1585

Lat.

-23.5589

Madagascar

Toliara

River:

Onilahy

Long.

44.3323

Site name:

Bezaha

Contributing area:

29452

km2

Ratio to Comparison Station:

0.54

Latest measurement:

15-Nov-09

Mean annual runoff:

383

(2003-2007)

Hydrologic status:

Low flow

Total runoff this year:

364

Latest M/C ratio:

1.00

Seven day total:

Estimated current discharge:

112

m3/sec

Percent of mean 7-day total:

102.9

(today's value compared to mean for same period, 2003-2007)

Ice-cover determination:

5 yr recurrence flood:

2230

m3/sec

(from Log Pearson III analysis)

Status Codes: 1 = Low flow, 2 = Normal flow, 3 = Flood, 4 = Major Flood

2122

m3/sec

(from Gumbel Extreme Value analysis)

Comparison Station Information:

Bevoay (1389090)

Contributing Area:

sq mi

54530

sq km

(Data from this gaging station are used for the calibration to discharge, with an adjustment for different contributing areas)

Notes:

Rating equation is based on comparison of monthly means from a station in the region

Discharge and runoff, based on satellite remote sensing (NASA AMSR-E data)

(For U.S, sites, nearby ground station discharge may also be shown)

Annual

Monthly Total Runoff (mm), computed from above satellite-based discharge data

Runoff

(mm)

Jan

Feb

Mar

April

May

June

July

Aug

Sept

Oct

Nov

Dec

2002

no data

11.7

11.8

11.0

10.2

15.5

312

2003

22.4

37.1

70.2

34.3

27.3

30.6

24.4

16.7

11.4

13.1

10.6

14.2

281

2004

18.4

29.6

65.9

23.0

22.1

23.1

25.1

22.5

17.2

12.1

10.1

12.2

437

2005

36.3

72.5

65.1

45.5

26.5

38.4

31.7

20.1

15.1

10.3

29.8

245

2006

25.8

24.1

45.5

34.7

25.6

28.6

21.1

16.2

12.0

11.6

0.0

641

2007

83.3

128.5

122.7

65.1

71.4

49.3

38.7

24.6

15.3

15.9

11.8

14.5

364

2008

36.7

31.2

40.9

48.8

37.5

31.7

32.8

24.6

16.5

13.9

15.2

34.4

391

2009

69.4

57.8

63.1

63.3

31.2

28.7

24.2

21.3

13.2

12.1

6.5

0.0

Mean Annual Runoff:

380

Standard Deviation:

144

Trend in Annual Runoff (slope)

32.82

Discharge is estimated directly via a rating equation from the remote sensing data (M/C ratio) shown below.