Site ID: 2112 Lat. 23.3228 China Guangdong
River: Bei Long. 112.8676
Site name: Datang Contributing area: 39692 km2 Ratio to Comparison Station: 1.71
Latest measurement: 9-Jan-10 Mean annual runoff: 1845 mm (2003-2007)
Hydrologic status: 2 Normal flow Total runoff this year: 1957 mm
Latest M/C ratio: 1.55 Seven day total: 2 mm
Estimated current discharge: 1993 m3/sec Percent of mean 7-day total: 94.3 % (today's value compared to mean for same period, 2003-2007)
Ice-cover determination: 5 yr recurrence flood: 3795 m3/sec (from Log Pearson III analysis)
Status Codes:  1 = Low flow, 2 = Normal flow, 3 = Flood, 4 = Major Flood 3757 m3/sec (from Gumbel Extreme Value analysis)
Comparison Station Information:  Tokwe Confluence D/s C/s (1495240)       Contributing Area: 7280 sq mi 23237 sq km
(Data from this gaging station are used for the calibration to discharge, with an adjustment for different contributing areas)
Notes: Comparison station is placeholder, only; this site is not yet calibrated to actual discharge
Discharge and runoff, based on satellite remote sensing (NASA AMSR-E data)
(For U.S, sites, nearby ground station discharge may also be shown)
2008-Present
2002-Present
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
725 2002 no data no data no data no data no data no data no data 114.1 134.7 162.1 160.3 153.3
1886 2003 163.0 137.0 132.5 155.3 159.2 143.5 184.1 166.6 163.3 180.3 129.7 171.3
1909 2004 143.2 142.5 130.2 159.4 159.4 164.4 176.5 138.4 173.5 193.7 159.5 168.0
1893 2005 123.5 100.7 143.4 147.5 169.0 166.9 185.3 174.7 168.3 185.5 156.2 171.6
1585 2006 147.5 127.3 122.3 139.7 170.1 170.3 178.5 182.6 169.5 177.5 0.0 0.0
1950 2007 144.4 156.1 129.3 143.1 167.5 166.3 184.0 167.6 174.1 189.6 172.0 156.1
1957 2008 129.7 136.3 155.9 160.2 142.5 145.3 192.5 197.8 177.3 184.3 169.7 165.3
1930 2009 152.4 167.6 139.2 137.5 155.6 172.1 177.2 169.0 161.3 183.9 151.6 162.4
Discharge is estimated directly via a rating equation from the remote sensing data (M/C ratio) shown below.
Explanation:   Green line records upwelling microwave emission from a land parcel (ca 10 km x 10 km) near the river; blue line from a parcel 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.
When data above show calibration site values lower than for the measurement site, discharge estimation may not be possible.
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