Communicating Chesapeake Bay Water Quality Issues Using 3D and Temporal GIS

John WolfCapstone Project Proposal

September 21, 2011 1

Presentation Overview

• Background– Chesapeake Bay overview– Total Maximum Daily Load (TMDL) and the Bay restoration effort– Existing communication challenges -- visualizing Bay Health and

Factors Affecting Bay Health• Goals and Objectives of Project• Proposed Approach and Methods

– Existing data and models to be leveraged– Analysis/data manipulation

• Project Timeline

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Chesapeake Bay• Largest of 130 estuaries in United States• Approximately 200 miles long• Average depth is 21 feet• Produces about 500 million lbs of seafood each year

What is an Estuary?• Partially enclosed body of water where fresh water from

streams and rivers mixes with salt water from the ocean• Among the most productive environments on Earth• Variety of habitats that support diverse plant and animal

communities

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Background Goals and Objectives Approach/Methods Timeline

Background Goals and Objectives Approach/Methods Timeline

Chesapeake Bay Watershed• 64,000 square mile

watershed – six states and D.C.

• 17+ Million people• 150 major rivers and

streams – Susquehanna contributes about 50% of all freshwater

• Land-to-water ratio (14:1) makes the Bay particularly susceptible to what happens on the land

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Chesapeake Bay Total Maximum Daily Load (TMDL)

• TMDL is a “pollution diet” for streams, creeks, and rivers• Required by the Clean Water Act and administered by

the US Environmental protection Agency (EPA) for waters that don’t meet standards

• Defines amount of pollution a water body can handle and still be healthy

• Bay and tributaries are “overweight” with excess nitrogen, phosphorus and sediment, which …

• Fuel algae blooms that impact water quality (low dissolved oxygen, water clarity) and aquatic life

Largest and most complex TMDL in the U.S.5

Background Goals and Objectives Approach/Methods Timeline

EcologicalEndpoints

WaterQualityGoals

Nutrient LoadReduction

Goals

PracticeImplementation

Goals

Watershed Implementation Plans and State 2-Year Milestones for practice implementation

Adopted from National Research Council 2011

Chesapeake Bay Total Maximum Daily Load (TMDL) for nitrogen, phosphorus, and sediment (Clean Water Act)

Restoration of underwater grasses, fisheries, benthic communities, and faunal diversity

Meet Bay water quality criteria for dissolved oxygen, water clarity and chlorophyll-a concentrations

Overview of Chesapeake BayRestoration Framework

BayHealth

Factors Affecting

Bay Health

(Conditions in the Estuary)

(Conditions in the Watershed)

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Background Goals and Objectives Approach/Methods Timeline

WaterQualityGoals

Nutrient LoadReduction

Goals

Chesapeake Bay Total Maximum Daily Load (TMDL) for nitrogen, phosphorus, and sediment (Clean Water Act)

Meet Bay water quality criteria for dissolved oxygen, water clarity and chlorophyll-a concentrations

EcologicalEndpoints

PracticeImplementation

Goals

Water Quality in the Bay varies throughout space and

time

Landscape stressors originate from multiple

sectors, each with its own pathway to the Bay

Geography and Communication Challenges

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Background Goals and Objectives Approach/Methods Timeline

Bay Health: Water Quality Standards and the Chesapeake Bay TMDL

3 Geographic Dimensions

Temporal Dimension

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Background Goals and Objectives Approach/Methods Timeline

Bay Health: Water Quality Standards and the Chesapeake Bay TMDL

Vertical Stratification and the PycnoclinePycnocline - the region in a water column where water density changes rapidly, usually due to changes in salinity and temperature; in the Chesapeake Bay, the pycnocline region separates fresher, surface waters with a net flow down-Bay from saltier, bottom water with a net flow up-Bay.

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OpenWater

DeepWater

DeepChannel

Background Goals and Objectives Approach/Methods Timeline

• Since 1984, Maryland and Virginia routinely monitor 19 measured water quality parameters at 49 stations in the Bay’s main stem

• At least monthly sampling, with bi-weekly samples during June, July and August

• Hydrographic profile at 1-2 meter intervals at each station

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Bay Health: Chesapeake Bay Water Quality Data Base

Background Goals and Objectives Approach/Methods Timeline

Effective Science Communication• Guiding Principles (Thomas et al 2004)

• Synthesis – combining different data approaches, which can lead the user to novel insights

• Visualization – audience needs to see and interpret the data themselves

• Context – including comparative data so that specific examples can be characterized as “high” or “low” relative to regional or global extremes

User-centricEmphasis

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Background Goals and Objectives Approach/Methods Timeline

Project Goal

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Use commercial off-the-shelf GIS software to effectively communicate landscape and estuarine phenomena and to assist Chesapeake Bay Program scientists and managers to communicate (1) factors affecting Bay health and (2) measures of Bay health.

com

mun

icat

ion

publicprivate

high lowhuman-map interaction

presenting

knowns

revealing

unknowns

visu

aliza

tion

MacEachren and Taylor, 1994

Background Goals and Objectives Approach/Methods Timeline

Objectives

1. Significance of point and non-point pollution (nitrogen, phosphorus and sediment) loads to the Bay,

2. Significance of human population growth throughout the Bay watershed,

3. Extent of water quality designated use zones in the Bay,

4. Seasonal extent of the dissolved oxygen “dead zone”.

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Effectively communicate the …

BayHealth

Factors Affecting

Bay Health

(Conditions in the Estuary)

(Conditions in the Watershed)

… using 3D and temporal GIS

Background Goals and Objectives Approach/Methods Timeline

Audiences/Clients

• Partners• ChesapeakeStat website: stat.chesapeakebay.net

• Public • Chesapeake Bay Program website: www.chesapeakebay.net

Venues for Products

• Primary: Chesapeake Bay Program (CBP) Scientists and Resource Managers • Water Quality Goal Implementation Team (Agriculture,

Sediment, Urban Stormwater and Wastewater Workgroups)• Science, Technical Analysis and Reporting (STAR) Team

(Monitoring and Modeling Teams)• Communication Team

• Secondary: Interested Public

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Background Goals and Objectives Approach/Methods Timeline

Proposed Approach

Gather Requirements – define Communication

Stories

Work with CBP Monitoring Team, Modeling Team, and others to develop/affirm assessment questions and their context

Assemble Data

Data Manipulation - Conduct Analysis to Prepare Data for

Visualization

Grid development, surface generation (interpolation), conversion of interpolator output as necessary

– CBP Water Quality/Point Source Data Base– USGS SPARROW Model– US Census Data

Apply a VisualRepresentation Static and dynamic map and chart

views, animations, etc.

Iterate as

necessary

From Shapiro, M. 2010.

Background Goals and Objectives Approach/Methods Timeline

• Objective 1: Effectively communicate the significance of point and non-point pollution (nitrogen, phosphorus and sediment) loads to the Bay

• Data: USGS SPARROW Model and Chesapeake Bay Program Point Source Data Base

• Approach/Methods: Generate watershed-wide perspective views of point and non-point pollution sources from points and interpolated surfaces

• Anticipated Uses: Presentations and materials aimed at explaining where and from what source sectors pollution originates and their relative contributions

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Factors Affecting Bay HealthWatershed Pollution Loads

Background Goals and Objectives Approach/Methods Timeline

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Factors Affecting Bay HealthWatershed Pollution Loads

• Point Sources• 486 Significant Municipal and Industrial Point

Sources in Chesapeake Bay Watershed• Typically presented in tabular view and 2D

graduated color point symbols

• Non-Point Sources• Spatially Referenced Regression (SPARROW)

model for evaluation of nitrogen, phosphorus and sediment loads (Preston and Brakebill 1999)

• Typically represented via 2D choropleth maps

N Loadsfrom

Agriculture

Background Goals and Objectives Approach/Methods Timeline

VA

MDWV

NYPA

DEDC

Factors Affecting Bay HealthSPARROW – from 2D to Perspective Views

HydrologicSegmentation

Example – Nitrogen Loads from Agricultural Sources

Modeled N Loadsfrom Agricultureaggregated to

Watersheds

Assignment of N LoadValue to Watershed

Centroid

Surface Generation/Interpolation

Background Goals and Objectives Approach/Methods Timeline

180019002000

• Objective 2: Effectively communicate the significance of human population growth throughout the Bay watershed

• Data: US Census County population (1790-2010)

• Approach/Methods: Generate perspective views of extruded county polygons and animate the decadal change

• Anticipated Uses: Presentations and materials describing the role of population growth as a landscape stressor and the need to incorporate growth into future decisions

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Factors Affecting Bay HealthPopulation Growth and Development

Background Goals and Objectives Approach/Methods Timeline

• Objective 3: Effectively communicate the extent of water quality designated use zones in the Bay

• Data: Chesapeake Bay Program Water Quality Data Base, Chesapeake Bay segmentation Scheme, and bathymetry

• Approach/Methods: Utilize historical Chesapeake Bay monitoring station data to generate pycnocline boundaries and generate cross-sections illustrating the variability in designated use zones throughout the Bay

• Anticipated Uses: Presentations and materials describing the regulatory implications of water quality standards and how they vary with geography and water depth

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Bay HealthWater Quality Designated Use Zones

Background Goals and Objectives Approach/Methods Timeline

Bay HealthWater Quality Designated Use Zones

BayBathymetry

MonitoringStation LE 2.2

Conceptual Framework

Actual Delineation of the Pycnocline and associated Designated Use Zones at Station LE 2.2 based on

Monitoring Station- Specific Water Density

Gradients(USEPA 2003)

ShallowWater

OpenWater

Deep Water(pycnocline)

DeepChannel

Dep

th (m

)

Bathymetric Profile LE 2.2

Chesapeake Bay Designated Use Zones7,0006,0005,0004,0003,0002,0001,0000

0

-2

-4

-6

-8

-10

-12

-14

Background Goals and Objectives Approach/Methods Timeline

JanuaryAprilJulyOctober

• Objective 4: Effectively communicate the seasonal extent of the area of hypoxia (“dead zone”) in the Bay

• Data: Chesapeake Bay Program Water Quality Data Base

• Approach/Methods: Utilize Chesapeake Bay interpolator output to generate bi-weekly/weekly depictions of the dead zone at multiple depths

• Anticipated Uses: Presentations and materials explaining the temporal nature of water quality conditions and the seasonality of problems associated with meeting standards

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Bay HealthSeasonal Variation in “Dead Zone”

Background Goals and Objectives Approach/Methods Timeline

Bay HealthChesapeake Bay Interpolator

• Cell based interpolator (VOL3D) that computes water quality concentrations throughout the Bay and tidal tributaries from water quality measured at point locations (Bahner 2006)

• Code is optimized to compute concentration values which closely reflect the physics of stratified water bodies

• Bay is very shallow compared to its width or length, hence water quality varies much more vertically than horizontally

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Background Goals and Objectives Approach/Methods Timeline

Project Timeline• Week 1: Gather requirements/communication stories• Week 2-3: Assemble and organize data

– CBP Water Quality Database– Request/generate VOL 3D interpolator output for specific parameters and dates– Organize SPARROW model data

• Week 4-5: – Develop draft visualizations – Bay Health and Factors Affecting Bay Health

• Week 6:– Solicit feedback from Monitoring and Modeling Teams

• Weeks 7-8:– Revisions to visualizations as necessary

• Week 9– Develop sample animations

• Week 10:– Develop final product documentation and presentation at AAG

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Background Goals and Objectives Approach/Methods Timeline

ReferencesAndrienko, N. and G. Andrienko. 2006. Exploratory Analysis of Spatial and Temporal Data: A

Systematic Approach. Springer-Verlag Berlin Heidelberg.

Bahner, L. 2006. User Guide for the Chesapeake Bay and Tidal Tributary Volumetric Interpolator. NOAA Chesapeake Bay Office, Annapolis, MD.

MacEachren A. and D. Taylor. 1994. Visualization in Modern Cartography. New York: Elsevier Science Inc.

National Research Council. 2011. Achieving Nutrient and Sediment Reduction Goals in the Chesapeake Bay: An Evaluation of Program Strategies and Implementation. Committee on the Evaluation of Chesapeake Bay Program Implementation for Nutrient Reduction to Improve Water Quality The National Academies Press. Washington, D.C.

Preston, S. and J. Brakebill. 1999. Application of Spatially Referenced Regression Modeling for the Evaluation of Total Nitrogen Loading in the Chesapeake Bay Watershed. USGS Water-Resources Investigations Report 99-4054.

Shapiro, M. 2010. Once Upon a Stacked Time Series. In Beautiful Visualization. J. Steele and N. Ilinsky, eds. O’Reilly. Sebastopol, CA.

Thomas, J., A. Jones, T. Saxby, T. Carruthers, E. Abal, and W. Dennison. 2004. Communicating Science Effectively: A practical handbook for integrating visual elements. University of Maryland Center for Environm3ntal Science.

Tufte, E. 1983. The Visual Display of Quantitative Information. Graphics Press. Cheshire, CT. \

USEPA. 1983. Technical Support Document for Identification of Chesapeake Bay Designated Uses and Attainability. United States Environmental Protection Agency Region III Chesapeake Bay Program Office. EPA 903-R-03-004. Annapolis, MD

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Acknowledgement

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Dr. Patrick KennellyMGIS Faculty Advisor

Questions?

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