Communicating Chesapeake Bay Water Quality
Issues Using 3D and Temporal GIS
John Wolf
Capstone 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
2
Background
Goals and Objectives
Approach/Methods
Timeline
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
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
3
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
4
Background
Goals and Objectives
Approach/Methods
Timeline
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
Overview of Chesapeake Bay
Restoration Framework
Practice
Implementation
Goals
Watershed Implementation Plans
and State 2-Year Milestones for
practice implementation
Nutrient Load
Reduction
Goals
Chesapeake Bay Total
Maximum Daily Load (TMDL) for
nitrogen, phosphorus, and
sediment (Clean Water Act)
Water
Quality
Goals
Meet Bay water quality criteria for
dissolved oxygen, water clarity and
chlorophyll-a concentrations
Ecological
Endpoints
Restoration of underwater grasses,
fisheries, benthic communities, and faunal
diversity
Factors
Affecting
Bay Health
(Conditions in the
Watershed)
Bay
Health
(Conditions in the
Estuary)
Adopted from National Research Council 2011
6
Background
Goals and Objectives
Approach/Methods
Timeline
Geography and Communication Challenges
Practice
Implementation
Goals
Nutrient Load
Reduction
Goals
Water
Quality
Goals
Ecological
Endpoints
Landscape stressors
originate from multiple
sectors, each with its own
pathway to the Bay
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
Water Quality in the Bay
varies throughout space and
time
7
Background
Goals and Objectives
Approach/Methods
Timeline
Bay Health: Water Quality Standards and
the Chesapeake Bay TMDL
3 Geographic
Dimensions
Temporal
Dimension
8
Background
Goals and Objectives
Approach/Methods
Timeline
Bay Health: Water Quality Standards and
the Chesapeake Bay TMDL
Open
Water
Deep
Water
Deep
Channel
Vertical Stratification and the Pycnocline
Pycnocline - 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.
9
Background
Goals and Objectives
Approach/Methods
Timeline
Bay Health: Chesapeake Bay Water
Quality Data Base
• 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
10
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-centric
Emphasis
11
Background
Goals and Objectives
Approach/Methods
Timeline
Project Goal
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.
public
private
high
low
human-map interaction
MacEachren and Taylor, 1994
12
Background
Goals and Objectives
Approach/Methods
Timeline
Objectives
Effectively communicate the …
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”.
… using 3D and temporal GIS
Factors
Affecting
Bay Health
(Conditions in the
Watershed)
Bay
Health
(Conditions in the
Estuary)
13
Background
Goals and Objectives
Approach/Methods
Timeline
Audiences/Clients
• 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
Venues for Products
• Partners
• ChesapeakeStat website: stat.chesapeakebay.net
• Public
• Chesapeake Bay Program website: www.chesapeakebay.net
14
Background
Goals and Objectives
Approach/Methods
Timeline
Proposed Approach
Gather Requirements –
define Communication
Stories
Assemble Data
Work with CBP Monitoring Team,
Modeling Team, and others to
develop/affirm assessment questions
and their context
–CBP Water Quality/Point Source Data Base
–USGS SPARROW Model
–US Census Data
Data Manipulation - Conduct
Analysis to Prepare Data for
Visualization
Grid development, surface
generation (interpolation),
conversion of interpolator output as
necessary
Apply a Visual
Representation
Static and dynamic map and chart
views, animations, etc.
Iterate
as
necessary
From Shapiro, M. 2010.
Background
Goals and Objectives
Approach/Methods
Timeline
Factors Affecting Bay Health
Watershed Pollution Loads
• 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
16
Background
Goals and Objectives
Approach/Methods
Timeline
Factors Affecting Bay Health
Watershed 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
N Loads
from
Agriculture
• 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
17
Background
Goals and Objectives
Approach/Methods
Timeline
Factors Affecting Bay Health
SPARROW – from 2D to Perspective Views
Example – Nitrogen Loads from
Agricultural Sources
NY
PA
WV
MD
DC
VA
DE
Hydrologic
Segmentation
Modeled N Loads
from Agriculture
aggregated to
Watersheds
Assignment of N Load
Value to Watershed
Centroid
Surface Generation/
Interpolation
Background
Goals and Objectives
Approach/Methods
Timeline
Factors Affecting Bay Health
Population Growth and Development
• 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
2000
1900
1800
19
Background
Goals and Objectives
Approach/Methods
Timeline
Bay Health
Water Quality Designated Use Zones
• 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
20
Background
Goals and Objectives
Approach/Methods
Timeline
Bay Health
Water Quality Designated Use Zones
Conceptual Framework
Bay
Bathymetry
Monitoring
Station LE 2.2
Shallow
Water
Bathymetric Profile LE 2.2
0
Open
Water
-2
(USEPA 2003)
-4
Depth (m)
Actual Delineation of the
Pycnocline and associated
Designated Use Zones at
Station LE 2.2 based on
Monitoring StationSpecific Water Density
Gradients
Deep Water
(pycnocline)
-6
-8
-10
Deep
Channel
-12
-14
0
1,000
2,000
3,000
Chesapeake Bay Designated Use Zones
4,000
5,000
6,000
7,000
Background
Goals and Objectives
Approach/Methods
Timeline
Bay Health
Seasonal Variation in “Dead Zone”
• Objective 4: Effectively communicate the
seasonal extent of the area of hypoxia (“dead
zone”) in the Bay
October
January
July
April
• 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
22
Background
Goals and Objectives
Approach/Methods
Timeline
Bay Health
Chesapeake 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
23
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
24
References
Andrienko, 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
25
Acknowledgement
Dr. Patrick Kennelly
MGIS Faculty Advisor
26
Questions?
27