Interpreting and Presenting Data
Baseline and Hotspot Monitoring
Define
questions
Collect water
quality data
Manage data
Interpret data
Present data
TAKE ACTION!
Steps for Data Interpretation
1.
2.
3.
4.
5.
Go back to your original question
Describe the data
Play with data graphically
Plug in additional information
Summarize conclusions and further
questions
Sample baseline questions:
• What are summer dissolved oxygen levels on
Gallagher Slough? Are oxygen concentrations
high enough to support salmon?
• How do bacteria concentrations on Beaver Creek
compare with the state standard for water contact
recreation?
• Do pH concentrations on Birch Creek exceed the
state standard? If so, when?
Descriptive Statistics
• What is the “central tendency”? (mean,
median, mode)
• How does one reading compare to the rest?
(50th, 75th, 25th percentiles)
• What’s the variation? (range, variance,
standard deviation)
Compare using box and whisker plot
12
10
Frequency
8
6
4
2
0
0-4
5-9
10-14
15-20
mg/L Dissolved Oxygen
If you have a lot of data, collected regularly, it may be useful to see
how the data are distributed. When is this NOT useful?
Arrange Data Graphically
•
•
•
•
Identify patterns and trends
Quickly confirm or disprove hypotheses
Discover new phenomena
Identify potential problems with data
collection
• Communicate initial results to partners,
“Gasp”
funders, etc.
I can’t believe my
eyes!
Examples of Useful Graphs
• Box-and-whisker plot
• Scatter plot
• Time plot
Example:
• What are summer dissolved oxygen
concentrations on Gallagher Slough? Are
concentrations high enough to support
salmon?
Dissolved Oxygen
6/1/02-10/1/02
Dissolved Oxygen (mg/L)
10
9
16
16
14
8
7
6
5
4
3
2
1
max
min
Average
Salmon, trout die
0
Gallagher Slough
Mill Creek
Site
Beaver Creek
Plot data against time
16
14
DO (mg/L)
12
10
Level recommended by DEQ
8
6
4
2
0
3/20/2003
5/9/2003
6/28/2003
8/17/2003
10/6/2003
11/25/2003
Date
What are summer dissolved oxygen levels on Gallagher Slough?
Are oxygen concentrations high enough to support salmon?
What baseline / standard are you
using?
•
•
•
•
A biological baseline
A water quality standard
Other
Go back to your original question
What else do you know about DO that
can help you answer your question?
What else do you know?
• Warmer water can hold less DO
• Algae give off oxygen when they respire
during the day
• Algae use oxygen when they decompose
• DO concentrations can be lowest late at
night
What other information might be
helpful?
•
•
•
•
Temperature data
Flow information
Site characteristics
Observations about the stream reach
(Visible algae? Obvious nutrient sources?)
Challenges for Interpreting Data
• Available resources (can’t monitor
continuously everywhere)
• Hard to pinpoint location and timing of
extremes
• May have to do some hypothesizing
Umatilla River at Yoakum
pH
10
pH Units
pH standard upper limit (for eastern Oregon rivers)
9
8
7
pH standard lower limit
6
6/19/97
1/5/98
7/24/98
Date
2/9/99
8/28/99
Identifying Hot Spots
• Identifying reaches with high / low readings
• Identifying sites with very high / low
readings
• Comparing results from different sites
Comparing Sites
•
•
•
•
Graphically
Using tables
Using maps
This is a judgment call
Box and whisker plot plus standard by each site
Total Phosphorus, Ninilchik River, Alaska
l-0
1
1
1
n02
O
ct
-0
l-0
r-0
Ju
Ap
Ja
0
0
0
n01
O
ct
-0
Ju
r-0
2000
Ja
9
n00
Ap
Ja
O
ct
-9
E. Coli (mpn/100 mL)
Trask River
2500
•Upper Trask
•Mill Creek
•Upstream of Tillamook
1500
1000
500
0
Three Wilson River Sites
e. coli (mpn) / 100 mL
2500
2000
1500
1000
500
0
9
0
1
1
0
1
1
2
0
0
0
0
00 r-00
0
0
0
-t 9
r
n
n
n
c
ul
ct
ul
ct
p
p
a
a
a
J
J
O
O
A
O
A
J
J
J
Date
Data Summary
Site
Days > 64 F
Days >70 F
1
66
12
2
21
0
3
48
0
4
8
0
5
0
0
Strengths / drawbacks associated with this method?
Sites that violate the bacteria quality standard in August
Miami R.
Kilchis R.
Wilson R.
Trask R.
Tillamook
R.
Tillamook River and Tributaries
August 2001
E. Coli Concentration (Geomean)
2500
2000
1500
tributaries
Bewley Creek
1000
500
Bacteria standard
0
TL7
TL6
TL5
TL4
TL2
TL8
TL3
TL1
Summary for Data Interpretation
1.
2.
3.
4.
5.
Go back to your original question
Describe the data
Play with the data graphically
Plug in additional information
Write down your conclusions and further
questions
Presenting Water Quality
Information
Getting Your Message Across
Planning Your Data Presentation
•
•
•
•
Focus on your message
Decide on target audience
Decide how the message will be delivered
Pick your time and place
Take home
message:
Inform!
Educate!
Persuade!
Focus on Your Message
Help! Bacteria levels
violate Oregon’s
standard!
• Go back to your study
design and results
• Review your questions
and conclusions
• Stick to them!
• Make sure presenter
understands the
message
Sample messages:
• Stream meets standard for bacteria; BMPs
can keep it that way
• Bacteria levels show a risk for swimming
• Japanese knotweed is in our area; action is
needed now
Issue: Mill Creek, which drains a rural-residential area,
violates Oregon’s bacteria standard every August.
Potential sources include failing septic systems, pets, and
wildlife.
Potential Audience
•
•
•
•
Chamber of Commerce
General public
Neighborhood residents
County sanitary program
Mill Creek, which drains a rural-residential area,
violates Oregon’s bacteria standard every August.
Potential sources included failing septic systems, pets,
and wildlife.
Knowledge needed for action:
1.
2.
3.
4.
Watershed processes
Condition of water body
Causes of current conditions
Sources of pollution or
related problems
5. Consequences
6. Solutions
Data
Factual information used as a
basis for reasoning,
discussion, or calculation
Information
Communication or reception
of knowledge or intelligence
What motivates people?
•
•
•
•
•
•
•
Crisis
Enthusiasm
Guilt
Public Image
Self Interest
Help
Fear?
Choose format to match audience
•
•
•
•
•
•
Slide show?
One-on-one meeting?
Report?
Flyer?
Presentation?
News article?
Thousands of Mitten Crabs
Graphics
Point of no return
CA Dept. of Fish and Game
Time
Maps and Aerial Photos
Source
Transport
Deposition
Stream Reach Types, Cascade Creek
Bacteria levels violate Oregon’s standard
for water recreation in August
Bacteria levels are below Oregon’s
standard for water recreation in August
Turbidity during
first fall storm, in
NTUs
0-20 NTUs
21-50 NTUs
>50 NTUs
wetland
Monitoring
point
Dissolved Oxygen Concentration
Blind Slough Near Highway 101
Salmon and trout
stressed
10
7/
3/
20
02
7/
11
/2
00
2
7/
18
/2
00
2
7/
26
/2
00
2
8/
4/
20
02
8/
9/
20
02
8/
23
/2
00
2
8/
30
/2
00
2
9/
6/
20
02
9/
13
/2
00
2
9/
21
/2
00
2
9/
26
/2
00
2
6/
25
/2
00
2
12
45
#6 - East Bridge
Series1
Series3
Series4
8
4
0
40
35
30
25
6
20
15
10
2
5
0
A Word On Tables
• Make as simple as possible
• Better for an audience already familiar with
what you’re doing
• Explain clearly in text or presentation
Effects of Urbanization on
Peak Stream Flows
# of
Years of
# of Times
Year Houses Flow Data Flow>220cfs
# of Times
Flow >350cfs
1950
140
None
No Data
No Data
1955
420
None
No Data
No Data
1965
780
1958-1967
21
10
1984
2060
1978-1987
73
32
Watts Branch, MD. (Leopold, 1994)
220cfs is considered an 1.5 year event
Photos
For More Information
Ready, Set, Present!
Massachusetts Water Watch Partnership
http://www.umass.edu/tei/mwwp/
(check under manuals and publications)
$5!
Discusses brochures, displays, newsletters…etc.
In Summary
• Plan your strategy
• Inform, educate, persuade
• Use graphics to strengthen your case
During winter storms, animal waste is
washed into the river.