analysis of shoreline change in connecticut · 7/19/2014 · change in connecticut 100+ years of...
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By: Kevin O’Brien (DEEP), Joel Stocker (UCONN-CLEAR), Juliana Barrett (CT Sea Grant) and Bruce Hyde (UCONN-CLEAR)
Analysis of Shoreline Change in Connecticut
100+ Years of Erosion and Accretion: Methodology and Summary Results
A cooperative effort between the Connecticut Department of Energy & Environmental Protection (DEEP), the Connecticut Sea Grant (CT Sea Grant) and the University of Connecticut Center for Land Use
Education and Research (UCONN-CLEAR)
7/19/2014
July 2014 Page 2 of 29
Contents Figures: .......................................................................................................................................................... 3
Tables: ........................................................................................................................................................... 3
Project Goal:.................................................................................................................................................. 4
Disclaimers & Caveats: .................................................................................................................................. 4
Summary: ...................................................................................................................................................... 4
Long-term rates (ca. 1880s - 2006) ........................................................................................................... 5
Short-term rates (1983 – 2006) ................................................................................................................ 5
Data Compilation: ......................................................................................................................................... 6
General Shoreline Archive ........................................................................................................................ 8
Uncertainty Estimates ............................................................................................................................... 9
Shoreline Change Analysis Data .............................................................................................................. 10
Data Review/Assessment ............................................................................................................................ 10
Data Processing: .......................................................................................................................................... 13
Overview ................................................................................................................................................. 13
Baseline Development ............................................................................................................................ 14
Transect & Statistical Generation ........................................................................................................... 16
Statistical Review and Processing: .............................................................................................................. 21
Short-Term Data (1983 – 2006) .............................................................................................................. 21
Long-Term Data (ca. 1880 – 2006) .......................................................................................................... 23
Works Cited ................................................................................................................................................. 27
Appendices: ................................................................................................................................................. 29
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Figures: Figure 1: Coastal USGS Quads by Year .......................................................................................................... 8
Figure 2: Sample shoreline data ................................................................................................................... 9
Figure 3: Examples of suitable (top) and unsuitable (bottom) shoreline vectors. ..................................... 12
Figure 4: Connecticut Shoreline Districts .................................................................................................... 18
Figure 5: Final Data Structure output ......................................................................................................... 19
Figure 6: Example of baselines, shoreline vectors, and analysis transects ................................................. 20
Figure 7: Example of shoreline transects clipped to the shoreline change envelope ................................ 20
Tables: Table 1: Uncertainty Terms ......................................................................................................................... 10
Table 2: Table of Short-term (1983 – 2006) statistics summary ................................................................. 23
Table 3: Table of Long-term (ca 1880 – 2006) statistics summary ............................................................. 26
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Project Goal: To conduct a Geographic Information System (GIS) time series analysis using maps of the Connecticut
shoreline from several different time periods between 1880 and 2006 (100+ years) so as to provide a
high-level, quantifiable data set describing CT shoreline trends from both a statewide, regional, and a
localized perspective.
Disclaimers & Caveats: Shoreline change data presented here may differ from those found in other sources; any differences do
not necessarily indicate other data sources are inaccurate.
When considering other sources of shoreline change, discrepancies are to be expected considering the
many possible ways of determining shoreline positions and rates of change, and the inherent
uncertainty in calculating these rates.
The results from this analysis represent shoreline movement under past conditions and are not intended
for use in predicting future shoreline positions or future rates of shoreline change.
The materials presented can be reasonably used to:
identify areas that have historically exhibited erosion or accretion trends;
identify areas that have shown a “trend reversal” from the long term to the short term (either
changing from erosion to accretion or vice-versa);
generally assess the speed or magnitude of change; or
support or direct research investigations or planning purposes .
The materials presented should not be used to:
solely differentiate/explain the cause of change;
state with absolute certainty the magnitude or speed of change at a given location;
predict future rates and/or amount of change; or
develop engineering or design plans.*
* Without a review of the underlying data
Summary: Shorelines are continuously moving in response to winds, waves, tides, sediment supply, changes in
relative sea level, and human activities. As a result, shoreline changes are generally not constant
through time and frequently switch from erosion (landward migration) to accretion (waterward
migration) and vice versa. Cyclic and non-cyclic processes change the position of the shoreline over a
variety of timescales, from the daily and seasonal effects of winds and waves, to changes in sea level
spanning decades, or more. The shoreline "rate of change" statistics offered here reflect a cumulative
summary of the processes that altered the shoreline for the time period analyzed, and cannot be
attributed to any one (or more) drivers.
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Long-term rates (ca. 1880s - 2006) Long-term rates of shoreline change were determined using two methods. One approach fitted a least
squares regression line to all shoreline positions from the earliest (ca. 1880s) to the most recent (2006).
The rate of change is given by the slope of the regression line to the data. The calculation of linear
regression rates uses all shoreline data at a given location, but requires a minimum of three shorelines.
The rates calculated with many shoreline positions can increase confidence by reducing potential errors
associated with the source data, and fluctuating short-term changes. (Dolan, Fenster, & Holme, 1991)
The linear regression method for determining shoreline change rates assumes a linear trend of change
among the shoreline dates. However, in locations where shoreline change rates have not remained
constant through time, a linear trend would not exist. For example, a shoreline may exhibit accretion
over the first 100 years, but in later years, the shoreline may shift to an erosion trend. In these cases, it
is expected that using a linear model provides a poor fit to the data, and as a result the uncertainty
associated with these shoreline change rates is higher than those in which the trend is more linear.
A second approach calculated end-point rates representing the net change between the two shorelines
divided by the elapsed time period. Unlike the linear regression method, end point rates do not have an
associated expression (such as a confidence interval) of how scattered the shoreline positions are
relative to an assumed linear trend, nor do they use any more than two shorelines. However, they can
be used where the required number of shorelines will not support the linear regression approach and
thus can provide a potentially more robust suite of data.
In both cases, negative rate values indicate erosion (movement of the shoreline away from a predefined
baseline) and positive rate values indicate accretion (movement of the shoreline towards the baseline.)
The baseline, described in more detail in the Data Processing section of this document, is simply a
reference datum from which to measure change.
Short-term rates (1983 – 2006) Typically, shoreline change occurring over a short time span can be characterized by cyclic or episodic
non-linear behavior, such as storm-induced shoreline erosion. High short-term variability increases the
shoreline change rate uncertainty and the potential for rates of shoreline change that are statistically
insignificant. In many locations, the short-term trend is calculated with only 3 shorelines. As noted
above, uncertainty generally decreases with an increasing number of shoreline data points; thus the
small number of shorelines in the short-term calculation can result in higher uncertainty.
Since the short-term timeframe considers comparatively less data than the long-term, the rate
calculation only used an end point rate. End point rates represent the net change between the two
shorelines divided by the elapsed time period. Unlike the linear regression method, end point rates do
not have an associated expression (such as a confidence interval) of how scattered the shoreline
positions are relative to an assumed linear trend.
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As with the long-term rates, negative rate values indicate erosion (movement of the shoreline away
from the established baseline) and positive rate values indicate accretion (movement of the shoreline
towards the established baseline.)
Data Compilation: Vector based shoreline data was derived from the following sources:
1880s:
1) Connecticut Historic Shoreline 1880s* Vector layer derived from assorted scanned National
Oceanic and Atmospheric Administration (NOAA) Topographic Survey sheets ( T-sheet) images
(ca. 1880s ) provided to DEEP by NGS (http://tinyurl.com/l3obnfn) All shorelines (with the
exception of the New Haven harbor area) were hand digitized from T-sheets georeferenced for
this effort as part of a DEEP / UCONN collaboration
2) EC4B04-LIS* NOAA Shoreline Data Explorer (http://www.ngs.noaa.gov/NSDE/) Used to fill in
gaps of shoreline from missing T-Sheet scans for New Haven Harbor area
1900s:
1) CT1900A; CT1900B; CT1908A; CT1909A NOAA Shoreline Data Explorer
(http://www.ngs.noaa.gov/NSDE/) Vector data created by NOAA
1910s:
1) CT1915A NOAA Shoreline Data Explorer (http://www.ngs.noaa.gov/NSDE/) Vector data created
by NOAA
1930s:
1) CT132ELA; CT132FMA NOAA Shoreline Data Explorer (http://www.ngs.noaa.gov/NSDE/) Vector
data created by NOAA
1940s:
1) PH3148A; PH3148AZ; PH3148F; PH31B NOAA Shoreline Data Explorer
(http://www.ngs.noaa.gov/NSDE/) Vector data created by NOAA
1950s:
1) Connecticut Hydrography Line (1953)**; Connecticut Hydrography Line (1958)**; U.S.
Geological Survey (USGS) Quadrangle Based Digital Line Graph (DLG) Hydrography Line Data
provided by DEEP (http://tinyurl.com/lk5emx6) Coastal arcs extracted from statewide layer
based on best available date of USGS quad compilation.
2) PH142A; PH142B NOAA Shoreline Data Explorer (http://www.ngs.noaa.gov/NSDE/) Vector data
created by NOAA
1960s:
1) Connecticut Hydrography Line (1960)**; Connecticut Hydrography Line (1961)**; Connecticut
Hydrography Line (1964)**; Connecticut Hydrography Line (1967)**; Connecticut Hydrography
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Line (1968)**; USGS Quadrangle Based DLG Hydrography Line Data provided by DEEP
(http://tinyurl.com/lk5emx6) Coastal arcs extracted from statewide layer based on best
available date of USGS quad compilation.
2) PH6002; PH6007; PH6815 NOAA Shoreline Data Explorer (http://www.ngs.noaa.gov/NSDE/)
Vector data created by NOAA
1970s:
1) Connecticut Hydrography Line (1970)**; USGS Quad Based DLG Hydrography Line Data
provided by DEEP (http://tinyurl.com/lk5emx6) Coastal arcs extracted from statewide layer
based on best available date of USGS quad compilation.
1980s:
1) Connecticut Hydrography Line (1983)**; Connecticut Hydrography Line (1984)**; USGS Quad
DLG Hydrography Line Data provided by DEEP (http://tinyurl.com/lk5emx6) Coastal arcs
extracted from statewide layer based on best available date of USGS quad compilation.
2) CM8312; CM8315 NOAA Shoreline Data Explorer (http://www.ngs.noaa.gov/NSDE/) Vector data
created by NOAA
1990s:
1) NOAA Environmental Sensitivity Index (ESI) data - CT* NOAA ESI Inventory
(http://response.restoration.noaa.gov/esi) Vector data created by NOAA
2000s:
1) CT0401A**; CT0401B**; CT0410C**; CT0410D**; CT0410E** NOAA Shoreline Data Explorer
(http://www.ngs.noaa.gov/NSDE/) Vector data created by NOAA
* indicates the set itself provides coast-wide coverage.
** indicates a set, that when combined with others, provides coast-wide coverage.
It is important to note that the variety of data sources used employed different methodologies for
deriving a shoreline. Moreover, the representation of what the shoreline is relative to the actual mark
on the ground also varied and can be classified into two characterizations:
1) Office of Coast Survey/NOAA T-Sheets (Topographic Survey Sheets – “T-Sheets”):
Mean High Water (MHW): By definition, this is the average of the two daily high water lines for areas in
a diurnal tidal cycle. On T-sheets from the Atlantic coast it is interpreted by trained topographers using
the physical appearance of the beach, usually a line from the preceding high water limit. (Shalowitz,
1962)
2) USGS 1:24K Topographic Quad Sheets:
Wet/Dry Line: These are best described as the “wet/dry line” or the intersection of land and water as
interpreted from the source material - typically aerial photos. Depending on the tide stage when the
photography was taken, the wet/dry line and MHW may not be exactly the same.
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Discussions with USGS-Woods Hole validate the rationale to use shorelines taken from disparate sources
and timeframes, with the increase in available data outweighing the drawbacks of using data derived
from different methodologies or referencing different shorelines. (Thieler & Himmestoss, DEEP/UCONN
meeting with USGS - Woods Hole, 2013) Successful integrations of such data were used in studies in
California, with the caveat being to responsibly address issues of errors in uncertainty. This is addressed
in a following section. (Hapke, Reid, Richmond, Ruggiero, & List, 2006)
General Shoreline Archive All source material was first converted (when necessary) into a common coordinate system (CT State
Plane (ft) NAD83.) The source material was then organized by grouping unique feature classes by
decade. For NOAA shoreline data this designation was predicated on the stated survey date provided
with the data attribution. For USGS data, the statewide line data was classified by a USGS Quadrangle
Index cross referenced against source material dates from scans of the original Topographic map scans
(Figure 1.) Next, the unique feature classes from each decade were imported in into a standardized data
schema based on a combination of NOAA shoreline attributes as well as attributes required by the
software package used to support the change analysis. Where needed, attribute values were
transferred or reclassified based on comparable native values. The standardized layers were then
merged into a data layer for each decade. The decadal layers were then merged into a statewide master
coverage (Figure 2.) All variants – original source material, decadal-based merges, and the entire
statewide datalayer - were stored within an Environmental Systems Research Institute (ESRI)
Geodatabase format to serve as a master archive of data suitable for supporting a variety of possible
uses.
Figure 1: Coastal USGS Quads by Year
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Figure 2: Sample shoreline data
Uncertainty Estimates The numerous potential errors involved in deriving shoreline data make it necessary to provide a best
estimate of the total positional uncertainty associated with each shoreline position. Uncertainties for
shorelines include errors introduced by data sources as well as errors introduced by measurement
methods and are well documented: (Anders & Byrnes, 1991) (Crowell, Leatherman, & Buckley, 1991)
(Thieler & Danforth, 1994); (Moore, 2000) (Ruggiero, Kaminsky, & Gelfenbaum, 2003). The following five
components are considered when estimating the positional uncertainty for shorelines:
1) georeferencing uncertainty;
2) digitizing uncertainty;
3) T-sheet survey uncertainty;
4) air photo collection and rectification uncertainty; and
5) the uncertainty of the high water line at the time of survey (Crowell, Leatherman, & Buckley,
1991)
For each shoreline, the position uncertainty is defined as the square root of the sum of squares (Taylor,
1997) of the relevant uncertainty terms, based on an assumption that each term is random and
independent of the others (Hapke, Himmelstoss, Kratzmann, List, & Thieler, 2010). The average values
for each uncertainty term and the total average positional uncertainty were estimated for each
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shoreline type (Table 1) using methods described in (Hapke, Himmelstoss, Kratzmann, List, & Thieler,
2010).
* USGS DLG Topo uncertainty value based on review of CT data, above citations, and personal communication with USGS
WHOI staff. Uncertainty value used is an average of upper and lower error bounds (15m and 30m)
** NOAA CT ESI source photo uncertainty taken from CT 1990 DOQQ positional accuracy assessments; assumes the same
values for ESI overflights
Shoreline Change Analysis Data A separate version of the master archive was extracted to specifically support the shoreline change
analysis described here. This dataset differs from the master archive in the following ways:
Vectors only correspond to lines classified as “Shoreline” based on representative values from the
standard attribute schema field describing the classification of the linework (i.e., this layer omits
lines classified as upland marsh boundaries, transportation features, hazard areas, etc. that were
included in some of the original source material).
The coordinate system was converted to UTM Zone 18 (meters) to conform to the requirements of
the software analysis package used.
Data Review/Assessment The review of shoreline change analysis data began by creating a buffer around the shorelines using the
appropriate error estimates. This provided a window of reasonable position to compare the shoreline
to other sources of coastal information and assess whether or not to include it.
Visual inspection of buffered lines:
1. For shorelines 1990 – present, it was possible to compare the shorelines to the actual
orthophoto imagery used to derive them (or to orthophotos taken within a year of the linework
at a comparable level of detail) to confirm if the linework was suitable. “Suitable” areas were
typically defined by:
Measurement Errors (m) Tsheets UDGS DLG Topo NOAA CT ESI Air Photos
1880s-1950s
1960s-1980s
1950s-1960s
1970s-1980s
1990s DOQQ /
ESI Flights 1995
CTDEP 1970-2000s
Georeferencing 4 4 4 4 0 4 0
Digitizing 1 1 1 1 1 1 1
Tsheet survey 10 3 0 0 0 0 0
Air Photos 0 0 0 0 10** 3 3
USGS DLG Topo 0 0 22.5* 22.* 0 0 0
Shoreline location 4.5 4.5 4.5 4.5 4.5 4.5 4.5
Square root of Sum of Squares (m) 11.72 6.80 23.31 23.31 11.01 6.80 5.50
Square root of Sum of Squares (ft) 38.43 22.31 76.47 76.47 36.12 22.31 18.04
Table 1: Uncertainty Terms
Table 1: Uncertainty Terms
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The error-bounded shoreline capturing what could best be determined as the “MHW
vicinity” – i.e., an area that captures the land-water interface as well as a portion
landward. In this way, we can be reasonably confident that the error-bounded
shoreline is close to MH or a high-water mark and at least above low-water. This metric
is typically applied to areas of open coastline such as beaches or marshes that do not
have a well-defined point of reference such as jetties, groins, rocky outcrops, seawalls,
rocky headlands, etc.
For areas of the coast that do have well-defined points of reference such as jetties,
groins, rocky outcrops, seawalls, rocky headlands, etc., the error-bounded shoreline
needed to overlap or reasonably define the shape, extent, or orientation of these
features.
Areas deemed “unsuitable” for this analysis generally corresponded to conditions such as:
Misinterpretations of the vicinity of MHW shoreline (e.g., exposed tidal flats or other
areas of obvious low water rather than a more appropriate area in the vicinity of the
beach/water interface );
Unknown/unexplainable digitizing errors such that the shorelines do not follow typical
interpretations used to define similar areas within the data.
Any unsuitable areas were coded as such during the review and removed from the final version
used in the analysis.
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Figure 3: Examples of suitable (top) and unsuitable (bottom) shoreline vectors.
In the top image of Figure 3, the blue shoreline generally follows the photo trend but more
importantly, the buffered area is also largely consistent. Below both the shoreline and the
buffered area do not provide a good visual match along the southern section of the land form.
2. For shorelines pre-dating 1990, it was not possible to replicate the same methodology described
above. Whereas the 1990-present shorelines were directly digitized from available (or
comparable) orthophotos, the shorelines pre-dating 1990 were digitized from scans of hardcopy
maps – T-sheets and USGS Topographic Quadrangle maps. These scanned maps required an
intermediary step to georeference them (referencing the image coordinates of the scan to real-
world coordinate locations,) which introduced an additional source of error. So while it was
possible in many cases to access the scanned maps and assess whether the shoreline was
interpreted and/or traced correctly, this alone was not sufficient to assess whether the
georeferencing process accurately located the maps to correspond to a reasonable location on
the ground. In order to assess the validity of the georeferencing, the error-bounded lines were
displayed over ca. 2010 orthophotography and examined along areas of the coast with well-
defined common points of reference such as jetties, groins, rocky outcrops, seawalls, rocky
headlands, etc., that were assumed to be constant over time. Fortunately the Connecticut
coastline has a well distributed set of these features enabling a coast-wide approach. The error-
bounded shoreline needed to overlap or reasonably define the shape, extent, or orientation of
these features in order to be considered suitable. In many cases, historic shorelines exhibited
an offset from these “constants” such that the overall configuration of the shoreline was
adequately represented, but the spatial location was shifted too far east, west, north or south -
indicating positional accuracy exceeded the error bounds. In these cases, the discrepant
shorelines were coded as unsuitable during the review and removed from the final version used
in the analysis. It should be noted that while this approach was employed coast-wide, it was
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necessarily limited in scope to areas that provided the means to assess the data; it is therefore
possible that some shorelines included in the analysis may exceed their stated positional error
boundary estimates. However, there was no conclusive way to identify or quantify these within
the constraints of this study’s time and funding, so taking a conservative approach in the
analysis aspect of this effort was employed.
Data Processing:
Overview Data processing used USGS Digital Shoreline Analysis System (DSAS) version 4.3 software extension for
ESRI ArcGIS. (Thieler, Himmelstoss, Zichichi, & Ergul, 2009) DSAS generates geospatial data and
statistical calculations for shoreline time-series data by analyzing the proximity and distribution of
shorelines from an established baseline (starting point) at user-defined intervals (transects.) DSAS
provides great flexibility in establishing parameters; consultations with USGS – Woods Hole staff (Thieler
& Himmestoss, DEEP/UCONN meeting with USGS - Woods Hole, 2013) provided the following best-
practices guidelines:
Locating baselines:
o Baselines should be oriented as close to shore as possible to minimize issues with multiple
transect crossings and drawn to force transects to be as orthogonal to shoreline trends as
possible. There is no “golden rule” and there will always be some interpretive work here. If
the above two criteria are held to, there’s very little difference in the resulting analyses –
i.e., similar baselines will produce essentially similar results.
o It is generally easier to create baselines for large stretches of shore and then edit/remove
transects from analysis rather than a series of shorter baselines that ignore certain areas.
Transect intervals:
o A typical interval of 50m will produce suitable data. This is what was used in Massachusetts,
could be more or less as needed.
Statistical derivations;
o Do not use WLR (weighted linear regression) calculations. Application of weighting
parameters in the coding is not done well enough to provide defensible results.
o Do not use EPR (end point rate) Confidence Interval values –values do not provide realistic
meaning.
o Ordinary least squares is the preferred statistic for anything >= 3 shorelines. Use EPR when
you only have two shorelines.
Other points of consideration
o Using as many shorelines as possible, even if they do not match the datum exactly, is more
useful in the data analysis. Adjusting the uncertainty values can help mitigate datum related
inconsistencies. Shorelines from USGS topographic maps have been mixed in with NOAA
shorelines in California – reports exist with the uncertainties used for those studies that we
have adopted/modified. (Hapke, Reid, Richmond, Ruggiero, & List, 2006)
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o Any photo derived shoreline can safely be assumed to use a wet/dry line which can be
considered comparable to MHW. Care should be taken to account for additional
uncertainty if there is any specific notation of only using a low-water line interface. Adjust
uncertainty as needed.
o Better to adjust uncertainty values than edit lines that do not “match” known shoreline
features like rocks, outcrops, etc. If data have systemic errors, then consider omitting all or
parts. General rule is to keep what can reasonably be kept, and adjust uncertainty.
o Using LIDAR derived shorelines is typically only useful in areas of consistently sloping sandy
beaches. For Connecticut, using LIDAR to fill in gaps of coverage in the eastern part of the
state is not likely a good use of time/effort as results may not be optimal. Better to acquire
USGS Topographic shorelines or NOAA ESI data as noted above.
o May want to consider looking at shorelines of similar type (i.e., sandy beach or marsh) to
examine comparing apples to apples.
o Calculating an “average” rate for a given aggregation of shoreline (i.e., a town, a county,
etc.) is doable, but this will likely be using shorelines of varying geologic characteristics. So
for example, any area of geologic stability over time will drive values down from areas of
actual erosion.
In general the outcome was to develop data for use in addressing two fundamental questions: “How
much has the shoreline changed?” (How far has it moved?) and “How fast has the shoreline
changed?” (At what rate is it moving?)
Baseline Development A baseline is used in the DSAS model as a starting point to create transects which then cross through the
individual shoreline vectors and provide measures of change over time. All baseline segments were
created at a distance offshore of the furthest seaward shoreline vector for all of the available years yet
oriented close enough to ensure that transects are reasonably perpendicular to the primary direction of
change. Segments of the baseline contain attributes to identify sections for individual analysis and
codes to provide a directional sequence for the model (west to east).
The baseline was created and edited within an ESRI file geodatabase (gdb) as a line feature. The file
geodatabase format maintains curve topology and provides additional functionality to easily create and
modify the line feature during the development and maintain a record of editing history. Once
completed this file geodatabase feature was exported to an ESRI personal geodatabase (mdb) for
compatibility with the DSAS modeling program.
An ESRI ArcGIS project was built for editing the baseline using additional feature layers for visible
reference in the background. The primary background layers were the available shoreline vectors for
each year, aerial imagery, and political boundaries helpful for identifying the attributes and positions of
the existing shorelines. To improve computer performance all shoreline vectors were cropped (clipped)
to a study zone created using a data layer that extends the town boundaries off shore far enough to
include all islands associated with a political boundary. The 24 coastal towns were selected and the
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feature was modified to extend beyond the western and eastern most towns. The baseline and final
analysis were contained within this clipped “zone”.
Before creating the baseline the shorelines were reviewed for what would eventually be included in the
final analysis. The 2006 vector layer was more detailed than prior years and included islands and rock
features not identified in earlier layers. These islands were removed from the analysis, as if they were
not removed the output would have provided false rates of change where transects crossed these
features. For larger island features not included in the time analysis, the baseline was drawn to fall
between the island and the furthest seaward shoreline, essentially removing the island from the results.
These offshore islands may affect the dynamics of the neighboring shoreline and provide a reason for
change or stability yet do not contribute directly to the calculations of change. The baseline was also
adjusted to avoid islands visible in the aerial imagery yet not identified in any of the vector datasets.
The Connecticut shoreline is very complex, it is not a simple linear feature where a baseline can easily
remain perpendicular to all of the shoreline features. Curved arcs were used to best align around
peninsulas and within embayments where straight-line baseline segments would not work. The DSAS
software does interpolate a curve for quick changes in baseline direction, however, pre-setting the arcs
allows for more control of the output transects, improving the odds the result transects would intersect
the shoreline features properly. Testing with intermediate runs of the DSAS software, then adjusting
the curves, improved the results.
Baseline Attributes: The attribute information within the baseline was coded to match political town
boundaries based on the starting point of a given line segment moving from West to East. The
shoreline towns were numbered west to east, starting in Greenwich with the number 1 and ending in
Stonington as 24. These codes were entered as attributes and each segment within a town was
numbered from 1 to the final segment count for that town (group sub-order). The segments were
broken at significant changes in the land features and shoreline directions. If a segment extended into
the next town the segment was broken, ensuring the attribute code changed at the boundary.
Important baseline attributes:
ID (LONG) – Primary unique identifier for DSAS. 100 plus Town order concatenated with 100 plus
group sub order. Adding 100 maintains a six digit format. Sample: Greenwich (Town 1) Segment #
3 = 101103
DSASGROUP (LONG) – Group value for optional use in DSAS. Value is the town number as identified
by DEEP.
CastDir (SHORT) – Value tells DSAS if the baseline segment is offshore (0) or inland (1) of the
shoreline vectors. In this study all values were set to 0.
townOrder (SHORT) – Towns labeled as 1 to 24 from West to East. Value used in ID.
grpSubOrder (LONG) – Values 1 to the last segment for a given town (west to east). Value used in
ID.
Additional attributes were used during the build of the dataset to help maintain edit history, include
town information, and provide suggested transect lengths for individual sections.
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The draft baseline was converted to a personal geodatabase and reviewed for consistency and accuracy.
A few segments were subsequently adjusted to extend selected features and better align sections to
maximize perpendicular transects.
Transect & Statistical Generation For both long-term data (i.e., shorelines from ca. 1880 to 2006) and short-term data (i.e., shorelines
from 1983 to 2006) the following process steps were implemented within DSAS:
1. Transects were generated with 50m spacing.
2. Transect geometry reviewed; where necessary baselines were adjusted to correctly orient
transects; transects regenerated with modified baselines.
3. Initial Statistics (using a Confidence Interval of 1.5 standard deviations) and intersect points
based on revised transects were created. Confidence Interval was chosen to provide a balance
of quantity of data and quality of data. Higher Confidence Interval values provide quality data at
(generally) the expense of quantity and/or distribution of data; Lower Confidence Intervals will
generally produce more data but of lower quality.
4. Reviewed revised transects and coded certain classes for removal:
a. Transects that were too skewed (i.e., they did not sufficiently intersect the general trend
of the shorelines in a more or less perpendicular fashion;
b. Multiple transects hitting at or near the same location (e.g., around a point of land, or
where one baseline ends and the next adjacent one begins.)
5. Reviewed intersection table and removed erroneous points (typically when transects were long
enough to pick up inland shoreline arcs with distinctly different dates or in areas behind where
parts of shorelines were removed due to accuracy issues.) This effectively sets a corrected
inventory of shoreline intersections.
6. Clipped revised transects based on the corrected intersect points to produce a set showing only
the envelope of change (limiting the transect length to just the area between the closest and
furthest shorelines from the baseline)
7. Used the clipped transects to generate revised (final) statistics; joined statistics table to clipped
transects to create a final analysis data set via the [ObjectId] field. Statistical output included:
a. Net Shoreline Movement (NSM): The net shoreline movement reports a distance, not a
rate. The NSM is associated with the dates of only two shorelines. It reports the distance
between the oldest and youngest shorelines for each transect. This represents the total
distance between the oldest and youngest shorelines.
b. End Point Rate (EPR): The end point rate is calculated by dividing the distance of
shoreline movement by the time elapsed between the oldest and the most recent
shoreline. The major advantages of the EPR are the ease of computation and minimal
requirement of only two shoreline dates. The major disadvantage is that in cases where
more data are available, the additional information is ignored.
c. Confidence of End Point Rate (ECI): Generated, but ignored for this study per USGS-
Woods Hole.
July 2014 Page 17 of 29
d. Shoreline Change Envelope (SCE): The shoreline change envelope reports a distance, not
a rate. The SCE is the distance between the shoreline farthest from and closest to the
baseline at each transect. This represents the total change in shoreline movement for all
available shoreline positions and is not related to their dates.
e. Linear Regression Rate (LRR): A linear regression rate-of-change statistic can be
determined by fitting a least-squares regression line to all shoreline points for a
particular transect. The regression line is placed so that the sum of the squared residuals
(determined by squaring the offset distance of each data point from the regression line
and adding the squared residuals together) is minimized. The linear regression rate is
the slope of the line. The method of linear regression includes these features: (1) All the
data are used, regardless of changes in trend or accuracy, (2) The method is purely
computational, (3) The calculation is based on accepted statistical concepts, and (4) The
method is easy to employ (Dolan, Fenster, & Holme, 1991). However, the linear
regression method is susceptible to outlier effects and also tends to underestimate the
rate of change relative to other statistics, such as EPR (Dolan, Fenster, & Holme, 1991)
(Genz, Fletcher, Dunn, Frazer, & Rooney, 2007).
f. The R-squared statistic, or coefficient of determination, is the percentage of variance in
the data that is explained by a regression. It is a dimensionless index that ranges from
1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the
data. In other words, it reflects the linear relationship between shoreline points along a
given DSAS transect.
g. Standard Error of the Estimate: The standard error of the estimate measures the
accuracy of the predicted values of y by comparing them to known values from the
shoreline point data.
h. LRR 86.6% Confidence Interval: The standard error of the slope with confidence interval
(LCI for ordinary linear regression) describes the uncertainty of the reported rate. The
LRR rates are determined by a best-fit regression line through the sample data. The
slope of this line is the reported rate of change (in meters/year). The confidence interval
(LCI) is calculated by multiplying the standard error (also called the standard deviation)
of the slope by the two-tailed test statistic at the user-specified confidence percentage
(Zar, 1999). The specific confidence interval was chosen to provide a balance between
quantity of data and quality of data.
8. Identified transects as:
a. Not statistically valid (e.g., where the LRR Confidence interval exceeded the LRR value),
b. Part of heavily industrialized harbors (Bridgeport, New Haven, Thames River) or areas of
significant fill (largely localized in the western 6 coastal communities) based on a review
of ca. 2010 aerial photographs and shoreline vectors.
c. Suitable for analysis – effectively those that were not coded as ‘a’ or ‘b’ above.
NOTE: all transects were used to assess net shoreline movement to track and display the
magnitude of shoreline change over time. The transects coded as described in 8a and 8b
July 2014 Page 18 of 29
above were omitted from any rate-based assessments as we felt the changes derived from
the obvious areas of heavy industrialization and fill would skew the overall results.
9. Added shoreline districts outlined in a 1979 CTDEP shoreline assessment to ID similar sections of
shoreline for organization and comparative purposes. (Connecticut Coastal Area Management
Program, 1979) (Figure 4) From west to east the following districts are defined as:
a. Rock and Drift/Much Artificial Fill
b. Glacial Drift and Beaches
c. Glacial Drift and Rock
d. Rock and Marshes
e. Glacial Drift and Beaches
f. Glacial Drift and Rock
g. Rock and Marshes
Figure 4: Connecticut Shoreline Districts
10. To account for a desire to address regional averaging of rates and uncertainties in the shoreline
change data (e.g., by geologic categorization or by town/political boundaries) we needed to
address how uncertainty values of each individual shoreline change value is used in the mean.
(Hapke, Himmelstoss, Kratzmann, List, & Thieler, 2010) In shorelines generally dominated by
long stretches of uniform orientation and geomorphology, it is possible to make use of
automated processes such as spatially lagged autocorrelation tools in commercial off the shelf
software packages. Given that the nature of the Connecticut shoreline does not match with
July 2014 Page 19 of 29
these conditions, discussions with USGS – Woods Hole (List, 2013) led to a manual best-
professional judgment routine within ArcGIS to identify self-similar stretches of shoreline
(typically defined by unique littoral cells such as pocket beaches and smaller stretches of beach
or marsh-dominated shorelines.) The identification of these “reduced transect” estimators was
used when determining regional uncertainty averages.
The resulting data show in Figures 5 – 7 were subsequently generated:
Figure 5: Final Data Structure output
July 2014 Page 20 of 29
Figure 6: Example of baselines, shoreline vectors, and analysis transects
Figure 7: Example of shoreline transects clipped to the shoreline change envelope
July 2014 Page 21 of 29
Statistical Review and Processing: Resulting data for both long and short-term rates were exported from ArcGIS into an MS Excel
spreadsheet for processing and analysis. Data were exported on the basis of shoreline districts as
defined above and organized using a combination of town identification codes and transect Ids to
provide an organized progression of transect data along the Connecticut coastline from west to east.
This enabled the generation of overall statistics for shoreline districts and the coastal communities
contained within.
Short-Term Data (1983 – 2006) For Short-term data (1983 – 2006), the following metrics were summarized on a per-town and district-
wide basis. In the vicinity of the Connecticut River we identify sections as fronting Long Island Sound
and the Connecticut River proper for towns on the western and eastern shores (Old Saybrook and Old
Lyme, respectively.) Here we only include the EPR, as the density of shoreline data is limited by the
temporal range and only small poorly distributed sections of the coast had the necessary number of
shorelines required to compute LRR-based statistics.
Net Shoreline Movement (how much has the shoreline moved): The Net Shoreline Movement
calculations included data from all transects in order to portray the overall characteristics of
change across the state and regions.
o Minimum
o Maximum
o Average
End Point Rate (how fast has the shoreline moved): The End Point Rate calculations excluded
data from transects corresponding to those coded as heavily urbanized or the likely result of
obvious fill in order to mitigate skewing the overall characteristics of rates of change across the
state and regions.
With respect the End Point Rate calculations, the following pros and cons are worth noting:
End Point Rate Pros:
A simple calculation that’s easily understandable;
Can be used essentially anywhere there are data (only need 2 shorelines.)
Easily applied to both Long Term and Short Term analyses
End Point Rate Cons:
Ignores other shorelines so the rate can be idealized;
Assumes a linear fit; not always the case
Can be highly influenced by the quality of either (or both) of the shorelines;
Provides no measure of confidence in the rate.
The Short-term data results are summarized below (Table 2). In cases where a community is split across
a shoreline district, we provide results for each component as well as a total:
July 2014 Page 22 of 29
Town NSM Min
NSM Max
NSM Ave
EPR Ave
Greenwich -23.88 45.43 1.21 0.06
Stamford -29.28 50.57 -1.91 -0.10
Darien -18.19 52.7 0.29 0.01
Norwalk - A -16.36 36.25 1.89 0.09
Zone A -29.28 52.7 0.60 0.03
Norwalk - A & B -24.08 36.25 1.33 0.06
Norwalk - B -24.08 19 -0.03 0.00
Westport -52.13 20.16 -3.90 -0.18
Fairfield -31.37 20.28 -5.12 -0.24
Bridgeport -30.51 92.65 -3.33 -0.23
Stratford -47.43 50.05 -5.56 -0.26
Milford - B -82.67 289.45 17.24 0.81
Zone B -82.67 289.45 -1.14 -0.06
Milford - B & C -82.67 289.45 8.09 0.38
Milford - C -64.07 37.08 -0.07 0.00
West Haven -73.53 140.46 -6.21 -0.24
New Haven - C -17.55 28.76 -4.55 N/A
Zone C -73.53 140.46 -3.54 -0.13
New Haven - C & D -18.05 28.76 0.03 0.02
New Haven - D -18.05 27.48 2.48 0.02
East Haven -7.78 32.33 1.15 0.05
Branford -26.52 21.45 0.82 0.04
Guilford - D -21.21 55.29 4.96 0.23
Zone D -26.52 55.29 2.45 0.10
Guilford - D & E -21.21 55.29 5.05 0.24
Guilford - E -16.99 36.16 5.71 0.35
Madison -40.11 11.88 -3.64 -0.17
Clinton -
133.55 29.91 -3.33 -0.15
Westbrook -12.12 19.51 2.14 0.10
Old Saybrook - LIS -19.89 23.8 -2.60 -0.12
Old Saybrook - CT River -20.51 25.83 6.18 0.28
Old Saybrook - All -20.51 25.83 0.75 0.03
Old Lyme - CT River - E -34.51 31.75 -9.81 -0.47
Old Lyme - LIS - E -
152.22 30.57 -14.05 -1.92
Old Lyme - E -
152.22 31.75 -12.28 -1.31
Zone E - 36.16 -3.04 -0.28
July 2014 Page 23 of 29
Town NSM Min
NSM Max
NSM Ave
EPR Ave
152.22
Old Lyme - E & F -
152.22 33.12 -9.41 -1.02
Old Lyme - F -12.51 33.12 1.35 0.08
East Lyme -36.44 32.53 -11.64 -0.50
Waterford -
120.77 19.63 -11.61 -0.56
New London -35.28 22.99 -6.23 -0.60
Groton - F -46.3 38.41 -3.34 -0.29
Zone F -
120.77 38.41 -7.04 -0.42
Groton - F & G -46.3 38.41 -3.33 -0.25
Groton - G -35.45 20.97 -3.32 -0.15
Stonington -71.72 34.02 -3.75 -0.17
Zone G -71.72 34.02 -3.68 -0.17 Table 2: Table of Short-term (1983 – 2006) statistics summary
Additional Short-Term products include the following (and are contained in Appendices)
Average Short-Term NSM Chart (by Town and District)
Long-Term Data (ca. 1880 – 2006) For Long-term data (ca. 1880 – 2006), the following metrics were summarized on a per-town and
district-wide basis. As there was a greater density of data due to the longer time horizon, there are
more data products. In the vicinity of the Connecticut River we identify sections as fronting Long Island
Sound and the Connecticut River proper for towns on the western and eastern shores (Old Saybrook and
Old Lyme, respectively.) As the long-term data generally have sufficient density across the entire coast,
we are able to compute both EPR and LRR-based statistics.
Net Shoreline Movement: The Net Shoreline Movement calculations included data from all
transects in order to portray the overall characteristics of change across the state and regions.
o Minimum
o Maximum
o Average
Linear Regression Rate: The Linear Regression Rate calculations excluded data from transects
corresponding to those coded as heavily urbanized or the likely result of obvious fill in order to
mitigate skewing the overall characteristics of rates of change across the state and regions.
o Minimum
o Maximum
o Average
Ave. Uncertainty (via reduced transect estimates)
July 2014 Page 24 of 29
End Point Rate: The End Point Rate calculations excluded data from transects corresponding to
those coded as heavily urbanized or the likely result of obvious fill in order to mitigate skewing
the overall characteristics of rates of change across the state and regions.
o Minimum
o Maximum
o Average
With respect to the rate of change calculations, the pros and cons are regarding the use of the End
Point rate are the same as those noted above in the Short-Term data section. Below are pro and con
points that are relevant for Linear Regression rates that are applied to the long-Term data:
Linear Regression Rate Pros:
Relatively easy to implement;
Uses all shoreline data;
Provides a rate and an estimate of confidence in it;
Allows user to specify level of confidence (in this case, 86.5% or 1.5 Standard Deviations)
Linear Regression Rate Cons:
Assumes a linear fit; not always the case
Requires at least 3 data points (ideally more)
Can return “inconclusive” results (e.g., where the measure of uncertainty is greater than the
rate) – requires user to interpret results
There may be areas where no output can be used.
The Long-term data results are summarized below (Table 3). In cases where a community is split across
a shoreline district, we provide results for each component as well as a total:
Town NSM Min
NSM Max
NSM Ave
EPR Ave LRR Ave
LRR CI Regional
Ave. Uncertainty
LRR CI Ave
Lower Bound
LRR CI Ave
Upper Bound
Greenwich -91.45 340.77 15.04 0.04 0.05 0.01 0.03 0.06
Stamford -64.3 416.78 17.34 0.05 0.06 0.03 0.03 0.08
Darien -112.49 196.13 6.24 0.02 0.04 0.01 0.02 0.05
Norwalk - A -49.63 436.05 19.15 0.05 0.05 0.02 0.03 0.07
Zone A -112.49 436.05 14.44 0.04 0.05 0.01 0.04 0.06
Norwalk - A & B -254.59 436.05 23.04 0.06 0.07 0.02 0.05 0.09
Norwalk - B -254.59 383.92 32.61 0.07 0.12 0.04 0.08 0.17
Westport -120.68 139.13 4.88 0.04 0.10 0.03 0.07 0.13
Fairfield -30.69 104.86 8.87 0.07 0.12 0.04 0.08 0.16
Bridgeport -51.62 343.97 42.82 0.22 0.28 0.05 0.23 0.33
Stratford -102.56 162.42 -12.52 -0.10 -0.06454 0.06452 -0.13 0.00
Milford - B -117.6 369.83 18.62 0.16 0.14 0.08 0.06 0.23
July 2014 Page 25 of 29
Town NSM Min
NSM Max
NSM Ave
EPR Ave LRR Ave
LRR CI Regional
Ave. Uncertainty
LRR CI Ave
Lower Bound
LRR CI Ave
Upper Bound
Zone B -254.59 383.92 16.04 0.07 0.12 0.02 0.10 0.13
Milford - B & C -117.6 369.83 16.63 0.06 0.06 0.03 0.03 0.09
Milford - C -95.07 42.95 -4.39 -0.04 -0.01 0.03 N/A N/A
West Haven -72.09 110.77 7.49 0.03 0.16 0.09 0.06 0.25
New Haven - C 11.96 791.13 430.63 0.03 N/A N/A N/A N/A
Zone C -95.07 791.13 64.98 0.00 0.08 0.04 0.04 0.12
New Haven - C & D -36.75 791.13 166.23 0.10 0.16 0.05 0.11 0.20
New Haven - D -36.75 353.85 43.59 0.10 0.16 0.06 0.10 0.21
East Haven -82.21 84.58 5.06 0.05 0.08 0.05 0.03 0.12
Branford -80.29 78.48 1.08 0.01 0.018 0.017 0.00 0.03
Guilford - D -203.67 111.53 -2.47 -0.02 -0.03 0.02 -0.06 -0.01
Zone D -203.67 353.85 6.97 0.01 0.02 0.01 0.01 0.03
Guilford - D & E -203.67 111.53 -8.02 -0.07 -0.08 0.02 -0.11 -0.06
Guilford - E -133.41 13.79 -43.43 -0.35 -0.39 0.13 -0.51 -0.26
Madison -204.63 63.34 -8.78 -0.07 -0.05 0.03 -0.08 -0.03
Clinton -183.71 45.96 -16.73 -0.14 -0.13 0.03 -0.16 -0.11
Westbrook -39.68 80.88 2.47 0.02 0.019 0.023 N/A N/A
Old Saybrook - LIS -67.15 212.89 -4.28 -0.03 -0.018 0.023 N/A N/A
Old Saybrook - CT River -26.34 258.34 11.95 0.10 0.09 0.07 0.02 0.15
Old Saybrook - All -67.15 258.34 1.86 0.01 0.022 0.024 N/A N/A
Old Lyme - CT River - E -77.74 65.36 -9.66 -0.08 -0.06 0.08 N/A N/A
Old Lyme - LIS - E -313.99 55.2 -43.26 -0.36 -0.31 0.09 -0.40 -0.21
Old Lyme - E -313.99 65.36 -30.03 -0.25 -0.21 0.07 -0.28 -0.14
Zone E -313.99 258.34 -11.46 -0.09 -0.08 0.02 -0.10 -0.07
Old Lyme - E & F -313.99 65.36 -25.27 -0.21 -0.18 0.05 -0.23 -0.13
Old Lyme - F -27.73 22.31 -6.90 -0.06 -0.064 0.058 -0.12 -0.01
East Lyme -97.03 70.77 -1.39 -0.01 0.03 0.04 N/A N/A
Waterford -129.06 87.26 -4.92 -0.08 -0.04 0.05 N/A N/A
New London -30.02 316.52 19.05 0.02 0.059 0.064 N/A N/A
July 2014 Page 26 of 29
Town NSM Min
NSM Max
NSM Ave
EPR Ave LRR Ave
LRR CI Regional
Ave. Uncertainty
LRR CI Ave
Lower Bound
LRR CI Ave
Upper Bound
Groton - F -74.01 249.38 10.74 -0.02 0.02 0.03 N/A N/A
Zone F -129.06 316.52 5.96 -0.03 0.00 0.02 N/A N/A
Groton - F & G -74.01 249.38 8.56 -0.01 0.03 0.02 0.00 0.05
Groton - G -37.59 52.34 2.06 0.02 0.04 0.03 0.01 0.08
Stonington -152.39 58.96 -5.89 -0.05 -0.02 0.01 -0.04 -0.01
Zone G -152.39 58.96 -4.53 -0.04 -0.01 0.012 N/A N/A Table 3: Table of Long-term (ca 1880 – 2006) statistics summary
Additional Long-Term products include the following (and are contained in Appendices)
Long-Term EPR &LRR and Short-Term EPR Averages Chart (by Town and District)
Average Long-Term NSM Chart (by Town and District)
District A:
o Long-term NSM Chart
o Long-term EPR Chart
District B:
o Long-Term NSM Chart
o Long-term EPR Chart
o Long-term LRR Chart
District C:
o Long-Term NSM Chart
o Long-term EPR Chart
o Long-term LRR Chart
District D:
o Long-Term NSM Chart
o Long-term EPR Chart
o Long-term LRR Chart
District E:
o Long-Term NSM Chart
o Long-term EPR Chart
o Long-term LRR Chart
District F:
o Long-Term NSM Chart
o Long-term EPR Chart
District G:
o Long-Term NSM Chart
o Long-term EPR Chart
o Long-term LRR Chart
July 2014 Page 27 of 29
Works Cited Anders, F. J., & Byrnes, M. R. (1991). Accuracy of shoreline change rates as determined from maps and
aerial photographs. Shore and Beach , 59, 17-26.
Connecticut Coastal Area Management Program. (1979). Shoreline Erosion Analysis and Recommended
Planning Process. Hartford: State of Connecticut, Department of Environmental Protection.
Crowell, M., Leatherman, S. P., & Buckley, M. K. (1991). Historical shoreline change; Error analysis and
mapping accuracy. Journal of Coastal Research , 7, 839-852.
Dolan, R., Fenster, M. S., & Holme, S. J. (1991). Temporal analysis of shoreline recession and accretion.
Journal of Coastal research , 7, 723-744.
Genz, A. S., Fletcher, C. H., Dunn, R. A., Frazer, L. N., & Rooney, J. J. (2007). The predictive accuracy of
shoreline change rate methods and alongshore beach variation on Maui, Hawaii. Journal of Coastal
Research , 23, 87-105.
Hapke, C. J., Himmelstoss, E. A., Kratzmann, M. G., List, J. H., & Thieler, E. R. (2010). National Assessment
of Shoreline ChangeL Historical Change along the New England and Mid-Atlantic Coasts. U.S. Geological
Survey.
Hapke, C. J., Reid, D., Richmond, B. M., Ruggiero, P., & List, J. (2006). National Assessment of Shoreline
Change Part 3: Historical Shoreline Change and Associated Coastal Land Loss Along Sandy Shorelines of
the California Coast. U.S. Geological Survey.
List, J. (2013 йил 21-November). Phone Conversation with USHS WHOI - Averaging Uncertainty. (K.
O'Brien, Interviewer)
Moore, L. (2000). Shoreline mapping techniques. Jounal of Coastal Research , 16, 111-124.
Ruggiero, P., Kaminsky, G. M., & Gelfenbaum, G. (2003). Linking proxy-based and datum-based
shorelines on a high-energy coastline: Implications for shoreline change analyses. Journal of Coastal
Research Special Issue 38 , 57-82.
Shalowitz, L. A. (1962). Shore and Sea Boundaries - with Special Reference to the Intepretation and Uses
of Coast and Geodectic Data (Vol. 2). Washington, DC: United States Goverenment Printing Office.
Taylor, J. R. (1997). An Introduction to Error Analysis: The Study of Uncertainties in Physical
Measurement. Sausalito, CA: University Science Books.
Thieler, E. R., & Danforth, W. W. (1994). Historical shoreline mapping (1). Improving techniques and
reducing positioning errors. Journal of Coastal Reseach , 10, 549-563.
Thieler, E. R., & Himmestoss, E. A. (2013 йил 5-April). DEEP/UCONN meeting with USGS - Woods Hole.
(K. O'Brien, & J. Stocker, Interviewers)
July 2014 Page 28 of 29
Thieler, E. R., Himmelstoss, E. A., Zichichi, J. L., & Ergul, A. (2009). Digital Shoreline Analysis System
(DSAS) version 4.0— An ArcGIS extension for calculating shoreline change. U.S. Geological Survey.
Zar, J. H. (1999). Biostatistical Analysis (4th ed ed.). Upper Saddle River, NJ: Prentice Hall.
Appendices:
1) Long-Term EPR, Long Term LRR, and Short-Term EPR Averages Chart (by Town and District)
2) Average Long-Term NSM Chart (by Town and District)
3) Average Short-Term NSM Chart (by Town and District)
4) District A:
a. Long-term NSM Chart
b. Long-term EPR Chart
5) District B:
a. Long-Term NSM Chart
b. Long-term EPR Chart
c. Long-term LRR Chart
6) District C:
a. Long-Term NSM Chart
b. Long-term EPR Chart
c. Long-term LRR Chart
7) District D:
a. Long-Term NSM Chart
b. Long-term EPR Chart
c. Long-term LRR Chart
8) District E:
a. Long-Term NSM Chart
b. Long-term EPR Chart
c. Long-term LRR Chart
9) District F:
a. Long-Term NSM Chart
b. Long-term EPR Chart
10) District G:
a. Long-Term NSM Chart
b. Long-term EPR Chart
c. Long-term LRR Chart
-2.00
-1.80
-1.60
-1.40
-1.20
-1.00
-0.80
-0.60
-0.40
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
Met
ers/
Year
Long Term (1880 - 2006) & Short Term (1983 - 2006) Shoreline Change Rate Comparison:
All Zones
Average Long Term Regression Rate w/ 86.6% Confidence Interval Average Long Term End Point Rate Average Short Term End Point Rate
Zone A: Rock, Drift, Artificial Fill Zone B: Glacial Drift & Beaches Zone C: Glaicial Drift & Rock
Zone E: Glacial Drift & Beaches
Zone D: Rock & Marshes
Zone F: Glacial Drift & Rock Zone G:
Rock & Marshes
A
B
C D E
F G
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-100
-50
0
50
100
150
200
250
300
350
400
450
Met
ers
Long Term (1880 - 2006) Average Net Shoreline Movement: All Zones
Net Shoreline Movement
A
B
C D E
F G
Zone A: Rock, Drift, Artificial Fill Zone B: Glacial Drift & Beaches Zone C: Glaicial Drift & Rock
Zone E: Glacial Drift & Beaches
Zone D: Rock & Marshes
Zone F: Glacial Drift & Rock
Zone G: Rock &
Marshes
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-25
-20
-15
-10
-5
0
5
10
15
20
Met
ers
Net Shoreline Movement
A B
C D E F G
Short Term (1983 - 2006) Average Net Shoreline Movement: All Zones
Zone A: Rock, Drift, Artificial Fill Zone B: Glacial Drift & Beaches Zone C: Glaicial Drift & Rock
Zone E: Glacial Drift & Beaches
Zone D: Rock & Marshes
Zone F: Glacial Drift & Rock Zone G:
Rock & Marshes
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-200
-100
0
100
200
300
400
500
0001-57 0013-57 0025-57 0037-57 0049-57 0061-57 0073-57 0085-57 0097-57 0109-57 0121-57 0133-57 0146-57 0160-57 0175-57 0187-57 0199-57 0211-57 0224-57 0236-57 0248-57 0264-57 0277-57 0289-57 0303-57 0315-57 0327-57 0339-57 0352-57 0375-57 0391-57 0403-57 0417-57 0433-57 0447-57 0463-57 0475-57 0490-57 0504-57 0516-57 0528-57 0544-57 0556-57 0568-57 0580-57 0593-57 0605-57 0619-57 0634-57 0647-135 0659-135 0671-135 0686-135 0698-135 0710-135 0722-135 0736-135 0748-135 0760-135 0772-135 0784-135 0796-135 0808-135 0820-135 0832-135 0845-135 0858-135 0870-135 0882-35 0895-35 0911-35 0923-35 0936-35 0948-35 0960-35 0972-35 0987-35 1001-35 1014-35 1027-35 1040-35 1054-35 1067-35 1081-35 1093-35 1109-35 1123-35 1137-35 1150-35 1163-35 1175-103 1187-103 1199-103 1214-103 1228-103 1240-103 1252-103 1264-103 1276-103 1289-103 1301-103 1314-103 1326-103 1340-103 1352-103 1364-103 1376-103 1388-103 1401-103 1413-103
Net
Sho
relin
e M
ovem
ent (
met
ers)
Transect Order (west to east)
Long Term (1880 - 2006) Net Shoreline Movement: Zone A - Rock, Drift, & Artificial Fill
Net Shoreline Movement (Positive) Net Shoreline Movement (Negative)
Greenwich: + 15.04 m
Darien: + 6.24 m
Norwalk*: + 19.15 m
Minimum Net Shoreline Movement: - 112.49 m Maximum Net Shoreline Movement: + 436.05 m
Average Net Shoreline Movement: + 14.44 m
* Only includes portions of town in Zone A
Manressa Island
Cove Island Beach / Weed
Beach
Scott Cove Shippan
Point
West Beach / Cummings
Beach
Darien River
Stamford Harbor
Greenwich Cove
Cook Point
Cos Cob Harbor
Indian Harbor
Greenwich Harbor
Field Point
Byram Harbor
Byram Point
Dolphin Cove
Greenwich Point / Green wich Point Beach
Stamford: + 17.34 m
Contentment / Butlers Islands Roton / Noroton Point
Five Mile River
Long Neck Point
Wilson Cove
Norwalk River
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-1.5
-1
-0.5
0
0.5
1
1.5
2
0001-57 0013-57 0025-57 0037-57 0049-57 0061-57 0073-57 0085-57 0097-57 0109-57 0121-57 0133-57 0146-57 0160-57 0175-57 0187-57 0199-57 0211-57 0224-57 0236-57 0248-57 0264-57 0277-57 0289-57 0303-57 0315-57 0327-57 0339-57 0352-57 0375-57 0391-57 0403-57 0417-57 0433-57 0447-57 0463-57 0475-57 0490-57 0504-57 0516-57 0528-57 0544-57 0556-57 0568-57 0580-57 0593-57 0605-57 0619-57 0634-57 0647-135 0659-135 0671-135 0686-135 0698-135 0710-135 0722-135 0736-135 0748-135 0760-135 0772-135 0784-135 0796-135 0808-135 0820-135 0832-135 0845-135 0858-135 0870-135 0882-35 0895-35 0911-35 0923-35 0936-35 0948-35 0960-35 0972-35 0987-35 1001-35 1014-35 1027-35 1040-35 1054-35 1067-35 1081-35 1093-35 1109-35 1123-35 1137-35 1150-35 1163-35 1175-103 1187-103 1199-103 1214-103 1228-103 1240-103 1252-103 1264-103 1276-103 1289-103 1301-103 1314-103 1326-103 1340-103 1352-103 1364-103 1376-103 1388-103 1401-103 1413-103
End
Poin
t Rat
e (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) End Point Rates: Zone A - Rock, Drift, & Artificial Fill
End Point Rate (Positive) End Point Rate (Negative)
Greenwich: + 0.04 m/yr
Darien: + 0.02 m/yr
Norwalk*: + 0.05 m/yr
Minimum End Point Rate: - 1.26 m/yr Maximum End Point Rate: + 1.62 m/yr
Average End Point Rate: + 0.04 m/yr
* Only includes portions of town in Zone A
Manressa Island
Cove Island Beach / Weed
Beach
Scott Cove
Shippan Point
West Beach / Cummings Beach
Darien River
Stamford Harbor
Greenwich Cove
Cook Point
Cos Cob Harbor
Indian Harbor Greenwich
Harbor
Field Point
Byram Harbor
Byram Point
Dolphin Cove
Greenwich Point / Green wich Point
Beach
Stamford: + 0.05 m/yr
Contentment / Butlers Islands
Roton / Noroton
Point
Five Mile River
Long Neck Point
Wilson Cove
Norwalk River
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
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1421-103 1431-103 1441-103 1452-103 1463-103 1475-103 1485-103 1495-103 1505-103 1515-103 1525-158 1536-158 1546-158 1556-158 1569-158 1579-158 1589-158 1599-158 1609-158 1619-158 1629-158 1639-158 1649-158 1659-158 1670-158 1680-158 1690-158 1700-158 1710-158 1720-158 1730-158 1741-158 1751-158 1763-158 1773-158 1783-158 1793-158 1804-158 1814-158 1824-158 1834-51 1844-51 1855-51 1865-51 1877-51 1887-51 1898-51 1908-51 1918-51 1928-51 1938-51 1950-51 1960-51 1970-51 1980-15 1990-15 2000-15 2010-15 2021-15 2031-15 2041-15 2051-15 2062-15 2072-15 2082-15 2092-15 2102-15 2112-15 2122-15 2132-15 2145-15 2159-15 2169-15 2179-15 2189-15 2200-15 2210-15 2224-15 2235-15 2245-15 2255-15 2265-138 2275-138 2285-138 2295-138 2305-138 2315-138 2325-138 2335-138 2345-138 2355-138 2365-138 2386-138 2400-138 2410-138 2422-138 2432-138 2445-84 2457-84 2467-84 2477-84 2487-84 2497-84 2507-84 2517-84 2527-84 2537-84 2547-84 2557-84 2567-84 2577-84
Net
Sho
relin
e M
ovem
ent (
met
ers)
Transect Order (west to east)
Long Term (1880 - 2006) Net Shoreline Movement: Zone B - Glacial Drift & Beaches
Net Shoreline Movement (Positive) Net Shoreline Movement (Negative)
Norwalk*: + 32.61 m
Westport: + 4.88 m
Fairfield: + 8.87 m
Bridgeport: + 42.82 m
Milford*: + 18.62 m
Stratford: - 12.52 m
Minimum Net Shoreline Movement: - 254.59 m Maximum Net Shoreline Movement: + 383.92 m
* Only includes portions of town in Zone B
Fort Trumbull Beach
Wildemere / Walnut Beaches
Silver Sands State Park
Milford Point / Cedar Beach
Short Beach
Long Beach
Pleasure Beach
Seaside Park Beach
Jennings Beach
Fairfield Beach
Pine Creek Point
Sasco Hill / Sasco
Beaches
Frost Point / Burial Hill Beach
Alvord / Shrewood Island
Beaches
Canfield Island / Seymour Point
Saugatuck River / Harbor
Fitch Point
Calf Pasture Point
Black Rock Harbor
Lordship Beach
Bridgeport Harbor Analysis of Shoreline Change in Connecticut: 100 Years of
Erosion & Accretion A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-1.5
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-0.5
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0.5
1
1.5
2
2.5
3
3.5
1421-103 1431-103 1441-103 1452-103 1463-103 1475-103 1485-103 1495-103 1505-103 1515-103 1525-158 1536-158 1546-158 1556-158 1569-158 1579-158 1589-158 1599-158 1609-158 1619-158 1629-158 1639-158 1649-158 1659-158 1670-158 1680-158 1690-158 1700-158 1710-158 1720-158 1730-158 1741-158 1751-158 1763-158 1773-158 1783-158 1793-158 1804-158 1814-158 1824-158 1834-51 1844-51 1855-51 1865-51 1877-51 1887-51 1898-51 1908-51 1918-51 1928-51 1938-51 1950-51 1960-51 1970-51 1980-15 1990-15 2000-15 2010-15 2021-15 2031-15 2041-15 2051-15 2062-15 2072-15 2082-15 2092-15 2102-15 2112-15 2122-15 2132-15 2145-15 2159-15 2169-15 2179-15 2189-15 2200-15 2210-15 2224-15 2235-15 2245-15 2255-15 2265-138 2275-138 2285-138 2295-138 2305-138 2315-138 2325-138 2335-138 2345-138 2355-138 2365-138 2386-138 2400-138 2410-138 2422-138 2432-138 2445-84 2457-84 2467-84 2477-84 2487-84 2497-84 2507-84 2517-84 2527-84 2537-84 2547-84 2557-84 2567-84 2577-84
End
Poin
t Rat
e (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) End Point Rates: Zone B - Glacial Drift & Beaches
End Point Rate (Positive) End Point Rate (Negative)
Norwalk*: + 0.07 m/yr
Westport: + 0.04 m/yr
Fairfield: + 0.07 m/yr
Bridgeport: + 0.22 m/yr
Milford*: + 0.16 m/yr
Stratford: - 0.10 m/yr
Minimum End Point Rate: - 0.99 m/yr Maximum End Point Rate: +3.09 m/yr
Average End Point Rate: + 0.07 m/yr
* Only includes portions of town in Zone B
Wildemere / Walnut Beaches
Silver Sands State Park
Milford Point / Cedar Beach
Short Beach
Long Beach
Pleasure Beach
Seaside Park Beach
Penfield / Jennings Beach
Fairfield Beach
Pine Creek Point
Sasco Hill / Sasco
Beaches
Frost Point / Burial Hill Beach
Alvord / Shrewood Island
Beaches
Canfield Island / Seymour Point
Saugatuck River / Harbor
Calf Pasture Point
Black Rock Harbor
Lordship Beach
Bridgeport Harbor
Fort Trumbull Beach
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-1.5
-1
-0.5
0
0.5
1
1.5
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1421-103 1431-103 1441-103 1452-103 1463-103 1475-103 1485-103 1495-103 1505-103 1515-103 1525-158 1536-158 1546-158 1556-158 1569-158 1579-158 1589-158 1599-158 1609-158 1619-158 1629-158 1639-158 1649-158 1659-158 1670-158 1680-158 1690-158 1700-158 1710-158 1720-158 1730-158 1741-158 1751-158 1763-158 1773-158 1783-158 1793-158 1804-158 1814-158 1824-158 1834-51 1844-51 1855-51 1865-51 1877-51 1887-51 1898-51 1908-51 1918-51 1928-51 1938-51 1950-51 1960-51 1970-51 1980-15 1990-15 2000-15 2010-15 2021-15 2031-15 2041-15 2051-15 2062-15 2072-15 2082-15 2092-15 2102-15 2112-15 2122-15 2132-15 2145-15 2159-15 2169-15 2179-15 2189-15 2200-15 2210-15 2224-15 2235-15 2245-15 2255-15 2265-138 2275-138 2285-138 2295-138 2305-138 2315-138 2325-138 2335-138 2345-138 2355-138 2365-138 2386-138 2400-138 2410-138 2422-138 2432-138 2445-84 2457-84 2467-84 2477-84 2487-84 2497-84 2507-84 2517-84 2527-84 2537-84 2547-84 2557-84 2567-84 2577-84
Line
ar R
egre
ssio
n Ra
tes
(met
ers/
year
)
Transect Order (west to east)
Long Term (1880 - 2006) Valid Linear Regression Rates: Zone B - Glacial Drift & Beaches
Linear regression rate (Positive) Linear regression rate (Negative)
* Only includes portions of town in Zone B
Norwalk*: + 0.12 m/yr (+/- 0.04 m)
Westport: + 0.10 m/yr (+/- 0.03 m)
Fairfield: + 0.12 m/yr (+/- 0.04 m)
Bridgeport: + 0.28 m/yr (+/- 0.05 m)
Milford*: + 0.14 m/yr (+/- 0.08 m)
Stratford: N/A
Fort Trumbull Beach
Wildemere / Walnut Beaches
Silver Sands
State Park
Milford Point / Cedar Beach
Short Beach
Long Beach
Pleasure Beach
Seaside Park Beach
Jennings Beach
Fairfield Beach
Pine Creek Point
Sasco Hill / Sasco Beaches
Frost Point / Burial Hill Beach
Alvord / Sherwood Island
Beaches
Canfield Island
Saugatuck River / Harbor
Calf Pasture Beach / Point
Bridgeport Harbor
Penfield / Jennings Beach
Minimum Linear Regression Rate: - 0.94 m/yr Maximum Linear Regression Rate: + 2.57 m/yr
Average Linear Regression Rate: + 0.12 m/yr
Average Uncertainty (at 86.6% Confidence Interval:) +/- 0.02 m/yr
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
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300
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500
600
700
800
2581-84
2585-84
2589-84
2593-84
2597-84
2601-84
2607-84
2611-84
2615-84
2619-84
2624-84
2628-84
2632-84
2636-84
2640-84
2646-84
2650-84
2654-84
2658-84
2662-84
2666-84
2670-84
2674-84
2678-84
2682-84
2686-84
2690-84
2694-84
2698-84
2702-84
2706-84
2711-84
2716-84
2720-84
2724-84
2728-84
2732-84
2736-84
2740-84
2744-156
2748-156
2752-156
2756-156
2760-156
2764-156
2768-156
2772-156
2776-156
2780-156
2784-156
2788-156
2792-156
2796-156
2800-156
2804-156
2808-156
2812-156
2817-156
2822-156
2827-156
2831-156
2835-156
2839-156
2843-156
2847-156
2851-156
2855-156
2859-156
2863-156
2867-156
2871-156
2875-156
2879-156
2883-156
2887-156
2891-156
2895-156
2899-156
2903-156
2909-156
2913-156
2917-156
2921-156
2925-156
2931-156
2935-156
2939-93
2943-93
2947-93
2951-93
2957-93
2966-93
2970-93
2974-93
2978-93
2982-93
2986-93 2990-93
2996-93
3001-93
3005-93 N
et S
hore
line
Mov
emen
t (m
eter
s)
Transect Order (west to east)
Long Term (1880 - 2006) Net Shoreline Movement: Zone C - Glacial Drift & Rock
Net Shoreline Movement (Positive) Net Shoreline Movement (Negative)
Milford*: -4.39 m
New Haven*: + 430.63 m
Minimum Net Shoreline Movement: - 95.07 m Maximum Net Shoreline Movement: + 791.13 m
Average Net Shoreline Movement: + 64.98 m
* Only includes portions of town in Zone C
Sandy Point
West / Prospect Beaches
Bradley Point
East Beach
Woodmont
Anchor Beach Morningside Bayview / Point
Beaches
Burwells Beach
Gulf Beach
Rocky Beach
West Haven: + 7.49 m
City Point
Western New Haven Harbor
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-2
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2581-84
2585-84
2589-84
2593-84
2597-84
2601-84
2607-84
2611-84
2615-84
2619-84
2624-84
2628-84
2632-84
2636-84
2640-84
2646-84
2650-84
2654-84
2658-84
2662-84
2666-84
2670-84
2674-84
2678-84
2682-84
2686-84
2690-84
2694-84
2698-84
2702-84
2706-84
2711-84
2716-84
2720-84
2724-84
2728-84
2732-84
2736-84
2740-84
2744-156
2748-156
2752-156
2756-156
2760-156
2764-156
2768-156
2772-156
2776-156
2780-156
2784-156
2788-156
2792-156
2796-156
2800-156
2804-156
2808-156
2812-156
2817-156
2822-156
2827-156
2831-156
2835-156
2839-156
2843-156
2847-156
2851-156
2855-156
2859-156
2863-156
2867-156
2871-156
2875-156
2879-156
2883-156
2887-156
2891-156
2895-156
2899-156
2903-156
2909-156
2913-156
2917-156
2921-156
2925-156
2931-156
2935-156
2939-93
2943-93
2947-93
2951-93
2957-93
2966-93
2970-93
2974-93
2978-93
2982-93
2986-93
2990-93
2996-93
3001-93
3005-93 En
d Po
int R
ate
(met
ers/
year
)
Transect Order (west to east)
Long Term (1880 - 2006) End Point Rates: Zone C - Glacial Drift & Rock
End Point Rate (Positive) End Point Rate (Negative)
Milford:* - 0.04 m/yr
New Haven*,**: N/A
Minimum End Point Rate: - 1.73 m/yr Maximum End Point Rate: + 3.55 m/yr
Average End Point Rate: 0.00 m/yr
* only includes portion of townin Zone C ** No transects present viable rate data
Sandy Point
West / Prospect Beaches
Bradley Point
East Beach
Woodmont
Anchor Beach
Morningside Bayview / Point Beaches
Burwells Beach
Gulf Beach
Rocky Beach
West Haven: + 0.03 m/yr
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-1
-0.5
0
0.5
1
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2581-84
2585-84
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2593-84
2597-84
2601-84
2607-84
2611-84
2615-84
2619-84
2624-84
2628-84
2632-84
2636-84
2640-84
2646-84
2650-84
2654-84
2658-84
2662-84
2666-84
2670-84
2674-84
2678-84
2682-84
2686-84
2690-84
2694-84
2698-84
2702-84
2706-84
2711-84
2716-84
2720-84
2724-84
2728-84
2732-84
2736-84
2740-84
2744-156
2748-156
2752-156
2756-156
2760-156
2764-156
2768-156
2772-156
2776-156
2780-156
2784-156
2788-156
2792-156
2796-156
2800-156
2804-156
2808-156
2812-156
2817-156
2822-156
2827-156
2831-156
2835-156
2839-156
2843-156
2847-156
2851-156
2855-156
2859-156
2863-156
2867-156
2871-156
2875-156
2879-156
2883-156
2887-156
2891-156
2895-156
2899-156
2903-156
2909-156
2913-156
2917-156
2921-156
2925-156
2931-156
2935-156
2939-93
2943-93
2947-93
2951-93
2957-93
2966-93
2970-93
2974-93
2978-93
2982-93
2986-93
2990-93
2996-93
3001-93
3005-93 Li
near
Reg
ress
ion
Rate
(met
ers/
year
)
Transect Order (west to east)
Long Term (1880 - 2006) Valid Linear Regression Rates: Zone C - Glacial Drift & Rock
Linear Regression Rate (Positive) Linear Regression Rate (Negative)
Milford*: N/A
New Haven*,**: N/A
Minimum Linear RegressionRate: - 1.69 m/yr Maximum Linear Regression Rate: + 1.37 m/yr
Average Linear Regression Rate: + 0.08 m/yr (+/- 0.04 m)
Sandy Point
West / Prospect Beaches
Bradley Point
East Beach
Woodmont
Anchor Beach
Morningside
Burwells Beach
Gulf Beach
Rocky Beach
West Haven: + 0.16 m/yr (+/- 0.09 m)
* only includes portion of townin Zone C ** No transects present viable rate data
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-300
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3009-93 3016-93 3023-93 3031-93 3038-93 3045-93 3053-93 3060-93 3071-93 3078-93 3085-93 3092-93 3099-93 3106-93 3113-93 3120-93 3127-93 3134-93 3142-44 3149-44 3157-44 3164-44 3171-44 3181-44 3188-44 3195-44 3202-44 3210-44 3217-44 3224-44 3231-44 3238-44 3247-14 3260-14 3267-14 3275-14 3282-14 3289-14 3297-14 3304-14 3315-14 3324-14 3332-14 3339-14 3347-14 3355-14 3363-14 3370-14 3379-14 3386-14 3393-14 3401-14 3408-14 3419-14 3430-14 3437-14 3444-14 3451-14 3458-14 3465-14 3472-14 3479-14 3486-14 3493-14 3500-14 3507-14 3514-14 3521-14 3530-14 3539-14 3547-14 3554-14 3561-14 3572-14 3583-14 3591-14 3598-14 3605-14 3613-60 3620-60 3627-60 3634-60 3641-60 3649-60 3658-60 3665-60 3672-60 3679-60 3686-60 3694-60 3702-60 3710-60 3717-60 3724-60 3731-60 3738-60 3745-60 3752-60 3762-60 3769-60 3777-60 3785-60 3792-60 3799-60 3806-60 3813-60 3820-60 3827-60 3834-60 3841-60 3849-60 3857-60 3868-60 3875-60 3883-60 3890-60
Net
Sho
relin
e M
ovem
ent (
met
ers)
Transect Order (west to east)
Long Term (1880 - 2006) Net Shoreline Movement: Zone D - Rock & Marshes
Net Shoreline Movement (Positive) Net Shoreline Movement (Negative)
New Haven*: + 43.59 m
Guilford*: - 2.47 m
Minimum Net Shoreline Movement: - 203.67 m Maximum Net Shoreline Movement: + 353.85 m
Average Net Shoreline Movement: + 6.97 m
* Only includes portions of town in Zone D
Horton Point
Limewood Beaches
Hotchkiss Grove Beach
Pleasant Point
Lighthouse Point
Farm River
Silver Sands Beach / East Haven Town Beach
East Shore Park / Nathan Hale Park
Forbes Bluff
Eastern New Haven Harbor
Lindsey Cove
East Haven: + 5.06 m
Joshua Cove
Tuttle's Point / Chaffinch Island
Branford: + 1.08 m
Lighthouse Point Beach / Morgan Point / West
Silver Sands Beach
Johnson Point
Indian Neck Point
Hoadley Neck
Flying Point
Island Bay
Sachem Head
Indian Cove
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-2
-1.5
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1.5
2
3009-93 3016-93 3023-93 3031-93 3038-93 3045-93 3053-93 3060-93 3071-93 3078-93 3085-93 3092-93 3099-93 3106-93 3113-93 3120-93 3127-93 3134-93 3142-44 3149-44 3157-44 3164-44 3171-44 3181-44 3188-44 3195-44 3202-44 3210-44 3217-44 3224-44 3231-44 3238-44 3247-14 3260-14 3267-14 3275-14 3282-14 3289-14 3297-14 3304-14 3315-14 3324-14 3332-14 3339-14 3347-14 3355-14 3363-14 3370-14 3379-14 3386-14 3393-14 3401-14 3408-14 3419-14 3430-14 3437-14 3444-14 3451-14 3458-14 3465-14 3472-14 3479-14 3486-14 3493-14 3500-14 3507-14 3514-14 3521-14 3530-14 3539-14 3547-14 3554-14 3561-14 3572-14 3583-14 3591-14 3598-14 3605-14 3613-60 3620-60 3627-60 3634-60 3641-60 3649-60 3658-60 3665-60 3672-60 3679-60 3686-60 3694-60 3702-60 3710-60 3717-60 3724-60 3731-60 3738-60 3745-60 3752-60 3762-60 3769-60 3777-60 3785-60 3792-60 3799-60 3806-60 3813-60 3820-60 3827-60 3834-60 3841-60 3849-60 3857-60 3868-60 3875-60 3883-60 3890-60
End
Poin
t Rat
e (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) End Point Rate: Zone D - Rock & Marshes
End Point Rate (Positive) End Point Rate (Negative)
New Haven*: + 0.1 m/yr
Guilford*: - 0.02 m/yr
Minimum End Point Rate: - 1.66 m/yr Maximum End Point Rate: + 0.92 m/yr
Average End Point Rate: 0.01 m/yr
* Only includes portions of town in Zone D
Horton Point
Limewood Beaches
Hotchkiss Grove Beach
Pleasant Point
Lighthouse Point
Farm River
Silver Sands Beach / East Haven Town
Beach
East Shore Park / Nathan Hale
Park
Forbes Bluff
Lindsey Cove
East Haven: + 0.05 m/yr
Joshua Cove
Tuttle's Point / Chaffinch Island
Branford: + 0.01 m/yr
Lighthouse Point Beach / Morgan
Point / West Silver Sands Beach
Johnson Point
Indian Neck Point
Hoadley Neck
Flying Point
Island Bay
Sachem Head
Indian Cove
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative efort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
3009-93 3016-93 3023-93 3031-93 3038-93 3045-93 3053-93 3060-93 3071-93 3078-93 3085-93 3092-93 3099-93 3106-93 3113-93 3120-93 3127-93 3134-93 3142-44 3149-44 3157-44 3164-44 3171-44 3181-44 3188-44 3195-44 3202-44 3210-44 3217-44 3224-44 3231-44 3238-44 3247-14 3260-14 3267-14 3275-14 3282-14 3289-14 3297-14 3304-14 3315-14 3324-14 3332-14 3339-14 3347-14 3355-14 3363-14 3370-14 3379-14 3386-14 3393-14 3401-14 3408-14 3419-14 3430-14 3437-14 3444-14 3451-14 3458-14 3465-14 3472-14 3479-14 3486-14 3493-14 3500-14 3507-14 3514-14 3521-14 3530-14 3539-14 3547-14 3554-14 3561-14 3572-14 3583-14 3591-14 3598-14 3605-14 3613-60 3620-60 3627-60 3634-60 3641-60 3649-60 3658-60 3665-60 3672-60 3679-60 3686-60 3694-60 3702-60 3710-60 3717-60 3724-60 3731-60 3738-60 3745-60 3752-60 3762-60 3769-60 3777-60 3785-60 3792-60 3799-60 3806-60 3813-60 3820-60 3827-60 3834-60 3841-60 3849-60 3857-60 3868-60 3875-60 3883-60 3890-60
Line
ar R
egre
ssio
n Ra
te (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) Valid Linear Regression Rates: Zone D - Rock & Marshes
Linear Regression Rate (Positive) Linear Regression Rate (Negative)
New Haven*: + 0.16 m/yr (+/- 0.06 m)
Guilford*: - 0.03 m/yr (+/- 0.02 m)
Minimum Linear Regression Rate: - 1.82 m/yr Maximum Linear Regression Rate: + 0.87 m/yr
Average Linear Regression Rate: + 0.02 m/yr (+/- 0.01 m)
* Only includes portions of town in Zone D
Horton Point
Limewood Beaches
Juniper Point Farm River
Silver Sands Beach / East Haven Town Beach
Nathan Hale Park
Forbes Bluff
Lindsey Cove
East Haven: + 0.08 m/yr (+/- 0.05 m)
Joshua Cove
Tuttle's Point / Chaffinch Island
Branford: + 0.018 m/yr (+/- 0.017 m)
Lighthouse Point Beach / Morgan
Point / West Silver Sands Beach
Johnson Point
Indian Neck Point
Hoadley Neck
Flying Point
Island Bay
Joshua Point
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-400
-300
-200
-100
0
100
200
300
3893-60 3905-60 3915-60 3924-60 3935-60 3944-76 3953-76 3962-76 3972-76 3982-76 3991-76 4000-76 4010-76 4021-76 4030-76 4039-76 4048-76 4058-76 4067-76 4076-76 4086-76 4095-76 4104-76 4113-76 4122-76 4131-76 4140-76 4149-76 4158-76 4169-27 4178-27 4187-27 4196-27 4206-27 4215-27 4224-27 4233-27 4242-27 4252-27 4262-27 4271-27 4280-27 4289-27 4298-27 4307-154 4316-154 4325-154 4334-154 4343-154 4352-154 4361-154 4370-154 4379-154 4388-154 4397-154 4407-154 4417-154 4426-154 4438-106 4447-106 4457-106 4466-106 4475-106 4485-106 4494-106 4503-106 4512-106 4521-106 4530-106 4539-106 4548-106 4557-106 4566-106 4575-106 4584-106 4597-106 4606-106 4616-106 4625-106 4634-106 4643-106 4653-106 4664-106 4673-106 4682-106 4692-105 4701-105 4710-105 4719-105 4728-105 4737-105 4747-105 4760-105 4769-105 4778-105 4787-105 4796-105 4805-105 4814-105 4823-105 4833-105 4843-105 4852-105 4861-105 4870-105 4879-105 4888-105
Net
Sho
relin
e M
ovem
ent (
met
ers)
Transect Order (west to east)
Long Term (1880 - 2006) Net Shoreline Movement: Zone E - Glacial Drift & Beaches
Net Shoreline Movement (Positive) Net Shoreline Movement (Negative)
Guilford*: - 43.43 m
Madison: - 8.78 m
Clinton: - 16.73 m
Westbrook: + 2.47 m
Old Saybrook - LIS: - 4.28 m
Old Lyme - LIS*: - 43.26 m
Old Saybrook - CT River: + 11.95 m
Old Lyme - CT River: -9.66 m
Minimum Net Shoreline Movement: - 313.99 m Maximum Net Shoreline Movement: + 258.34 m
Average Net Shoreline Movement: - 11.46 m
Old Saybrook - All: +1.86 m
Old Lyme - All*: - 30.03 m
* Only includes portions of town in Zone E
Meigs Point, Hammonasset Beach
Cedar Island
Clinton Beach
Grove Beach
Chapman Point
Harvey'sBeach
Fenwood / Fenwick
Lynde Point
South Cove
North Cove
Ragged Rock Creek
Great Island
Griwold Point to White Sands Beach
Chaffinch Island
Grass Island
Surf Club
Beach
Webster Point
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3893-60 3905-60 3915-60 3924-60 3935-60 3944-76 3953-76 3962-76 3972-76 3982-76 3991-76 4000-76 4010-76 4021-76 4030-76 4039-76 4048-76 4058-76 4067-76 4076-76 4086-76 4095-76 4104-76 4113-76 4122-76 4131-76 4140-76 4149-76 4158-76 4169-27 4178-27 4187-27 4196-27 4206-27 4215-27 4224-27 4233-27 4242-27 4252-27 4262-27 4271-27 4280-27 4289-27 4298-27 4307-154 4316-154 4325-154 4334-154 4343-154 4352-154 4361-154 4370-154 4379-154 4388-154 4397-154 4407-154 4417-154 4426-154 4438-106 4447-106 4457-106 4466-106 4475-106 4485-106 4494-106 4503-106 4512-106 4521-106 4530-106 4539-106 4548-106 4557-106 4566-106 4575-106 4584-106 4597-106 4606-106 4616-106 4625-106 4634-106 4643-106 4653-106 4664-106 4673-106 4682-106 4692-105 4701-105 4710-105 4719-105 4728-105 4737-105 4747-105 4760-105 4769-105 4778-105 4787-105 4796-105 4805-105 4814-105 4823-105 4833-105 4843-105 4852-105 4861-105 4870-105 4879-105 4888-105
End
Poin
t Rat
es (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) End Point Rates: Zone E - Glacial Drift & Beaches
End Point Rate (Positive) End Point Rate (Negative)
Guilford*: - 0.35 m/yr
Madison: - 0.07 m/yr
Clinton: - 0.14 m/yr
Westbrook: + 0.02 m/yr
Old Saybrook - LIS: - 0.03 m/yr
Old Lyme - LIS*: - 0.36 m/yr
Old Saybrook - CT River: + 0.10 m/yr
Old Lyme - CT River: - 0.08 m/yr
Old Saybrook - All: + 0.01 m/yr
Old Lyme - All*: - 0.25 m/yr
* Only includes portions of town in Zone E
Meigs Point, Hammonasset Beach
Cedar Island
Clinton Beach
Grove Beach
Chapman Point
Harvey'sBeach
Fenwood / Fenwick
Lynde Point
South Cove
North Cove
Ragged Rock Creek Great
Island
Griwold Point to White
Sands Beach
Chaffinch Island
Grass Island
Surf Club
Beach
Webster Point
Minimum End Point Rate: - 2.54 m/yr Maximum End Point Rate: + 2.09 m/yr
Average End Point Rate: -0.09 m/yr
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
3893-60 3905-60 3915-60 3924-60 3935-60 3944-76 3953-76 3962-76 3972-76 3982-76 3991-76 4000-76 4010-76 4021-76 4030-76 4039-76 4048-76 4058-76 4067-76 4076-76 4086-76 4095-76 4104-76 4113-76 4122-76 4131-76 4140-76 4149-76 4158-76 4169-27 4178-27 4187-27 4196-27 4206-27 4215-27 4224-27 4233-27 4242-27 4252-27 4262-27 4271-27 4280-27 4289-27 4298-27 4307-154 4316-154 4325-154 4334-154 4343-154 4352-154 4361-154 4370-154 4379-154 4388-154 4397-154 4407-154 4417-154 4426-154 4438-106 4447-106 4457-106 4466-106 4475-106 4485-106 4494-106 4503-106 4512-106 4521-106 4530-106 4539-106 4548-106 4557-106 4566-106 4575-106 4584-106 4597-106 4606-106 4616-106 4625-106 4634-106 4643-106 4653-106 4664-106 4673-106 4682-106 4692-105 4701-105 4710-105 4719-105 4728-105 4737-105 4747-105 4760-105 4769-105 4778-105 4787-105 4796-105 4805-105 4814-105 4823-105 4833-105 4843-105 4852-105 4861-105 4870-105 4879-105 4888-105 Li
near
Reg
ress
ion
Rate
s (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) Valid Linear Regression Rates: Zone E - Glacial Drift & Beaches
Linear regression rate (Positive) Linear regression rate (Negative)
Guilford*: - 0.39 m/yr (+/- 0.11 m)
Madison: - 0.05 m/yr (+/- 0.03 m)
Clinton: - 0.13 m/yr (+/- 0.03 m)
Westbrook: N/A
Old Saybrook - LIS: N/A
Old Lyme - LIS*: - 0.31 m/yr (+/- 0.09 m)
Old Saybrook - CT River: 0.09 m/yr
(+/- 0.07 m)
Old Lyme - CT River: N/A
Old Saybrook - All: N/A
Old Lyme - All*: - 0.21 m/yr (+/- 0.07)
* Only includes portions of town in Zone E
Meigs Point, Hammonasset Beach
Cedar Island
Clinton Beach
Grove Beach
Chapman Point
Harvey'sBeach
Fenwood / Fenwick
Lynde Point
South Cove
North Cove
Ragged Rock Creek
Great Island
Griwold Point to White
Sands Beach Chaffinch Island
Grass Island Surf
Club Beach
Webster Point
Minimum Linear Regression Rate: - 2.85 m/yr Maximum Linear Regression Rate: + 2.48 m/yr
Average Linear Regression Rate: - 0.08 m/yr
Average Uncertainty (at 86.6% Confidence Interval): +/- 0.02 m/yr
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-200
-100
0
100
200
300
400
4893-105 4902-105 4911-105 4921-105 4930-105 4939-105 4948-45 4958-45 4968-45 4977-45 4987-45 4997-45 5006-45 5015-45 5024-45 5033-45 5042-45 5051-45 5060-45 5070-45 5079-45 5088-45 5097-45 5106-45 5115-45 5124-45 5133-45 5142-45 5151-152 5160-152 5169-152 5178-152 5188-152 5197-152 5207-152 5217-152 5226-152 5235-152 5251-152 5260-152 5269-152 5278-152 5287-152 5296-152 5305-152 5314-152 5323-152 5336-152 5346-152 5358-95 5367-95 5378-95 5387-95 5396-95 5405-95 5414-95 5423-95 5432-95 5441-95 5451-95 5461-95 5472-95 5482-95 5491-95 5502-95 5511-95 5520-95 5529-95 5538-95 5547-95 5556-95 5565-59 5574-59 5583-59 5592-59 5601-59 5610-59 5619-59 5628-59 5642-59 5655-59 5664-59 5673-59 5682-59 5692-59 5702-59 5712-59 5722-59 5731-59 5740-59 5749-59 5758-59 5767-59 5776-59 5786-59 5795-59 5804-59 5813-59 5822-59 5832-59 5841-59 5851-59 5860-59 5870-59 5879-59 5888-59 5897-59 5906-59
Net
Sho
relin
e M
ovem
ent (
met
ers)
Transect Order (west to east)
Long Term (1880 - 2006) Net Shoreline Movement: Zone F - Glacial Drift & Rock
Net Shoreline Movement (Positive) Net Shoreline Movement (Negative)
Old Lyme*: - 6.90 m
New London*: + 19.05 m
Minimum Net Shoreline Movement: - 129.06 m Maximum Net Shoreline Movement: + 316.52 m
Average Net Shoreline Movement: + 5.96 m
* Only includes portions of town in Zone F
Millstone Point
MItchell College
Ocean Beach
State Pier
Black Point / Black Point
Beaches
The Bar
Pattagannsett River
Hatchett Point
Rocky Neck Beach
Goshen Cove
East Lyme: - 1.39 m
Bushy Point Beach / Bluff Point Beach
Jordan Cove
Waterford: - 4.92 m
Pond Point
Millstone
Magonk Point
USCG Academy
Greens Harbor
Electric Boat
US Navy Sub Base
Avery Point
Groton*: + 10.74 m
Venetian Harbor
Mumford Cove
Groton Long Point
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-6
-5.5
-5
-4.5
-4
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
4893-105 4902-105 4911-105 4921-105 4930-105 4939-105 4948-45 4958-45 4968-45 4977-45 4987-45 4997-45 5006-45 5015-45 5024-45 5033-45 5042-45 5051-45 5060-45 5070-45 5079-45 5088-45 5097-45 5106-45 5115-45 5124-45 5133-45 5142-45 5151-152 5160-152 5169-152 5178-152 5188-152 5197-152 5207-152 5217-152 5226-152 5235-152 5251-152 5260-152 5269-152 5278-152 5287-152 5296-152 5305-152 5314-152 5323-152 5336-152 5346-152 5358-95 5367-95 5378-95 5387-95 5396-95 5405-95 5414-95 5423-95 5432-95 5441-95 5451-95 5461-95 5472-95 5482-95 5491-95 5502-95 5511-95 5520-95 5529-95 5538-95 5547-95 5556-95 5565-59 5574-59 5583-59 5592-59 5601-59 5610-59 5619-59 5628-59 5642-59 5655-59 5664-59 5673-59 5682-59 5692-59 5702-59 5712-59 5722-59 5731-59 5740-59 5749-59 5758-59 5767-59 5776-59 5786-59 5795-59 5804-59 5813-59 5822-59 5832-59 5841-59 5851-59 5860-59 5870-59 5879-59 5888-59 5897-59 5906-59
End
Poin
t Rat
e (m
eter
/yea
r)
Transect Order (west to east)
Long Term (1880 - 2006) End Point Rate: Zone F - Glacial Drift & Rock
End Point Rate (Positive) End Point Rate (Negative)
Old Lyme*: - 0.06 m/yr
New London*: + 0.02 m/yr
Minimum End Point Rate: - 5.16 m/yr Maximum End Point Rate: + 0.82 m/yr
Average Net End Point Rate: - 0.03 m/yr
* Only includes portions of town in Zone F
Millstone Point
MItchell College
Ocean Beach
Black Point / Black Point
Beaches
The Bar
Pattagannsett River Hatchett
Point
Rocky Neck Beach
Goshen Cove
East Lyme: - 0.01 m/yr
Bushy Point Beach / Bluff Point Beach
Jordan Cove
Waterford: - 0.08 m/yr
Pond Point
Millstone
Magonk Point Avery Point
Groton*: - 0.02 m/yr
Venetian Harbor
Mumford Cove
Groton Long Point
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-150
-50
50
150
5913-59 5919-59 5925-59 5931-59 5937-59 5943-59 5949-59 5955-59 5961-59 5967-59 5973-59 5981-59 5988-59 5997-59 6003-59 6009-59 6015-59 6021-59 6027-59 6033-137 6039-137 6047-137 6055-137 6061-137 6068-137 6075-137 6081-137 6087-137 6093-137 6101-137 6107-137 6113-137 6119-137 6125-137 6132-137 6138-137 6144-137 6150-137 6156-137 6162-137 6168-137 6176-137 6182-137 6188-137 6195-137 6201-137 6207-137 6213-137 6219-137 6226-137 6232-137 6238-137 6244-137 6251-137 6258-137 6265-137 6271-137 6278-137 6284-137 6290-137 6296-137 6303-137 6309-137 6315-137 6321-137 6329-137 6336-137 6342-137 6348-137 6354-137 6362-137 6370-137 6376-137 6382-137 6390-137 6396-137 6402-137 6408-137 6414-137 6420-137 6427-137 6433-137 6439-137 6446-137 6452-137 6458-137 6464-137 6470-137 6476-137 6482-137 6489-137 6495-137 6501-137 6507-137 6513-137 6519-137 6526-137 6535-137 6542-137 6548-137 6554-137 6560-137 6566-137 6572-137 6579-137 6585-137 6591-137 6597-137 6603-137 6610-137
Net
Sho
relin
e M
ovem
ent (
met
ers)
Transect Order (west to east)
Long Term (1880 - 2006) Net Shoreline Movement: Zone G: Rock & Marshes
Net Shoreline Movement (Positive) Net Shoreline Movement (Negative)
Groton*: + 2.06 m
Minimum Net Shoreline Movement: - 152.39 m Maximum Net Shoreline Movement: + 58.96 m
Average Net Shoreline Movement: -4.53 m
* Only includes portions of town in Zone G
Latimer Point
Edwards Point
Lords Point
Six Penny Island
Noank Dock Morgan Point
Groton Long Point
West Cove
West Shore, Stonington
Harbor
Barn Island
Quaimbog Cove
Ram Point
East Shore,
Mason's Island
MasonPoint
Stonington Point
Wequetequock Cove
Stonington: - 5.89 m
Pawcatuck Point
Pawcatuck River
Palmer Cove
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-1.5
-1
-0.5
0
0.5
1
5913-59 5919-59 5925-59 5931-59 5937-59 5943-59 5949-59 5955-59 5961-59 5967-59 5973-59 5981-59 5988-59 5997-59 6003-59 6009-59 6015-59 6021-59 6027-59 6033-137 6039-137 6047-137 6055-137 6061-137 6068-137 6075-137 6081-137 6087-137 6093-137 6101-137 6107-137 6113-137 6119-137 6125-137 6132-137 6138-137 6144-137 6150-137 6156-137 6162-137 6168-137 6176-137 6182-137 6188-137 6195-137 6201-137 6207-137 6213-137 6219-137 6226-137 6232-137 6238-137 6244-137 6251-137 6258-137 6265-137 6271-137 6278-137 6284-137 6290-137 6296-137 6303-137 6309-137 6315-137 6321-137 6329-137 6336-137 6342-137 6348-137 6354-137 6362-137 6370-137 6376-137 6382-137 6390-137 6396-137 6402-137 6408-137 6414-137 6420-137 6427-137 6433-137 6439-137 6446-137 6452-137 6458-137 6464-137 6470-137 6476-137 6482-137 6489-137 6495-137 6501-137 6507-137 6513-137 6519-137 6526-137 6535-137 6542-137 6548-137 6554-137 6560-137 6566-137 6572-137 6579-137 6585-137 6591-137 6597-137 6603-137 6610-137
End
Poin
t Rat
e (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) End Point Rate: Zone G: Rock & Marshes
End Point Rate (Positive) End Point Rate (Negative)
Groton*: + 0.02 m/yr
Minimum End Point Rate: - 1.23 m/yr Maximum End Point Rate: + 0.48 m/yr
Average End Point Rate: - 0.04 m/yr
* Only includes portions of town in Zone G
Latimer Point
Edwards Point
Lords Point
Six Penny Island
Noank Dock Morgan
Point
Groton Long Point
West Cove
West Shore, Stonington
Harbor
Barn Island Quaimbog
Cove
Ram Point
East Shore,
Mason's Island
MasonPoint
Stonington Point
Wequetequock Cove
Stonington: - 0.05 m/yr
Pawcatuck Point
Pawcatuck River Palmer Cove
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014
-1.5
-1
-0.5
0
0.5
1
5913-59 5919-59 5925-59 5931-59 5937-59 5943-59 5949-59 5955-59 5961-59 5967-59 5973-59 5981-59 5988-59 5997-59 6003-59 6009-59 6015-59 6021-59 6027-59 6033-137 6039-137 6047-137 6055-137 6061-137 6068-137 6075-137 6081-137 6087-137 6093-137 6101-137 6107-137 6113-137 6119-137 6125-137 6132-137 6138-137 6144-137 6150-137 6156-137 6162-137 6168-137 6176-137 6182-137 6188-137 6195-137 6201-137 6207-137 6213-137 6219-137 6226-137 6232-137 6238-137 6244-137 6251-137 6258-137 6265-137 6271-137 6278-137 6284-137 6290-137 6296-137 6303-137 6309-137 6315-137 6321-137 6329-137 6336-137 6342-137 6348-137 6354-137 6362-137 6370-137 6376-137 6382-137 6390-137 6396-137 6402-137 6408-137 6414-137 6420-137 6427-137 6433-137 6439-137 6446-137 6452-137 6458-137 6464-137 6470-137 6476-137 6482-137 6489-137 6495-137 6501-137 6507-137 6513-137 6519-137 6526-137 6535-137 6542-137 6548-137 6554-137 6560-137 6566-137 6572-137 6579-137 6585-137 6591-137 6597-137 6603-137 6610-137
Line
ar R
egre
ssio
n Ra
te (m
eter
s/ye
ar)
Transect Order (west to east)
Long Term (1880 - 2006) Linear Regression Rate: Zone G: Rock & Marshes
Linear Regression Rate (Positive) Linear Regression Rate (Negative)
Groton*: + 0.04 m/yr (+/- 0.03 m)
Minimum Linear Regression Rate: - 1.02 m/yr Maximum Linear Regression Rate: + 0.59 m/yr
Average Linear Regression Rate: N/A
* Only includes portions of town in Zone G
Latimer Point
Edwards Point
Lords Point
Six Penny Island
Noank Dock
Morgan Point
West Cove
West Shore, Stonington
Harbor
Barn Island
Quaimbog Cove
East Shore,
Mason's Island
MasonPoint
Stonington Point
Wequetequock Cove
Stonington: - 0.02 m/yr (+/- 0.01 m)
Pawcatuck River
Palmer Cove
Groton Long Point
Analysis of Shoreline Change in Connecticut: 100 Years of Erosion & Accretion
A cooperative effort between the Connecticut Department of Energy & Environmental Protection, the University of Connecticut Center for Land Use Education and Research and the Connecticut Sea Grant. June, 2014