280 likes | 472 Views
A Field Trip to the Congo-- Hydroacoustic measurements in "the river that swallows all rivers". John Shelton South Carolina Water Science Center. Congo River Project. History with AMNH Field verification of model predictions (depth, slope, stream power, roughness, Froude)—WHY??
E N D
A Field Trip to the Congo--Hydroacoustic measurements in "the river that swallows all rivers" John Shelton South Carolina Water Science Center
Congo River Project • History with AMNH • Field verification of model predictions (depth, slope, stream power, roughness, Froude)—WHY?? • Acoustic and Water Quality measurement --Fish diversity definition --OSW time tests --Turbulence definition --QW field parameters and samples • --Bathymetry • --Discharge
Congo River is a major biogeographic barrier American Museum of Natural History
“...landlocked system was captured in the Miocene (5-15 mya) by a short river draining into the Atlantic Ocean, producing the drainage pattern of Central Africa seen today.” (Stankiewicz & de Wit, 2006) BUT others claim the capture event happened as recently as 400,000 ya (very young) while yet others claim it occurred as long ago as 35mya (very old) American Museum of Natural History
CURRENT SPECIES COUNT ca. 135 ~ 30% endemism American Museum of Natural History
Lamprologus werneri Lamprologus tigripictilis Lamprologus lethops American Museum of Natural History
Lamprologus lethops American Museum of Natural History
Field Verification and Hydroacoustic Measurements • 7-man kayak team • 80 mile reach • NGS Photo/ videography • Single line bathymetry
Kayak Team 2X • Differential GPS • Echo sounder • Power supply • Data logger • Kayak-cam • Helmet-cam • QW sampling supplies
Congo River at Luozi • 1.26 million CFS in 22 minutes • 1.3 miles wide • 80 feet deep
Processing Issues • Power • Power • Bugs
Water-quality monitor Solar Panel Differential GPS Echo sounder transducer 300 kHz ADCP Laptop Echo sounder Power supply
What IS the deepest river?? ADCP Beam Depth Echo Sounder Depth
Velocity Distribution--Relearned • Areas of significant down-welling • Downstream “jets” at depth
ADCP measurements: Lower Congo River 2008 • 6 random transects • Four surveys Ned Gardiner, PhD AMNH/NOAA
Below Bulu Ned Gardiner, PhD AMNH/NOAA
Turbulence Definition—Longitudinal transect • Accelerations in “constricted” areas • Velocity “ramps” and “dives” due to bedforms
Where do we go from here? • Primary data processing/interpretation • Relate hydraulic data to fish data • Visualization products --Animations, fact sheets, NG Explorer • Water-quality samples (nutrients, major cations, metals) • Future projects