Site ID: 249 Lat. 18.2891 Laos Vientiane
River: Nam Ngum Long. 102.5378
Site name: Tha Ngon Contributing area: 16139 km2 Ratio to Comparison Station: 0.03
Latest measurement: 29-Jul-10 Mean annual runoff: 675 mm (2003-2009)
Hydrologic status: 2 Normal flow Total runoff this year (2010): 398.6 mm
Latest M/C ratio: 1.32 Seven day total: 29.9 mm
Estimated current discharge: 882 m3/sec Percent of mean 7-day total: 129.9 % (today's value compared to mean for same period, 2003-2009)
Ice-cover determination: 5 yr recurrence flood: 2674 m3/sec (from Log Pearson III analysis)
Status Codes:  1 = Low flow or ice, 2 = Normal flow, 3 = Flood, 4 = Major Flood 2664 m3/sec (from Gumbel Extreme Value analysis)
Comparison Station Information:  Pakse (2469260)           Contributing Area:   sq mi 536010 sq km
(Data from this gaging station are used for the calibration to discharge, with an adjustment for different contributing areas)
Notes: Calibration to nearby ground station has not yet been accomplished.
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
146 2002 no data no data no data no data no data no data no data 69.6 47.6 10.0 8.7 9.7
228 2003 29.0 16.0 13.5 4.7 7.5 46.5 54.6 32.5 13.2 2.8 1.4 6.2
268 2004 20.4 16.9 6.4 2.5 1.2 63.8 66.7 43.9 39.3 1.7 0.7 4.5
878 2005 16.1 36.0 38.0 45.3 9.2 51.6 96.0 166.2 210.1 130.0 24.5 54.5
623 2006 81.9 56.8 80.8 23.3 51.8 77.5 67.4 75.5 74.3 33.3 0.0 0.0
654 2007 111.0 63.2 45.0 30.6 49.0 59.9 62.2 31.1 67.4 45.8 37.2 51.1
1264 2008 103.6 100.1 67.2 29.5 40.0 64.6 141.1 353.0 109.3 102.9 69.2 83.9
810 2009 126.3 83.9 62.3 13.7 20.4 105.5 104.5 115.8 51.9 29.4 30.7 65.7
399 2010 94.4 70.5 36.6 43.5 31.0 22.6 96.3 3.8 0.0 0.0 0.0 0.0
Mean Annual Runoff (mm): 675 Standard Deviation: 6.4
Trend in Annual Runoff (slope):  5.9
Discharge is estimated via a rating equation directly from the remote sensing data (M/C ratio) shown below.
Explanation:   Green line records upwelling microwave emission from within 5 km radius of a calbration land target; blue line is emission from within 5 km radious of the measurement target centered over the river.
Brown line is their ratio (M/C; scale on right) and is used to estimate river discharge via a rating equation.
Rating equations are being developed and applied on an individual basis. For calibration status, see "notes" entry, above.
GoogleEarth View of Measurement Site
Return
Estimated
Disharge
Data
Date m3/sec
22-Jul-02 3
23-Jul-02 3
24-Jul-02 3
25-Jul-02 3
26-Jul-02 332
27-Jul-02 350
28-Jul-02 223
29-Jul-02 198
30-Jul-02 265
31-Jul-02 146
1-Aug-02 146
2-Aug-02
3-Aug-02
4-Aug-02
5-Aug-02
6-Aug-02
7-Aug-02
8-Aug-02
9-Aug-02 1647
10-Aug-02 1647
11-Aug-02 1318
12-Aug-02 1072
13-Aug-02 805
14-Aug-02 640
15-Aug-02 482
16-Aug-02 428
17-Aug-02 428
18-Aug-02 240
19-Aug-02 250
20-Aug-02 267
21-Aug-02 430
22-Aug-02 592
23-Aug-02 629
24-Aug-02 665
25-Aug-02 471
26-Aug-02 471
27-Aug-02 338
28-Aug-02 3
29-Aug-02 3
30-Aug-02 13
31-Aug-02 3
1-Sep-02 1309
2-Sep-02 1309
3-Sep-02 914
4-Sep-02 782
5-Sep-02 302
6-Sep-02 391
7-Sep-02 472
8-Sep-02 372
9-Sep-02 450
10-Sep-02 309
11-Sep-02 309
12-Sep-02 55
13-Sep-02 55
14-Sep-02 3
15-Sep-02 3
16-Sep-02
17-Sep-02
18-Sep-02
19-Sep-02
20-Sep-02
21-Sep-02 239
22-Sep-02 241
23-Sep-02 241
24-Sep-02 249
25-Sep-02 254
26-Sep-02 312
27-Sep-02 312
28-Sep-02 3
29-Sep-02 3
30-Sep-02 3
1-Oct-02 3
2-Oct-02 3
3-Oct-02 136
4-Oct-02 136
5-Oct-02 277
6-Oct-02 241
7-Oct-02 93
8-Oct-02 146
9-Oct-02 122
10-Oct-02 84
11-Oct-02 169
12-Oct-02 3
13-Oct-02 3
14-Oct-02 3
15-Oct-02 6
16-Oct-02 51
17-Oct-02 80
18-Oct-02 97
19-Oct-02 87
20-Oct-02 87
21-Oct-02 3
22-Oct-02 3
23-Oct-02 3
24-Oct-02 3
25-Oct-02 3
26-Oct-02 3
27-Oct-02 3
28-Oct-02 3
29-Oct-02 3
30-Oct-02 3
31-Oct-02 3
1-Nov-02 3
2-Nov-02 18
3-Nov-02 210
4-Nov-02 329
5-Nov-02 329
6-Nov-02 156
7-Nov-02 167
8-Nov-02 76
9-Nov-02 23
10-Nov-02 3
11-Nov-02 3
12-Nov-02 3
13-Nov-02 3
14-Nov-02 3
15-Nov-02 3
16-Nov-02 3
17-Nov-02 3
18-Nov-02 3
19-Nov-02 3
20-Nov-02 113
21-Nov-02 113
22-Nov-02 28
23-Nov-02 3
24-Nov-02 3
25-Nov-02 3
26-Nov-02 3
27-Nov-02 3
28-Nov-02 3
29-Nov-02 3
30-Nov-02 3
1-Dec-02 3
2-Dec-02 3
3-Dec-02 3
4-Dec-02 3
5-Dec-02 3
6-Dec-02 3
7-Dec-02 3
8-Dec-02 3
9-Dec-02 3
10-Dec-02 3
11-Dec-02 3
12-Dec-02 9
13-Dec-02 3
14-Dec-02 17
15-Dec-02 126
16-Dec-02 126
17-Dec-02 10
18-Dec-02 121
19-Dec-02 73
20-Dec-02 95
21-Dec-02 242
22-Dec-02 43
23-Dec-02 43
24-Dec-02 3
25-Dec-02 3
26-Dec-02 3
27-Dec-02 3
28-Dec-02 12
29-Dec-02 222
30-Dec-02 344
31-Dec-02 266
1-Jan-03 266
2-Jan-03 3
3-Jan-03 3
4-Jan-03 3
5-Jan-03 9
6-Jan-03 47
7-Jan-03 218
8-Jan-03 218
9-Jan-03 104
10-Jan-03 96
11-Jan-03 89
12-Jan-03 125
13-Jan-03 190
14-Jan-03 181
15-Jan-03 145
16-Jan-03 22
17-Jan-03 22
18-Jan-03 135
19-Jan-03 276
20-Jan-03 425
21-Jan-03 432
22-Jan-03 511
23-Jan-03 207
24-Jan-03 207
25-Jan-03 3
26-Jan-03 42
27-Jan-03 10
28-Jan-03 174
29-Jan-03 308
30-Jan-03 345
31-Jan-03 607
1-Feb-03 419
2-Feb-03 419
3-Feb-03 207
4-Feb-03 255
5-Feb-03 201
6-Feb-03 98
7-Feb-03 121
8-Feb-03 5
9-Feb-03 5
10-Feb-03 141
11-Feb-03 210
12-Feb-03 178
13-Feb-03 122
14-Feb-03 103
15-Feb-03 10
16-Feb-03 16
17-Feb-03 3
18-Feb-03 3
19-Feb-03 3
20-Feb-03 3
21-Feb-03 3
22-Feb-03 3
23-Feb-03 36
24-Feb-03 180
25-Feb-03 180
26-Feb-03 16
27-Feb-03 40
28-Feb-03 3
1-Mar-03 3
2-Mar-03 3
3-Mar-03 3
4-Mar-03 3
5-Mar-03 211
6-Mar-03 211
7-Mar-03 241
8-Mar-03 321
9-Mar-03 414
10-Mar-03 298
11-Mar-03 298
12-Mar-03 212
13-Mar-03 212
14-Mar-03 9
15-Mar-03 31
16-Mar-03 3
17-Mar-03 3
18-Mar-03 3
19-Mar-03 3
20-Mar-03 3
21-Mar-03 3
22-Mar-03 3
23-Mar-03 3
24-Mar-03 3
25-Mar-03 3
26-Mar-03 3
27-Mar-03 3
28-Mar-03 3
29-Mar-03 3
30-Mar-03 3
31-Mar-03 3
1-Apr-03 3
2-Apr-03 3
3-Apr-03 3
4-Apr-03 3
5-Apr-03 22
6-Apr-03 3
7-Apr-03 3
8-Apr-03 3
9-Apr-03 3
10-Apr-03 73
11-Apr-03 30
12-Apr-03 67
13-Apr-03 3