Eco-hydraulic modeling for river restoration

Isabel Boavida António Pinheiro

Introduction

Restore the ecological conditions of natural rivers:

• create upstream and downstream fish passes,

• implement instream flows,• improve longitudinal and lateral

connectivity, • and, protect habitat and ecosystems.

The restoration projects tests the possibility of recreating complex ecosystems, allowing fish to meet their biological needs for feed, migration, reproduction and shelter.

Restoration projects

River Ecosystem

Water

Human interactions

River bed

Riparianvegetation

River Ecosystem

River habitats

Along the river the habitat changes

During the year the habitat changes

Each river have different habitat

River habitats

River scale

Habitat

Stream

Segment

Basin

Microhabitat

Pool, riffle, run…

Velocity

Depth

Substrate

River habitats

Run

Pool

Riffle

Waterfall

Lateral channel

Habitat requirements for fish

Different species live in different habitats and in their

life-cycle they occupy different habitat

Light intensity

Stream substrate

Hydraulic characteristics

Biotic variables

Microhabitat

Habitat requirements for fish

Hydraulic characteristics

DepthVelocity

Qin = 1.300 Qout = 1.299

X

Y

30985.060

30835.080166402.129166114.401

Depth

0.02

0.74

0.67

0.59

0.52

0.45

0.38

0.31

0.24

0.16

0.09

0.02

Restore the natural habitats that use to exist in the river

River rehabilitation

Habitat modeling

Eco-hydraulic modeling analyze the relationship between fish habitat and stream flows.

Habitat as a function of discharge

Índice compósito de preferência do escalo juvenil primavera-verão Qin = 2.050 Qout = 2.048

X

Y

30994.716

30825.425166382.231166134.299

Combined Suitability

0.00

0.79

0.71

0.63

0.55

0.47

0.39

0.31

0.24

0.16

0.08

0.00Distance10.0 m

0

50

100

150

200

250

0 1 2 3 4 5 6 7 8 9

Flow (m3/s)

WUA

(m2 )

Habitat modeling

Using models to assess river restoration success

Velocidade no troço da ribeira de Odelouca Qin = 2.050 Qout = 2.048

X

Y

30994.716

30825.424166382.231166134.299

Velocity

0.00

1.05

0.95

0.84

0.74

0.63

0.53

0.42

0.32

0.21

0.11

0.00Distance10.0 m

Qin = 1.300 Qout = 1.302

X

Y

30985.060

30835.080166402.129166114.401

Depth

0.02

0.68

0.62

0.55

0.49

0.42

0.35

0.29

0.22

0.15

0.09

0.02

-120-100

-80-60-40

-200

20

4060

Meanderingwith submerged

weirs

Meanderingwith two-islands

Islands in themiddle of the

channel Lateral bays Lateral

deflectors

Mea

n m

onth

ly in

crea

se a

nd d

ecre

ase

of W

UA

(%)

Adults Juvenils

2D model

Jardas River

Woorkshop objectives

• Characterize and quantify the different habitats of JardasRiver;

• Propose restoration actions.

Jardas River

1. Identifying different fish habitats

• Characterize the different habitat in Jardas River;• Quantify the distribution of habitats in Jardas River.

Pool, riffle, run, lateral channel…

Jardas River

2. Hydraulic data collection in cross-section

(Q = 2,05 m3/s)

9.59.69.79.89.910

10.110.210.310.410.5

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Distance to right bank (m)

Z (m

)

• Depth, velocity and substrate in different habitat.

Jardas River

3. Electric fish sampling

• Identify the species in the Jardas River;• Characterize the habitat of the species.

Curva de preferência para ESCALO

00.20.40.60.8

1

<20 20-40 40-60 60-80 80-100 >100

Profundidade (cm)

Pref

erên

cia

alevins juvenis adultos

(Q=2,05 m3/s)

00.1

0.20.30.4

0.50.60.70.80.9

6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Distance to right bank (m)

Velo

city

(m/s

)

Jardas River

(Q = 2,05 m3/s)

9.59.69.79.89.910

10.110.210.310.410.5

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Distance to right bank (m)

Z (m

)

4. Characterize the hydraulic of the different habitats

• Characterize the hydraulic characteristics that define each habitat.

Pool

Jardas River

5. Characterize the composition of habitats in the river

Riffle

Pool Run Pool

River

Jardas River

7. Conclusions

6. Propose different rehabilitation scenariosQin = 1.300 Qout = 1.363

X

Y

30977.474

30843.128166387.603166129.868

Depth

0.00

0.81

0.73

0.65

0.57

0.49

0.41

0.33

0.24

0.16

0.08

0.00

Qin = 1.300 Qout = 1.299

X

Y

30985.060

30835.080166402.129166114.401

Depth

0.02

0.74

0.67

0.59

0.52

0.45

0.38

0.31

0.24

0.16

0.09

0.02

End