msc thesis

Monitoring and evaluation of environmental impacts of port interventions during 2000-

2001, on the Mondego estuary sedimentary system and adjacente coast

João Pedro C. A. Mendes

IndexChapter I - Introduction

Chapter II - Beach Profiles

Chapter III -Topohydrographic Surveys

Chapter IV - Sedimentary Solid Transport

Chapter V - Synthesis e Conclusions

Objectives

Improve and quantify of natural controles;

Monitoring Beach evolution;

Quantify rates of sedimentary evolution;

Apply GIS calculus to the study of sedimentary dynamics;

Contribute for sustainable management of this coastal area.

MethodologyField work

Taking beach profiles. Monitoring river and coastal dredging.

Office work Topohydrographic Surveys analysis. Managing Data into a GIS system (3D imaging,

numeric modelling, graphic exploration, 4D imaging and interpretation).

Geographical Location

(a) Distal(b) Intermédio(c) Próximal

Ada

ptad

o de

Cun

ha, 1

998

Controls of sedimentary dynamics The Sea as a controling agent

Influence on coastal sedimentary evolution

Influence on Longshore sedimentary transport

(ºN) % (m) % (s) %

≤ 220 1,1 calma 1,1 ≤ 8 2,2]220, 240] 1,6 ]0 a 1] 30 ]8, 10] 6]240, 260] 1,1 ]1 a 2] 50 ]10, 12] 35]260, 280] 33 ]2 a 3] 13 ]12, 14] 47]280, 300] 20 ]3 a 4] 4,1 ]14, 16] 8,2]300, 320] 43 ]4 a 5] 2,5 ]16, 18] 1,4

]5 a 6] 0,3

Direction Height Period

Wave characteristics 2001

Monitoring sea level

0,720,68

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

12-01-2001 17-01-2001 22-01-2001 27-01-2001 01-02-2001 06-02-2001 11-02-2001

Altura (Z.H.)Altura de agitação marítimaNível Médio

Dredging areas

Limite de jurisdiçãoLimite de jurisdiçãoSector Comercial

Porto de

Pesca

Marina

Ponte da Gala

Terminalde Granéis

Terminal deCarga Geral

Limite de jurisdição

In the Port´s Fishing Dock;

- In the navigational channel and Port

entrance.A

dapt

ado

de I

.P.C

., 04

/08/

2000

Dredging monitored

0

200

400

600

800

1.000

1.200

1.400

1.600

1.800

2.000

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

Milh

are

s (

m3)

Dragagens portuáriasExtracção de areia na embocadura, anteporto e barraExtracção de areia na praia

38

115

70

3245

23

195

150

187

10105

60

128

0

20

40

60

80

100

120

140

160

180

200

Jul-00

Ago-00

Set-

00

Out-

00

Nov-00

Dez-00

Jan-01

Fev-01

Mar-01

Abr-01

Mai-01

Jun-01

Jul-01

Ago-01

Set-

01

Out-

01

Nov-01

Milhares (

m3)

II- Beach Profiles

Sedimentary behaviour of exposed beach

Beach profile analysis

1

2

3

4

5

6

Ada

ptad

o de

Cun

ha &

Din

is, 1

998

Ort

ofot

o C

.M.F

.F.,

1998

Perfis elaborados no local Bola de Nívea,de 29/09/2000 a 07/10/2001

0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

29.9.003.10.004.11.005.12.0015.01.0110.02.0117.03.0115.04.0113.05.0117.06.0117.07.0129.08.0107.10.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 29.9.00


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

29.9.00

3.10.00


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 3.10.00


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

3.10.00

4.11.00


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 4.11.00


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

4.11.00

5.12.00


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 5.12.00


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

5.12.00

15.01.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 15.01.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

15.01.01

10.02.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 10.02.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

10.02.01

17.03.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 17.03.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

17.03.01

15.04.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 15.04.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

15.04.01

13.05.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 13.05.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

13.05.01

17.06.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 17.06.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

17.06.01

17.07.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 17.07.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

17.07.01

29.08.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 29.08.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

29.08.01

07.10.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m) 07.10.01


0

1

2

3

4

5

6

7

8

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Distância (m)

Cot

as (

m)

29.9.003.10.004.11.005.12.0015.01.0110.02.0117.03.0115.04.0113.05.0117.06.0117.07.0129.08.0107.10.01

II – Beach Profiles

Profile 5 evolution29/09/2000 to 07/10/2001

50

250

450

650

850

353400354900356400 LatitudeÁre

a (m

2)

29-09-200030-09-200003-10-200005-10-200004-11-200005-12-200015-01-200110-02-200117-03-200115-04-200113-05-200114-06-200117-06-200117-07-200129-08-200131-08-200107-10-2001

Evolution of the sedimentary prism per stationEvolution of the sedimentary prism per station

chaminé

cemitério

Rotundafarolim

Bola NíveaThe variability is explained by:

-Sea charachteristics; -Morphology of the longshore bar and beach; - Exposure of the coast line.

Topohydrographic Surveys Analysis

21/11/2001

29/08/2001

AB

A – Active area of sedimentary transportB – Deeper Longshore bar

4D Bathymetric Map of

Sedimetary evolution

Am = 1,5 m; Rm = N281º; Tm = 12 s;

Dredged = 283 656 m3

Balance = -37 738 m3

(449,26 m3/day)

Am = Average Height of wave;

; Rm = Average Directional wave;

Tm = Period of the wave

Analysis of deepwater estuary sediment and nearby coast

For this analysis we took into account:

• sedimentary removal

• Time scale of the analysed area

• Sea characteristics (Wave height, Direction, Periods)

21/02/2001

• Fluvial discharge (ex.: flood effect)

Sedimentary infilling of Port entrance (21/02/2001)Sedimentary flows related to currents;

Human intervention area; Am = 2,4 m; Rm = N286º; Tm = 13 s;

Dredged = 46 909 m3 (1 066,11 m3/dia); Bal. = 148 058 m3 (0,008 m3/day);

Fishing Dock4D calculus

A

B

C

30/03/2001 – 02/07/2001Biggest loss = 143 949 m3

Lowered Bathymetry= -1,78 m (-0,019m/day)

02/07/2001 – 23/072001Gain= 18 558 m3

Loss = 51 486 m3

Balance = -32 928 m3

30/03/2001 – 02/07/2001Bal. = -33 643 m3

Average bathymetric lowering of -0,011m/dayAverage growth [0,001; 0,011] m/day

30/03/2001 – 02/07/2001Area = 134 778 m2

Total Loss = 239 319 m3

Expected to be dredged = 250 000 m3

GIS Analysis

Allows you to:

Quantify sedimentary volumes in transit;

calculate accretion and erosion rates;

interpretate the resulting of natural phenomena and

human intervention;

identify currents/sedimentary flows (and/or

hidrodynamic);

Predict sedimentary variations depending on the

same natural conditions.

Harbour entrance

Date (t1) 14-07-2000 27-07-2000 03-08-2000 28-08-2000 21-02-2001 06-04-2001 21-05-2001 29-08-2001Date (t2) 27-07-2000 03-08-2000 28-08-2000 21-02-2001 06-04-2001 21-05-2001 29-08-2001 21-11-2001Δt (days) 13 7 25 177 44 45 100 84

Average Height (m) 1,23 1,43 1,3 2,49 2,4 1,73 1,32 1,52

Average Direction (Deg. North)

280 292,14 297,8 297,2 286,24 304,56 306,1 281,01

Wave interval (s) 10,42 10,36 10,42 12,94 12,69 12,17 12,17 12,09

Loss Loss Loss Loss Gain Loss Loss Loss

Dredging (m3/dia) 6903 6490 1775 693 974 4255 2467 2820

Predicted (m3/dia) 1867 -2290 140 622 3545 1501 1242 2306

Gain Loss Gain Gain Gain Gain Gain Gain

-514-71 2571 -2754 -1225Balance (m3/day) -5035 -8780 -1635

-10

-8

-6

-4

-2

0

2

4

6

8

14/07/0027/07/00

27/07/0003/08/00

03/08/0028/08/00

28/08/0021/02/01

21/02/0106/04/01

06/04/0121/05/01

21/05/0129/08/01

29/08/0121/11/01

Milh

ares

(m

3/d

ia)

Balanço sedimentar

Extracções

Polinómio (Extracções)

Polinómio (Balanço sedimentar)

AVERAGE DAILY DREDGING VS.

CALCULATED AVERAGE BALANCE WITH GIS (HARBOUR ENTRANCE)

Joao Mendes

M.Sc Geoscientist

msc thesis

Business

sedimentary flows

rates of sedimentary

sedimentary volumes

sedimentary prism

study of sedimentary

sedimentary removal

coastal area

beach profileschapter