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A PRACTICAL FLOOD WARNING SYSTEM BASED ON RAINFALL THRESHOLD IN UNGAUGED BASINS

HidroGaia S.L.

G. Bruni(1), L. Pujol Reig(1), E. Ortiz(1), E. Cifres(2) and R. García-Bartual(2) (1) HidroGaia S.L., Valencia, Spain, (2) Universidad Politécnica de Valencia, Spain (eortiz@hidrogaia.com / Phone: +34961366072 / Fax: +34961366073)

Tecnología del Agua y el Medio Ambiente

Aim: The new methodology based on Martina et al., 2006 uses quantitative precipitation forecast related to critical rainfall threshold values, resulting in a straight forward alert system applicable by non-specialists or stakeholders. Rainfall thresholds are defined from cumulative storm rainfall which can generate a critical discharge at specific river sections. Application: The first application of the exposed methodology has been carried out in 14 ungauged basins, situated in Galicia-Costa, a northern region of Spain.

-4

AUTOREGRESIVE MODEL

MODIFIED BARTLETT-LEWIS MODEL

storm 1 duration > 4

Time without rain > 6

storm 2 duration = 4 0

160

SYNTHETIC TEMPERATURE

SYNTHETIC RAINFALL

Meta Gaussian distribution

1

140

40

14

[Kelly and Krzysztofowicz, 1997]

2

120

STORM SEPARATION

Temperatura (Cº)

10

8 6

4

25

BY AMC & DURATION

20 15 10

2

1

5001

10001

15001

20001

25001

30001

Tc

T2

3 Tc

4

80

T3

Tc

60

4

3

2

1

200 150

400 300

100 200

5

Qp

40

6

20

7

50

100

Volumen de lluvia acumulado

Caudal pico

8

0

5 0

T1

100

Rainfall [mm]

30

Flow [m3/s]

35

12

1

3

5

7

9

11

13

15

17

19

21

23

25

27

29

31

33

35

37

39

41

43

Time [hs]

0 1

5001

10001

15001

20001

25001

30001

Tiempo (horas) Tiempo (horas)

RAINFALL THRESHOLD CURVES 250

SIMULATED FLOWS 350

200 AMCI

Vacum [mm]

Caudal (m3/s)

300 250 200 150

150 AMCII

100 AMCIII

100

50 50 0 1

5001

10001

15001

20001

25001

0

30001

0

Tiempo (horas)

4

8

12

16

20

24

28

32

36

40

44

48

52

56

60

64

68

72

76

80

T [hs.]

CALENDAR: OCTOBER CALIBRATION / VALIDATION

1.00

SIMULATED AVERAGED SOIL MOISTURE 0.90

200 100

OBSERVED FLOWS SIMULATED FLOWS

Humedad (%)

160 140 120 100 80 60

0.80

90 80

0.70

70 0.60

60

AMC

180

Flowsl (m3/s)

Precipitación (mm)

Densidad de Probabilidad

x 10

50 40

0.40

AMCI

30

0

0 14/02/2006

1

24/02/2006

06/03/2006

Time (hs)

AMCIII

0.20

10

20

AMCII

0.30

20

40

0.50

5001

10001

15001

20001

25001

30001

0.10

16/03/2006

Tiempo (h)

0.00

0

100

200

300

400

500

30 DAYS ACUMULATED VOLUME [mm]

600

700


A PRACTICAL FLOOD WARNING SYSTEM BASED ON RAINFALL THRESHOLD IN UNGAUGED BASINS