. Palazón-Ferrando, J. Martínez-Fernández, M.A. Esteve, Remote sensing
of plant communities as a tool for assessing the condition of semiarid Mediterranean saline wetlands in
agricultural catchments, International Journal of Applied Earth Observation and Geoinformation, Volume 26,
February 2014, Pages 193-204, ISSN 0303-2434, http://dx.doi.org/10.1016/j.jag.2013.07.005.
(http://www.sciencedirect.com/science/article/pii/S0303243413000858)
Keywords: Semiarid wetlands; Remote sensing; Irrigated agriculture; Plant communities; Watershed
hydrological condition; Airborne multispectral sensors
Klemas, Victor. 2011. "Remote Sensing of Wetlands: Case Studies Comparing Practical Techniques." Journal
Of Coastal Research 27, no. 3: 418-427. Academic Search Complete, EBSCOhost (accessed November 24,
2014).
Vanderlinder, Melina Santos, Christopher M. U. Neale, David E. Rosenberg, and Karin M. Kettenring. 2014.
"USE OF REMOTE SENSING TO ASSESS CHANGES IN WETLAND PLANT COMMUNITIES OVER AN
18-YEAR PERIOD: A CASE STUDY FROM THE BEAR RIVER MIGRATORY BIRD REFUGE, GREAT
SALT LAKE, UTAH." Western North American Naturalist 74, no. 1: 33-46. Academic Search Complete,
EBSCOhost (accessed November 24, 2014).
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