1
KTAN members are concerned with developing strategies that balance shoreline development and preservaon of ecosystem services such as beach accessibility. Future scenario analysis using ENVISION integrates stakeholder-driven strategies, physical processes data, and climate change impact informaon in an innovave and iterave way, and allows for the analysis of site-specific adaptaon policy costs and benefits. Community engagement helps to fulfill KTAN members’ requests for addional opportunies to engage with OSU researchers and outreach specialists and ensures that model results are “legimate” and “salient” (Cash, et al., 2003). Connue to refine the probabilisc total water level model (Serafin and Ruggiero, 2014) that includes climate variability into ENVISION via Monte Carlo simulaons. Connue to determine the economic costs and benefits of specific adaptaon strategies, and idenfy “preferred” strategies (those that best support the community’s goals) to model within ENVISION. Present informaon about the final “preferred” strategies to the general public to inform future implementaon efforts. 1.Build coastal Knowledge to Acon Networks (KTAN). 2. Develop methodologies to project evolving coastal flooding and erosion based on adaptaon strategy and climate scenarios. 3. Develop the informaon and tools to help county stakeholders assess impacts and vulnerability, and implement beneficial strategies. Methods Sea level rise (SLR), increasing storminess, and growing development pressures are intensifying coastal vulnerability on the US West Coast, including in Tillamook County, Oregon. Many beaches have not fully recovered from the major El Niño of the late 1990s. Under Oregon Statewide Planning Goal 18, only some communies and residents may construct expensive hard engineering protecve structures. Local decision-makers and stakeholder groups oſten lack the informaon and tools to reduce their vulnerability and increase the community’s adapve capacity or “the ability to prepare, adjust, and/or respond to changes in advance” (Gallopin, 2006). Three ways to develop adapve capacity in Tillamook County: Figures 9 and 10: Number of buildings impacted by flooding under low (leſt) and high (right) impact climate scenarios from 2010 to 2100 (county-wide). Status Quo Hold The Line Policy Narrave Legend ReAlign Laissez-Faire Buildings Impacted by Flooding in the Low Impact Climate Scenario How will coastal flood hazards impact buildings in the future? Buildings Impacted by Flooding in the High Impact Climate Scenario Figure 7: One example of projected maximum yearly TWL events in a medium impact climate scenario. Landscape Data and Change Models Projected Populaon Growth in Tillamook County Land Use/ Land Cover Zoning Structures Topography Projected Number of Buildings within Urban Growth Boundaries (UGBs) Figure 5: County-wide populaon growth. (OOEA, 2013). Figure 6: Buildings constructed within UGBs in a Status Quo policy scenario under a medium impact climate scenario. Figure 8: One example of projected maximum yearly extent of erosion in a medium impact climate scenario. The example only represents event based potenal foredune erosion. Sea Level Rise (SLR) Scenarios 2010—2100 Wave Height Distribuon by 2100 wave heights increase wave heights decrease Climate Impact Scenarios Flooding and Erosion Models 4 4.5 5 5.5 6 6.5 7 2010 2030 2050 2070 2090 Maximum Yearly TWL Event (m) Maximum Yearly TWL Event (m) Maximum Yearly TWL Event (m) 3 5 7 9 11 13 15 17 2010 2030 2050 2070 2090 Maximum Yearly Extent of Erosion (m) Maximum Yearly Extent of Erosion (m) Maximum Yearly Extent of Erosion (m) Yearly Maximum Extent of Erosion on Example Transect ENVISION Modeling Components Example Results ACKNOWLEDGMENTS: This work is supported by the Coastal and Ocean Climate Applicaons (COCA) program of the U.S. Department of Commerce's Naonal Oceanic and Atmospheric Administraon (NOAA) under NOAA Grant NA12OAR4310109 and the Pacific Northwest Climate Impacts Research Consorum (CIRC) under NOAA Grant NA10OAR4310218. Lead author Lipiec ([email protected]) was also supported by Oregon State University’s Provost Fellowship at the me of this presentaon. Status Quo Connuaon of present day policies. Hold The Line Policies or decisions are implemented that involve resisng environmental change (e.g. building or raising flood defenses, building or strengthening shoreline armor, nourishing beaches) in order to preserve exisng infrastructure and human acvies (e.g. beach access). ReAlign Policies or decisions are implemented that involve changing human acvies to suit the changing environment (e.g. relocaon of infrastructure and/or people, changing land use or livelihoods). Laissez-Faire Current policies (state and county) are relaxed such that defense of exisng homes, infrastructure, and new development all trump the protecon of coastal resources, public rights, recreaonal use, beach access, and sce- nic views. Policy Scenario Narraves 2040 Hold The Line 2010 Exisng BPS New BPS necessary Figures 11 and 12: Locaon of Rockaway Beach in Tillamook County, Oregon Figures 13- 15: BPS constructed in a high impact climate scenario under Hold the Line policy narrave in the Rockaway Beach lioral subcell. To project future coastal hazards under a variety of adaptaon strategies, OSU researchers needed to develop quantave methods of modeling qualitave policies. To do so, we used the following Model Assumpons: Annually, BPS construcon is limited to 30% of qualified properes to account for permit processing mes, resource scarcity, etc. BPS are constructed under a specific set of instances: The beach is dune-backed AND The land behind the dune is developed AND The dune toe is impacted by the maximum daily TWL >25% of the year OR the building(s) is impacted by erosion >5x in 10 years. Locaons of BPS over me in the Rockaway Beach Lioral Subcell in a High Impact Climate Scenario 2100 DOGAMI 2060 Example Conclusions: Under the Hold The Line policy scenario, most BPS are constructed between 2010 - 2040 than between the years 2040 and 2060. Over 60% of the Rockaway Beach lioral subcell coast needs protecon by BPS in 2100, in comparison to Tillamook County’s overall need of ~10%. Example Conclusions: Different policy narraves have different development paerns and adaptaon strategies, influencing the number of buildings impacted by flooding with the fewest hazard impacts occurring by 2100 in the ReAlign policy narrave (green line) for both low and high climate impact scenarios. Flooding impacts are variable from year to year due to irregular climate events (damaging storms), however, unique trends are evident for all four policy narraves. When will homeowners need backshore protecon structures (BPS) to protect their property? Credit: K. Serafin FLOODING EROSION Low Impact: The low climate impact scenario uses low-end esmates of regional sea level rise (SLR) of ~11cm by 2100 developed within the Naonal Research Council’s (NRC) 2012 SLR report. Medium Impact: The medium climate impact scenario uses NRC (2012) derived mean esmates of regional SLR of ~61cm by 2100. High Impact: The high climate impact scenario uses NRC (2012) derived high-end esmates of regional SLR, ~1.42m by 2100. Significant wave heights for all three climate impact scenarios are based on wave height distribuons developed from the variability of stascally and dynamically downscaled projected global climate model (GCM) esmates for the Northeast Pacific Ocean (Hemer et al., 2013; Wang et al., 2014). For more details, see Poster P51—Serafin et.al CO-DEVELOPING ADAPTIVE CAPACITY IN THE FACE OF EVOLVING CLIMATE CHANGE-INDUCED COASTAL VULNERABILITY E. LIPIEC 1 , P. RUGGIERO 1 , K. SERAFIN 1 , A.K. MILLS 2 , J.P. BOLTE 2 , P.E. CORCORAN 1,3 , J. STEVENSON 1 , D.H. LACH 4 , C.M. ZANOCCO 4 1.COLLEGE OF EARTH, OCEAN, AND ATMOSPHERIC SCIENCES, OREGON STATE UNIVERSITY, CORVALLIS, OR 2.. BIOLOGICAL AND ECOLOGICAL ENGINEERING, OREGON STATE UNIVERSITY, CORVALLIS, OR 3. OREGON STATE EXTENSION SERVICE, CLATSOP COUNTY, OR 4. SCHOOL OF PUBLIC POLICY, OREGON STATE UNIVERSITY, CORVALLIS, OR Background and Goals DOGAMI Kriebel and Dean, 1993 REFERENCES Bruun, P. (1962) Sea-level rise as a cause of shore erosion. Proceed- ings of the American Society of Civil Engineers. Journals of the Water- ways and Harbors Division, 88, 117-130. Cash, D. W., Clark, W. C., Alcock, F., Dickson, N. M., Eckley, N., Guston, D. H., . . . Mitchell, R. B. (2003). Knowledge systems for sustainable development. Proceedings of the Naonal Academy of Sci- ences, 8086-8091. Hemer, M. A., Fan, Y., Mori, N., Semedo, A., and X.L. Wang (2013), Projected changes in wave climate from a mul-model ensem- ble. Nature Climate Change, 3(5), 471-476. Kriebel, D.L. and R.G. Dean. (1993) Convoluon method for me- dependent beach-profile response, Journal of Waterway, Port, and Coastal Engineering, 119, 204-226. Naonal Research Council (2012), Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future. Com- miee on Sea Level Rise in California, Oregon, and Washington: Board on Earth Sciences and Resources; Ocean Studies Board; Division on Earth and Life Studies. Oregon Office of Economic Analysis (OOEA) (2013), Long Term County Populaon Forecast. Ruggiero, P., Komar, P.D., McDougal, W.G., Marra, J.J., and R.A. Beach (2001) Wave runup, extreme water levels and erosion of prop- eres backing beaches. Journal of Coastal Research, 407-419. Serafin, K.A., and P. Ruggiero (2014), Simulang extreme total wa- ter levels using a me-dependent, extreme value approach. Journal of Geophysical Research: Oceans, 119, doi:10.1002/2014JC010093. Stockdon, H. F., Holman, R. A., Howd, P. A., and Sallenger, A. H. (2006), Empirical parameterizaon of setup, swash, and runup, Coast. Eng., 53, 573–588. Wang, X. L., Feng, Y., and V. Swail (2014), Changes in global ocean wave heights as projected using mul-model CMIP5 simulaons. Geo- physical Research Leers. 1. Engaging the Community Creaon of a KTAN: ~20 community members, including individuals from varying departments of state, county, and local government, non-profits, private cizens, Oregon State University (OSU) researchers, and outreach specialists. Formal engagements and as needed informal discussions to develop and assess narraves and scenarios. Presentaon of results for review and comment to the broader community. OSU researchers and outreach specialists work closely with other members of the KTAN to: Idenfy and characterize desired endpoints for the community, Arculate policy narraves to reach these community goals, and Iteravely review and assess the results of future scenario analysis (described below). P. Corcoran Figure 4: Future wave climate scenarios for Oregon. Figure 3: Regional SLR scenarios for Oregon. x b = surf zone width h b = breaking wave depth β f = foreshore beach slope D = vercal elevaon of the dune crest above the dune toe ℎ = + 2. Envisioning Future Scenarios The spaally explicit, mul-paradigm modeling framework ENVISION is ulized to create and analyze plausible future scenarios. Figure 1: Iterave stakeholder-driven process of developing and evaluang future scenarios. Figure 2: Envision modeling components. 3. Incorporang Climate Change Uncertainty Climate change impact scenarios were developed using recommendaons from the Naonal Research Council for SLR on the West Coast and downscaled projected esmates for Northeast Pacific significant wave heights (Hemer et al., 2013; Wang et al., 2014). See CLIMATE IMPACT SCENARIOS. Future scenarios analysis allows for the assessment of alternave coastal management opons under various populaon and development trends, coastal and landscape processes and feedbacks, and climate change impacts. Yearly Maximum Total Water Level (TWL) on Example Transect Take Home Messages Next Steps 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2010 2030 2050 2070 2090 Percent of Coast With BPS Construction Percent of Coast with BPS Construcon: Rockaway Beach Lioral Subcell vs. County-Wide Figure 16: Percent of shoreline with BPS constructed in a high impact climate scenario under Hold the Line policy narrave in the Rockaway Beach lioral subcell and county-wide. Rockaway Beach Lioral Subcell County-Wide = + ℎ − /2 () = + + + Ruggiero, 2001; Serafin and Ruggiero, 2014, and Stockdon et al., 2006 MSL = mean sea level η A = astronomical de η NTR = non-dal residual (e.g., storm surge, El Nino effects, etc.) R = runup, a wave-induced water level (a funcon of beach slope, wave height, and wave length) CCR SB = long-term (interannual to decadal) coastal change rate associated with sediment budget factors not influenced by climate change (e.g., changes in sediment supply due to engineering structures) CCR SLR = coastal change rate associated with SLR (Bruun, 1962) T = me period of interest

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Page 1: 90% Background and Goals CO DEVELOPING ADAPTIVE …envision.bioe.orst.edu/StudyAreas/Tillamook/... · Many beaches have not fully recovered from the major El Niño of the late 1990s

● KTAN members are concerned with developing strategies that balance shoreline development and preservation of ecosystem services such as

beach accessibility.

Future scenario analysis using ENVISION integrates stakeholder-driven strategies, physical processes data, and climate change impact

information in an innovative and iterative way, and allows for the analysis of site-specific adaptation policy costs and benefits.

Community engagement helps to fulfill KTAN members’ requests for additional opportunities to engage with OSU researchers and outreach

specialists and ensures that model results are “legitimate” and “salient” (Cash, et al., 2003).

Continue to refine the probabilistic total water level model (Serafin and Ruggiero, 2014) that includes climate variability into ENVISION via Monte

Carlo simulations.

● Continue to determine the economic costs and benefits of specific adaptation strategies, and identify “preferred” strategies (those that best

support the community’s goals) to model within ENVISION.

● Present information about the final “preferred” strategies to the general public to inform future implementation efforts.

1.Build coastal Knowledge to Action Networks (KTAN).

2. Develop methodologies to project evolving coastal flooding and erosion based on adaptation strategy and climate scenarios.

3. Develop the information and tools to help county stakeholders assess impacts and vulnerability, and implement beneficial strategies.

Methods

● Sea level rise (SLR), increasing storminess, and growing development

pressures are intensifying coastal vulnerability on the US West Coast,

including in Tillamook County, Oregon.

● Many beaches have not fully recovered from the major El Niño of the

late 1990s.

● Under Oregon Statewide Planning Goal 18,

only some communities and residents may

construct expensive hard engineering

protective structures.

● Local decision-makers and stakeholder groups often lack the

information and tools to reduce their vulnerability and increase the community’s

adaptive capacity or “the ability to prepare, adjust, and/or respond to changes in

advance” (Gallopin, 2006).

Three ways to develop adaptive capacity in Tillamook County:

Figures 9 and 10: Number of buildings impacted by

flooding under low (left) and high (right) impact

climate scenarios from 2010 to 2100 (county-wide).

Status Quo

Hold The Line

Policy Narrative Legend

ReAlign

Laissez-Faire

Buildings Impacted by Flooding in the

Low Impact Climate Scenario

How will coastal flood hazards impact buildings in the future?

Buildings Impacted by Flooding in the

High Impact Climate Scenario

Figure 7: One example of projected

maximum yearly TWL events in a

medium impact climate scenario.

Landscape Data and Change Models

Projected Population Growth in Tillamook County

Land Use/

Land Cover

Zoning

Structures

Topography

Projected Number of Buildings within Urban Growth Boundaries (UGBs)

Figure 5: County-wide population growth. (OOEA, 2013). Figure 6: Buildings constructed within UGBs in a Status Quo policy scenario under a medium

impact climate scenario.

Figure 8: One example of projected

maximum yearly extent of erosion in

a medium impact climate scenario.

The example only represents event

based potential foredune erosion.

Sea Level Rise (SLR) Scenarios 2010—2100 Wave Height Distribution by 2100

wave heights

increase

wave heights

decrease

Climate Impact Scenarios

Flooding and Erosion Models

4

4.5

5

5.5

6

6.5

7

2010 2030 2050 2070 2090

Max

imu

m Y

ear

ly T

WL

Eve

nt

(m)

Max

imu

m Y

ear

ly T

WL

Eve

nt

(m)

Max

imu

m Y

ear

ly T

WL

Eve

nt

(m)

3

5

7

9

11

13

15

17

2010 2030 2050 2070 2090Max

imu

m Y

ear

ly E

xte

nt

of

Ero

sio

n (

m)

Max

imu

m Y

ear

ly E

xte

nt

of

Ero

sio

n (

m)

Max

imu

m Y

ear

ly E

xte

nt

of

Ero

sio

n (

m)

Yearly Maximum Extent of Erosion on Example Transect

ENVISION Modeling Components Example Results

ACKNOWLEDGMENTS: This work is supported by the Coastal and Ocean Climate Applications (COCA) program of the U.S.

Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) under NOAA Grant NA12OAR4310109 and

the Pacific Northwest Climate Impacts Research Consortium (CIRC) under NOAA Grant NA10OAR4310218. Lead author Lipiec

([email protected]) was also supported by Oregon State University’s Provost Fellowship at the time of this presentation.

Status Quo

Continuation of present day policies.

Hold The Line

Policies or decisions are implemented that involve resisting environmental change (e.g. building or raising flood defenses, building or strengthening shoreline armor, nourishing beaches) in order to preserve existing infrastructure and human activities (e.g. beach access).

ReAlign Policies or decisions are implemented that involve changing human activities to suit the changing environment (e.g. relocation of infrastructure and/or people, changing land use or livelihoods).

Laissez-Faire Current policies (state and county) are relaxed such that defense of existing homes, infrastructure, and new development all trump the protection of coastal resources, public rights, recreational use, beach access, and sce-nic views.

Policy Scenario Narratives

2040

Ho

ld T

he

Lin

e

2010

Existing BPS

New BPS

necessary

Figures 11 and 12:

Location of Rockaway

Beach in Tillamook

County, Oregon

Figures 13- 15:

BPS constructed in a

high impact climate

scenario under Hold

the Line policy

narrative in the

Rockaway Beach

littoral subcell.

To project future coastal hazards under a variety of adaptation strategies, OSU researchers

needed to develop quantitative methods of modeling qualitative policies. To do so, we used

the following Model Assumptions:

● Annually, BPS construction is limited to 30% of qualified properties to account for

permit processing times, resource scarcity, etc.

● BPS are constructed under a specific set of instances:

● The beach is dune-backed AND

● The land behind the dune is developed AND

● The dune toe is impacted by the maximum daily TWL >25% of the year OR the

building(s) is impacted by erosion >5x in 10 years.

Locations of BPS over time in the Rockaway Beach Littoral Subcell in a High Impact Climate Scenario

2100

DOGAMI

2060

Example Conclusions:

● Under the Hold The Line policy scenario, most BPS are constructed between 2010 - 2040 than between the years 2040 and 2060.

● Over 60% of the Rockaway Beach littoral subcell coast needs protection by BPS in 2100, in comparison to Tillamook County’s overall need of ~10%.

Example Conclusions:

● Different policy narratives have different development patterns and adaptation strategies, influencing the number of buildings impacted by flooding with the

fewest hazard impacts occurring by 2100 in the ReAlign policy narrative (green line) for both low and high climate impact scenarios.

● Flooding impacts are variable from year to year due to irregular climate events (damaging storms), however, unique trends are evident for all four policy

narratives.

When will homeowners need backshore protection structures (BPS) to protect their property?

Credit: K. Serafin

FLO

OD

ING

ER

OSI

ON

Low Impact: The low climate impact scenario uses low-end estimates of regional sea

level rise (SLR) of ~11cm by 2100 developed within the National Research Council’s

(NRC) 2012 SLR report.

Medium Impact: The medium climate impact scenario uses NRC (2012) derived mean

estimates of regional SLR of ~61cm by 2100.

High Impact: The high climate impact scenario uses NRC (2012) derived high-end

estimates of regional SLR, ~1.42m by 2100.

Significant wave heights for all three climate impact scenarios are based on wave

height distributions developed from the variability of statistically and dynamically

downscaled projected global climate model (GCM) estimates for the Northeast

Pacific Ocean (Hemer et al., 2013; Wang et al., 2014).

For more details, see Poster P51—Serafin et.al

CO-DEVELOPING ADAPTIVE CAPACITY IN THE FACE OF EVOLVING CLIMATE CHANGE-INDUCED COASTAL VULNERABILITY E. LIPIEC1, P. RUGGIERO1, K. SERAFIN1, A.K. MILLS2, J.P. BOLTE2, P.E. CORCORAN1,3, J. STEVENSON1, D.H. LACH4, C.M. ZANOCCO4

1.COLLEGE OF EARTH, OCEAN, AND ATMOSPHERIC SCIENCES, OREGON STATE UNIVERSITY, CORVALLIS, OR

2.. BIOLOGICAL AND ECOLOGICAL ENGINEERING, OREGON STATE UNIVERSITY, CORVALLIS, OR

3. OREGON STATE EXTENSION SERVICE, CLATSOP COUNTY, OR

4. SCHOOL OF PUBLIC POLICY, OREGON STATE UNIVERSITY, CORVALLIS, OR

Background and Goals

DOGAMI

Kriebel and Dean, 1993

REFERENCES

Bruun, P. (1962) Sea-level rise as a cause of shore erosion. Proceed-

ings of the American Society of Civil Engineers. Journals of the Water-ways and Harbors Division, 88, 117-130.

Cash, D. W., Clark, W. C., Alcock, F., Dickson, N. M., Eckley, N., Guston, D. H., . . . Mitchell, R. B. (2003). Knowledge systems for

sustainable development. Proceedings of the National Academy of Sci-ences, 8086-8091.

Hemer, M. A., Fan, Y., Mori, N., Semedo, A., and X.L. Wang (2013), Projected changes in wave climate from a multi-model ensem-

ble. Nature Climate Change, 3(5), 471-476.

Kriebel, D.L. and R.G. Dean. (1993) Convolution method for time-

dependent beach-profile response, Journal of Waterway, Port, and Coastal Engineering, 119, 204-226.

National Research Council (2012), Sea-Level Rise for the Coasts of

California, Oregon, and Washington: Past, Present, and Future. Com-mittee on Sea Level Rise in California, Oregon, and Washington: Board on Earth Sciences and Resources; Ocean Studies Board; Division on Earth and Life Studies.

Oregon Office of Economic Analysis (OOEA) (2013), Long Term

County Population Forecast.

Ruggiero, P., Komar, P.D., McDougal, W.G., Marra, J.J., and R.A.

Beach (2001) Wave runup, extreme water levels and erosion of prop-

erties backing beaches. Journal of Coastal Research, 407-419.

Serafin, K.A., and P. Ruggiero (2014), Simulating extreme total wa-

ter levels using a time-dependent, extreme value approach. Journal of Geophysical Research: Oceans, 119, doi:10.1002/2014JC010093.

Stockdon, H. F., Holman, R. A., Howd, P. A., and Sallenger, A. H. (2006), Empirical parameterization of setup, swash, and runup,

Coast. Eng., 53, 573–588.

Wang, X. L., Feng, Y., and V. Swail (2014), Changes in global ocean

wave heights as projected using multi-model CMIP5 simulations. Geo-physical Research Letters.

1. Engaging the Community Creation of a KTAN: ~20 community members, including

individuals from varying departments of state, county, and local government, non-profits, private citizens, Oregon State University (OSU) researchers, and outreach specialists.

Formal engagements and as needed informal discussions to develop and assess narratives and scenarios.

Presentation of results for review and comment to the broader community.

OSU researchers and outreach specialists work closely with other members of the KTAN to:

Identify and characterize desired endpoints for the community,

Articulate policy narratives to reach these community goals, and

Iteratively review and assess the results of future scenario analysis (described below).

P. Corcoran

Figure 4: Future wave climate scenarios for Oregon. Figure 3: Regional SLR scenarios for Oregon.

xb = surf zone width

hb = breaking wave depth

βf = foreshore beach slope

D = vertical elevation of the

dune crest above the dune toe

𝐶ℎ𝑟𝑜𝑛𝑖𝑐 𝐸𝑟𝑜𝑠𝑖𝑜𝑛 = 𝐶𝐶𝑅𝑆𝐵 + 𝐶𝐶𝑅𝑆𝐿𝑅 ∗ 𝑇

2. Envisioning Future Scenarios The spatially explicit,

multi-paradigm modeling framework ENVISION is utilized to create and analyze plausible future scenarios.

Figure 1: Iterative stakeholder-driven process of

developing and evaluating future scenarios.

Figure 2: Envision modeling components.

3. Incorporating Climate Change Uncertainty

Climate change impact scenarios were developed using recommendations from the

National Research Council for SLR on the West Coast and downscaled projected

estimates for Northeast Pacific significant wave heights (Hemer et al., 2013; Wang et al.,

2014). See CLIMATE IMPACT SCENARIOS.

● Future scenarios

analysis allows for the

assessment of alternative coastal management options under various population and development trends, coastal and landscape processes and feedbacks, and climate change impacts.

Yearly Maximum Total Water Level (TWL) on Example Transect

Take Home Messages

Next Steps

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2010 2030 2050 2070 2090

Pe

rce

nt

of

Co

ast

Wit

h B

PS

Co

nst

ruct

ion

Percent of Coast with BPS Construction:

Rockaway Beach Littoral Subcell vs. County-Wide

Figure 16: Percent of shoreline with BPS constructed in a high impact

climate scenario under Hold the Line policy narrative in the Rockaway Beach

littoral subcell and county-wide.

Rockaway Beach Littoral

Subcell

County-Wide

𝐸𝑣𝑒𝑛𝑡 𝐵𝑎𝑠𝑒𝑑 𝑃𝑜𝑡𝑒𝑛𝑡𝑖𝑎𝑙 𝐹𝑜𝑟𝑒𝑑𝑢𝑛𝑒 𝐸𝑟𝑜𝑠𝑖𝑜𝑛

=

𝑇𝑊𝐿 𝑥𝑏 −ℎ𝑏

𝑡𝑎𝑛𝛽𝑓

𝐷 + ℎ𝑏 − 𝑇𝑊𝐿/2

𝑇𝑜𝑡𝑎𝑙 𝑊𝑎𝑡𝑒𝑟 𝐿𝑒𝑣𝑒𝑙 (𝑇𝑊𝐿) = 𝑀𝑆𝐿 + 𝜂𝐴 + 𝜂𝑁𝑇𝑅 + 𝑅

Ruggiero, 2001; Serafin and Ruggiero, 2014, and Stockdon et al., 2006

MSL = mean sea level

ηA = astronomical tide

ηNTR = non-tidal residual

(e.g., storm surge, El Nino effects, etc.)

R = runup, a wave-induced

water level (a function of

beach slope, wave height,

and wave length)

CCRSB = long-term (interannual to decadal) coastal change rate associated with sediment budget factors not

influenced by climate change (e.g., changes in sediment supply due to engineering structures)

CCRSLR = coastal change rate associated with SLR (Bruun, 1962)

T = time period of interest