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Green and Gray Infrastructure: A Spatial framework for considering impacts

The Nature Conservancy-Dow Collaboration Dec 11, 2012

Tim Boucher1, Sheila Walsh1 ,Jorge Brenner1, Rob Griffin2, Greg Guannel2, Anne Guerry2, Jen Molnar1

1. The Nature Conservancy 2. The Natural Capital Project

Losses from Natural Hazards are Increasing

Ecosystems Can Mitigate Losses

Wav

e A

tten

uat

ion

(Gedan et al. 2011)

A framework

Goal: Method for Integrated Hazard Planning

Assess value Value of coastal habitats to

business, community, ecosystems

Evaluate Options Habitat protection, restoration,

gray infrastructure

Develop Strategy Integrate green infrastructure

portfolio into planning

Landcover and Green Infrastructure Scenarios

High Green

Moderate Green

No Green/High Development

Landcover and Green Infrastructure Scenarios

High Green

• Dry Land below 2100 SLR salt line gets restored or allowed to convert to wet/marsh

• Developed below SLR remains*

Landcover and Green Infrastructure Scenarios

Moderate Green

• Limited Development – 2040 projections • Protect or restore wet habitats with

highest expected net benefits

Landcover and Green Infrastructure Scenarios

No Green/High Development

• All Possible Development by 2025

Sea Level Affecting Marshes Model (SLAMM)

Sea Level Affecting Marshes Model (SLAMM)

Within SLAMM, there are six primary processes:

1. Inundation: T he rise of water levels and the salt boundary

2. Erosion: Triggered based on a threshold of maximum fetch and the proximity

of the wetland to estuarine water or open ocean.

3. Overwash: Barrier islands of under 500 meter width are assumed to undergo

overwash during each 25 year time-step due to storms encountered.

4. Saturation: Coastal swamps and fresh marshes can migrate onto adjacent

uplands as a response of the water table to rising sea level close to the coast.

5. Accretion: Upward movement of marshes due to sequestration of sediments

and biogenic production.

6. Salinity: Optional. In a location with defined fresh-water flows, land categories

can migrate based on changes in salinity.

Lidar DEM

Infrastructure

Land Use – Current

Land Use – 2040

Current Land Cover - NLCD

Impervious Surfaces > 20%

Current Land Cover - NWI

Current Land Cover

Current Land Cover - Diked

Current Land Cover

High Green: 1 m SLR– 2100

Moderate Green: 1 m SLR– 2100

Expected Outcomes

Public Benefits • Avoided storms damages • Carbon Sequestration • Recreation & Fisheries

Business Benefits • Hybrid solution offers lowest cost

Conservation Benefits • Demonstrating value of investments in nature

Advancing Science • Advancing ecosystem service science

Acknowledgments

• TNC-Sustainability Science: Sheila Walsh, Jon Fisher, Anthony Rogers, Alex Maas, Jen Molnar

• Dow: Doug Whipple, Daniel Ramirez, John DiMuro, Judy Gunderson

• TNC-Texas: Michael Thompson, Jorge Brenner

• Natural Capital Project: Greg Guannel, Rob Griffin, Joe Faries, Joey Bernhardt, Greg Verutes, Spencer Woods, Jess Silver, Jodie Taft, Anne Guerry

• TNC-Global Marine: Mike Beck, Chris Shepard

• Warren Pinnacle Consulting: Jonathon Clough, Marco Propato, Amy Polaczyk

DOW RESTRICTED - For internal use only