Toward Sustainable Urban Estuaries in the Anthropocene
C.
1University
1
Sommerfield ,
of Delaware,
P.
2
Hoagland ,
2Woods
R.
3
Chant ,
R.
2
Geyer ,
Hole Oceanographic Institution,
Estuaries worldwide have been extensively modified as consequence of
urbanization, industrialization, and marine commerce. In the United
States, shipping channels serving major ports have been deepened to
2-3 times their natural depths, a trend that continues in preparation for
a new generation of post-Panamax megaships. Historical changes in
estuarine morphology have had direct and indirect effects on regional
circulation and sediment movement, leading potentially to far-reaching
cumulative impacts on ecosystems and human uses of estuary
resources. For example, deepened channels and hardened shores may
have reduced the natural capacity of wetlands to attenuate storm
surge, rendering adjacent lands more susceptible to coastal flooding.
1855
-0
5. Ecosystem services identification and initial quantification of
hypothetical losses of carbon sequestration capacities in the
Delaware watershed
Newark
Bay
- 60
0
2.5
5 Miles
1848
2001
Upper
Delaware
Estuary
Port of Philadelphia
Port of NY/NJ
Shipping channel depth (ft)
2. Deployments of oceanographic moorings in Delaware Estuary
2014
- 60
USDT (2010)
45'
50'
The Delaware and Hudson estuaries serve a population
of ~12 million and provide ecosystem goods and services
worth many 10s of billions of dollars per year. We are
exploring the sustainability of these systems in terms of
human modifications to the physical environment,
balanced by the socio-economic and resource needs of
the population.
USACE data
1900
1950
2000
SPECIFIC OBJECTIVES
Year of completion
A certainty of coastal change is the need to accommodate ships of increasing
size. Shipping channels for the Ports of Philadelphia and NY/NJ have been
progressively deepened from 15-20’ in the mid-1800s to current depths of
45-50’. These economically vital ports receive 1000s of ships annually and
continue to grow.
APPROACH
This project focuses on the urbanized Delaware and Hudson estuaries,
home to two major ports in the US mid-Atlantic region—the Port of
Philadelphia and the Port of New York. We are conducting studies of
physical processes to inform numerical models simulating past, present,
and future bathymetric and flow conditions, to determine how these
estuaries respond dynamically to deepening. Similarly, socio-economic
analyses will provide a quantification of ecosystem services through
time. The culmination of the research will be coupled models of
natural-human state trajectories to identify feedbacks between estuary
modifications and to quantify changes in values of altered ecosystem
services.
1. Quantify hydrodynamic and morphologic responses to human modifications of
estuarine bathymetry and shoreline geometry through numerical modeling.
2. Determine the responses of subtidal environments and fringing wetlands to humaninduced changes in the estuarine regime.
3. Characterize the spatial and temporal distributions of the ecosystem service (ES)
values of estuaries and wetlands.
4. Analyze possible future trajectories of the coupled nature-human system, considering
local human-induced perturbations as well as those resulting from sea-level rise and
coastal storms.
Eroding marsh shoreline
Wave gage
Key issues to be addressed:
(1) define the relevant and appropriate nature-human scale for
determining the sustainable management of an urban estuary;
(2) identify a decision framework that permits assessment of socioeconomic values across generations.
State University
4. Exploration of socio-economic models
Channel deepening history
40
4Louisiana
3. Wetland morphodynamics fieldwork in the Delaware Estuary
10
30
University,
G.
1
Parsons
1. Creation of historical digital bathymetric models
-0
20
D.
2
Ralston ,
2013-14 ACCOMPLISHMENTS
Delaware - Hudson Estuary Watershed
We believe that understanding interactions between humans and
modified river-estuarine landscapes is fundamental to sustainability.
In this project we are investigating how human changes in estuarine
morphology affect water and sediment flows, and how shifts in the
physical regime affect sustainability based on a combination of
environmental and socio-economic factors.
1850
3Rutgers
STUDY AREA
INTRODUCTION
50
T.
4
Quirk ,
Instrument
moorings
Wetland
focus area
Wave buoy
Wetland
focus area
Erosion pins
Eroding marsh shoreline
Wave buoy
Estimates of the economic benefits and costs of channel deepening
programs in the Delaware and Hudson estuaries have been
incorporated into environmental assessments to guide policy. Benefits,
defined as opportunities for economic growth or avoided lightering
costs, are weighed against the costs of dredging and spoil disposal. We
plan to broaden the scope and improve the credibility of these costbenefit analyses in several ways.
• Characterize a baseline and at least two alternative scenarios: (i)
deepening the channels to depths that accommodate postPanamax vessels; or (ii) allowing the channels to revert to shallower
depths through natural sedimentation.
• Estimate the values associated with a wider array of ESs (see the
table below), including blue carbon, recreation, avoided drinking
water or industrial cooling water desalination, flooding and erosion
controls, and shellfish bed restorations.
• Supplement extant ES values for use in benefit transfers with our
own studies for which such transfers may be problematic, such as
travel cost studies of recreation and hedonic studies of coastal risks.
HUMAN USE (BENEFIT)
Transport
Drinking Water
ECOSYSTEM SERVICES
Channel depth/width
Water supply
ECOSYSTEM SERVICES FUNCTION (DESCRIPTION)
Provides a low-cost mode for the shipment of economic goods
Provides a source of low-salinity, low-sediment freshwater
Physical, chemical, or biological processes flush, dilute,
Waste Disposal
Waste sink
assimilate, breakdown, or sequester anthropogenic effluents
Above- and underground biomass in wetlands, intertidal, and
Carbon Sequestration Carbon storage
submerged lands stores fixed carbon
Provide water quantity/quality for industrial processes and
Cooling Water
Water supply
power plants
Beaches, open water, and wetlands provide both a physical
Recreation
Places to work or play
environment for recreation and habitat for fauna and flora
valued by humans
Shoreline areas that are
Wetlands and beach-dune systems serve as physical barriers to
Storm Protection
protected from or resilient to floodwater inundation and land erosion; wetlands absorb excess
flooding and erosion
stormwater
Increased wetland area provides nursery and refuge habitat for
Commercial Fishing
Fish stocks
variety of aquatic species, preserving biodiversity
Spoil Recovery or
Amending beach/intertidal/wetland area, provide raw materials
Raw materials
Deposition
for construction
Ecosystem robustness/
Biological complexity contributes to robust ecosystems.
Biodiversity
adaptability; genetic resources Biological material is used for medical and research purposes
Aesthetic, Cultural, Artistic,
Supplies of clean water, undisturbed landscapes, ways of life,
Aesthetic/Cultural
Educational, Spiritual, and
spiritual connections to undeveloped land and native species
Historic
have local importance
Non-use
(All of the above)
Passive values attributed to the components of the estuary
This research is supported by NSF Coastal SEES Grant No. 1325136. We thank the following
graduate students for assistance: Ed Carr (UD/CEOE); Yossi Shirazi (UD/CEOE); Conor McDowell
(UD/CEOE); Katie Pajenowski (UD/CEOE); Kelly Heber (MIT/DUSP).