© 2018 Allan Kapoor

Bay Adapt: A Coastal Morphology and Land Use Typology to Inform Adaptive Infrastructure Decisions

San Francisco Bay Area

OVERVIEW

Bay Adapt is a geospatial analysis of the San Francisco Bay shoreline to inform sea level rise adaptation strategy decisions at the regional and local level. 

The results of this project can be used by planners in coastal communities throughout the Bay Area to assess which physical adaptation strategies are most likely to be applicable to their shorelines.

The project divided the entire 660 mile coastline into 100-ft segments and classified each into typologies based on edge condition, slope, exposure to wave action, and adjacent land use:

For each shoreline type, I rated the likely applicability of 29 different physical adaptation strategies, based on NYC Planning's 2013 Urban Waterfront Adaptive Strategies report.

Below is an example matrix summarizing likely applicability of in-water strategies to the San Francisco Bay's shoreline types:

REGIONAL RESULTS

Using different methods and datasets (see methodology below), I produced a map of the entire San Francisco Bay for each category within the typology:

I then combined the categories to assign a coastal morphology type and land use type for each 100-ft stretch of shoreline. The trends for the entire shoreline are below:

PROJECT

Master's Final Project, UC Berkeley

DURATION

12 months

SKILLS

Concept Model Development

Adaptive Infrastructure Decisions

Coastal Morphology Analysis

Regional Land Use Analysis

TOOLS

ArcGIS Model Builder

Adobe Illustrator

Adobe InDesign

LOCAL RESULTS

The value of the analysis is not just showing bay-wide trends. The typology also enables coastal planners & designers to quickly determine potential adaptation strategies for specific locations by comparing a shoreline's type with the ratings of likely applicability.

Below is an example of how this process can be applied to the Maclaughlin Eastshore State Park near the Bay Bridge in Emeryville:

METHODOLOGY - COASTAL MORPHOLOGY

Edge condition, exposure to wave action, and mean inland slope were combined into a coastal morphology typology, which can be used to predict the applicability of upland, shoreline, and in-water adaptation strategies.

EXPOSURE TO WAVE ACTION

 

Data Source

FEMA - Flood Insurance Rate Maps

 

Method Summary

Combined existing flood insurance rate maps (FIRMS) for the entire Bay Area with the preliminary FIRM for San Francisco County and then tagged all shoreline segments as “exposed to wave action” if they were within 150 ft of a Coastal V Zone or a Coastal VE Zone.

 

Category Definitions:

 

Exposed

Coastal V Zones

Coastal VE Zones

 

Sheltered

Zone X

Zone A

Zone B

Zone C

Zone D

EDGE TYPE

 

Data Source

SFEI - SF Bay Shoreline Inventory

 

Method Summary

Separated line segments in the existing shoreline inventory polyline shapefile into simplified categories, and restricted analysis to shoreline segments tagged as “first line of defense” or “wetland on bay shore”.

 

 

Category Definitions:

 

Natural Edges   

Natural Shorelines

Wetland Modified Edges (Soft)

Unfortified Berms

Unfortified Engineered Levees

Modified Edges (Hardened)

Floodwalls

Fortified Berms

Fortified Engineered Levee

Shoreline Protection Structures     Transportation Structures

ADJACENT TOPOGRAPHY

 

Data Source

USGS - 1/3 arc-sec DEM

 

Method Summary

Used a slope and focal statistics analysis tocalculated mean slope within 600 ft of the center of each shoreline segment. Determined category brackets by comparing mean slopes to observed geomorphology in several locations.

 

 

Category Definitions:

 

Gentle Slopes

Mean slope within 600 ft is <0.55%

 

Medium Slopes

Mean slope within 600 ft is between 0.55% and 3.5%

 

Steep Slopes

Mean slope within 600 ft is >3.5%

METHODOLOGY - LAND TYPOLOGY

Data Source

ABAG - 2005 Land Use Inventory US Census - ACS 2016 5-Year Estimates (dwelling units)

Method Summary

Reclassified USGS land use codes into categories. Split residential/commercial/mixed-use land into density categories by dividing the number of dwelling units by acres of residential land for each block group and applying that to the existing land use inventory. Finally, using a focal statistics analysis, calculate the most predominant land use within 1/4 mile of each shoreline segment.

 

Category Definitions:

1-2 Family Residential

Residential land in block groups with a density of 0-10 du/acre

 

Low/Mid Rise Residential/Commercial/Mixed-Use

Residential, commercial, and mixed-use land in block groups with a density of 10-35 du/acre

 

High Rise Residential Commercial/Mixed-Use

Residential, commercial, and mixed-use land in block groups with a density greater than 35 du/acre

 

Major Infrastructure

Airports, maritime ports, power facilities, waterwater and water supply facilities, landfills and recycling centers, hospitals with trauma centers, railways and related facilities, highways and related facilities

Open Space

Urban open space, agriculture, rangeland, wetlands, forests, sparse vegetation, military open space, commercial outdoor recreation

Industrial

Light industrial, heavy industrial, ind/com mixed-use