Influences of Storm Events on Mission-Aransas Estuary and the

Recovery

Qiyuan Liu

(Coworker - Aubrey Lashaway)

Overview

• What: Mission-Aransas Estuary

• Why: Objectives for the project

• How: Results

• What’s next: Future work

Mission-Aransas National Estuarine Research Reserve

(MA-NERR)

Copano SubwatershedMisssion

SubwatershedAransas Subwatershed

Copano SubwatershedMisssion

SubwatershedAransas Subwatershed

Advantages of target area

• Relatively pristine ecosystem

• Texas’s climate: variable

Extreme weather events

Amount and timing of rainfall

Freshwater inflows

Abrupt changes in estuary

Abiotic factors: water quality

Biotic factors: diversity & function

Goals & Methods:• Precipitation &

Stream discharge• Water quality before & after storm

• Influence of up-stream watersheds storm events on estuary and recovery

Precipitation – Storm EventAverage Daily Precipitation for Bee County, Texas

0

2

4

6

8

10

12

2007-1-1

2007-2-1

2007-3-1

2007-4-1

2007-5-1

2007-6-1

2007-7-1

2007-8-1

2007-9-1

2007-10-1

2007-11-1

2007-12-1

Prec

ipita

tion

(inch

es)

Copano Ck nr Refugio, TX

Mission RV at Refugio, TX

Aransas RV nr Skidmore, TX

Medio CK nr beeville, TX

Stream Discharge Gauge Stations

Stream DischargeDischarge: Mission-Aransas Catchment Gages

0

2000

4000

6000

8000

10000

12000

14000

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Dis

char

ge (c

fs)

Copano Ck nr Refugio, TXMedio Ck nr Beeville, TXMission Rv at Refugio, TXAransas Rv nr Skidmore, TX

Water Quality Gauge Stations

Copano Bay East Copano Bay West

SalinitySalinity: Copano East

0

5

10

15

20

25

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Salin

ity (p

pt)

Salinity: Copano West

0

1

2

3

4

5

6

7

8

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Salin

ity (p

pt)

Stream Discharge Gauges

Water Quality Gauge Stations

Stream Discharge and Salinity 2007-7-8 00:00

Salinity: Copano East

0

5

10

15

20

25

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Salin

ity (p

pt)

Discharge: Mission-Aransas Catchment Gages

0

2000

4000

6000

8000

10000

12000

14000

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Dis

char

ge (c

fs)

Copano Ck nr Refugio, TXMedio Ck nr Beeville, TXMission Rv at Refugio, TXAransas Rv nr Skidmore, TX

Average Daily Precipitation for Bee County, Texas

0

2

4

6

8

10

12Pr

ecip

itatio

n (in

ches

)

July 4th, 2007

Dissolved OxygenDissolved Oxygen: Copano East

0

2

4

6

8

10

12

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Dis

solv

ed O

xyge

n (m

g/L)

Dissolved Oxygen: Copano West

0

2

4

6

8

10

12

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Dis

solv

ed O

xyge

n (m

g/L)

Stream Discharge & DODischarge: Mission-Aransas Catchment Gages

0

2000

4000

6000

8000

10000

12000

14000

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Dis

char

ge (c

fs)

Copano Ck nr Refugio, TXMedio Ck nr Beeville, TXMission Rv at Refugio, TXAransas Rv nr Skidmore, TX

Dissolved Oxygen: Copano East

0

2

4

6

8

10

12

2007-6-1 2007-7-2 2007-8-2 2007-9-2 2007-10-3 2007-11-3 2007-12-4

Dis

solv

ed O

xyge

n (m

g/L)

Conclusions• Storm events can greatly influence the water

quality such as salinity, DO, etc in downstream

estuary.

• There would be a delay in the change of water

quality after a storm event.

• It will take about 5 months for an estuary to recover

from storm, with little permanent effect

Future Work• Compare the change in salinity in different gauge

stations which serve different functions in the estuary.

• Provide interpolation of salinity in estuary before and

after storm

• Storm influences on estuarine ecosystem –

biodiversity, composition and function of communities.