Site ID: 497 Lat. 35.9108 USA Arkansas
River: Black Long. -91.1915
Site name: Elgin Ferry Contributing area: 21422 km2 Ratio to Comparison Station: 0.92
Latest measurement: 5-Dec-09 Mean annual runoff: 958 mm (2003-2007)
Hydrologic status: 2 Normal flow Total runoff this year: 1325 mm
Latest M/C ratio: 1.31 Seven day total: 1 mm
Estimated current discharge: 824 m3/sec Percent of mean 7-day total: 140.0 % (today's value compared to mean for same period, 2003-2007)
Ice-cover determination: 5 yr recurrence flood: 4839 m3/sec (from Log Pearson III analysis)
Status Codes:  1 = Low flow, 2 = Normal flow, 3 = Flood, 4 = Major Flood 4737 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
246 2002 no data no data no data no data no data no data no data 1.8 15.9 13.4 67.4 148.0
1053 2003 109.7 135.2 130.7 88.9 280.2 50.2 4.9 1.0 3.6 15.0 69.2 164.3
1131 2004 140.2 99.1 128.6 101.9 220.9 51.5 8.5 0.4 0.8 40.2 159.5 179.4
1054 2005 274.0 159.9 110.9 110.5 44.7 55.3 2.6 2.9 7.5 1.0 117.6 167.3
576 2006 65.5 52.2 126.9 45.4 170.3 60.3 4.4 1.2 8.5 41.1 0.0 0.0
975 2007 283.2 121.7 97.1 82.9 174.8 38.0 7.5 0.5 5.6 18.9 26.3 119.1
1325 2008 87.0 114.5 325.5 468.9 208.4 23.7 22.4 0.4 0.7 0.4 12.4 60.6
1261 2009 44.8 123.1 120.0 125.2 299.9 89.7 47.1 8.7 9.1 79.8 287.2 26.2
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.
GoogleEarth View of Measurement Site
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