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 Interpretation1. Go back to your original question2. Describe the data3. Play with data graphically4. Plug in additional information5. 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

0

2

4

6

8

10

12

0-4 5-9 10-14 15-20mg/L Dissolved Oxygen

Freq

uenc

y

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,

funders, etc. “Gasp”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

0123456789

10

Gallagher Slough Mill Creek Beaver CreekSite

Dis

solv

ed O

xyge

n (m

g/L)

maxminAverage

16 14 16

Salmon, trout die

Plot data against time

What are summer dissolved oxygen levels on Gallagher Slough? Are oxygen concentrations high enough to support salmon?

0

2

4

6

8

10

12

14

16

3/20/2003 5/9/2003 6/28/2003 8/17/2003 10/6/2003 11/25/2003

Date

DO

(mg/

L) Level recommended by DEQ

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 YoakumpH

Date

6

7

8

9

10

6/19/97 1/5/98 7/24/98 2/9/99 8/28/99

pH U

nits

pH standard lower limit

pH standard upper limit (for eastern Oregon rivers)

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

Trask River2500

•Upper Trask

•Mill Creek

•Upstream of Tillamook

E. C

oli (

mpn

/100

mL) 2000

1500

1000

500

0

Oct-99

Jan-0

0Apr-

00Ju

l-00

Oct-00

Jan-0

1Apr-

01Ju

l-01

Oct-01

Jan-0

2

0

500

1000

1500

2000

2500

Oct-99

Jan-0

0

Apr-00

Jul-0

0

Oct-00

Jan-0

1

Apr-01

Jul-0

1

Oct-01

Jan-0

2

Date

e. c

oli (

mpn

) / 1

00 m

LThree Wilson River Sites

Data SummarySite 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?

Miami R.

Kilchis R.Wilson R.

Trask R.

Tillamook R.

Sites that violate the bacteria quality standard in August

Tillamook River and TributariesAugust 2001

0

500

1000

1500

2000

2500

TL7 TL6 TL5 TL4 TL2 TL8 TL3 TL1

E. C

oli C

once

ntra

tion

(Geo

mea

n)

Bewley Creektributaries

Bacteria standard

Summary for Data Interpretation1. Go back to your original question2. Describe the data3. Play with the data graphically4. Plug in additional information5. 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• Go back to your study

design and results• Review your questions

and conclusions• Stick to them!• Make sure presenter

understands the message

Help! Bacteria levels violate Oregon’s standard!

Sample messages:

• Stream meets standard for bacteria; BMPscan 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

Knowledge needed for action:

1. Watershed processes2. Condition of water body3. Causes of current conditions4. Sources of pollution or

related problems5. Consequences6. Solutions

Mill Creek, which drains a rural-residential area, violates Oregon’s bacteria standard every August. Potential sources included failing septic systems, pets, and wildlife.

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?

Graphics

Thou

sand

s of M

itten

Cra

bs

Point of no return

CA Dept. of Fish and GameTime

Maps and Aerial PhotosSource

Transport

Deposition

Stream Reach Types, Cascade Creek

Bacteria levels violate Oregon’s standard for water recreation in AugustBacteria levels are below Oregon’s standard for water recreation in August

0-20 NTUs

21-50 NTUs

>50 NTUs

Turbidity during first fall storm, in NTUs

wetland

Monitoring point

Dissolved Oxygen Concentration

Blind Slough Near Highway 101

Salmon and trout stressed

0

2

4

6

8

10

12

6/25/2

002

7/3/20

027/1

1/200

27/1

8/200

27/2

6/200

28/4

/2002

8/9/20

028/2

3/200

28/3

0/200

29/6

/2002

9/13/2

002

9/21/2

002

9/26/2

002

0

5

10

15

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25

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40

45

#6 - East BridgeSeries1Series3Series4

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

Year# of Houses

Years of Flow Data

# of Times 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 InformationReady, 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.