Measuring Water Velocity and Streamflow in Open-water and Under Ice John Fulton and Steve Robinson U.S. Geological Survey Joe Ostrowski Middle Atlantic River Forecast Center National Weather Service Dapei Wang Water Survey of Canada

Overview Evolution of MethodsEvolution of Methods  Water Velocity  Streamflow Open-water and Ice-cover ProjectsOpen-water and Ice-cover Projects  Radar  Acoustics The ‘Real Story’ Behind Your Ice RecordThe ‘Real Story’ Behind Your Ice Record

Evolution of Methods

Current-meter methods Evolution of Methods Chapra (1997) umax

Evolution of Methods Secondary and vertical flow components develop due to side-wall effectsSecondary and vertical flow components develop due to side-wall effects u max may occur below the water surfaceu max may occur below the water surface Darcy, in Proc. Roy. Soc., A (1909) Therefore, we need an “alternative” velocity distribution equation USGS (1904)

Evolution of Methods Information Entropy (probability-based solution for characterizing the velocity distribution) “y-axis” contains u max

Evolution of Methods u avg =  u maxu avg =  u max Q = u avg AQ = u avg A  (M) is a measure of a streams “happy place” and does not change with  (M) is a measure of a streams “happy place” and does not change with  flow  velocity  stage  channel geometry  bed form and material  slope  alignment A significant amount of information can be derived from the maximum velocity

NWS Proof-of-Concept Study ADCPs Radar guns Rating Curve “Actual” Stream Flow Current-meter method

NWS Proof-of-Concept Study Open-water Steps … 1.y-axis  (M) 3.u max or u D 4.area 5.Q = u avg A = (  u max ) A Yen (1998)

NWS Proof-of-Concept Study Open-water Steps … 1.y-axis  (M) 3.u max or u D 4.area 5.Q = u avg A = (  u max ) A Yen (1998)

NWS Proof-of-Concept Study Open-water Steps … 1.y-axis  (M) 3.u max or u D 4.area 5.Q = u avg A = (  u max ) A Chiu and others (2001)

NWS Proof-of-Concept Study Open-water Steps … 1.y-axis  (M) 3.u max or u D 4.area 5.Q = u avg A = (  u max ) A Yen (1998)

NWS Proof-of-Concept Study Open-water Steps … 1.y-axis  (M) 3.u max or u D 4.area 5.Q = u avg A = (  u max ) A Yen (1998)

NWS Proof-of-Concept Study Open-water Discharge methods Current-meter = 210 cfs Rating curve= 189 cfs Entropy regress = 193 cfs Entropy surf vel = 201 cfs s.d. = 9 cfs  = 0.58 u surf velocity – ADV = 2.6 fps u surf velocity – radar = fps Open-water Chartiers Creek at Carnegie, Pa Drainage area – 257 mi 2 Unregulated system

NWS Proof-of-Concept Study Open-water Discharge methods Current-meter = 10,800 cfs ADCP= 10,130 cfs Rating curve= 10,550 cfs Entropy regress = 10,330 cfs Entropy surf vel = 9,950 cfs s.d. = 340 cfs  = 0.78 u surf velocity – ADV = 2.4 fps u surf velocity – radar = fps Susquehanna River at Bloomsburg, Pa Drainage area – 10,560 mi 2 Regulated system

NWS Proof-of-Concept Study Open-water Open-water Basin DAs – 260 to 24,100 mi 2 Regulated and non-regulated systems

NWS Proof-of-Concept Study Ice-cover Steps … 1.y-axis and  (M) established during open water 2.u max along y-axis 3.area 4.Q = u avg A = (  u max ) A

NWS Proof-of-Concept Study Ice-cover Red River of the North at Grand Forks, ND (1984 to 2002)Red River of the North at Grand Forks, ND (1984 to 2002) Open water measurementsOpen water measurements Ice measurements were collected by the North Dakota District onIce measurements were collected by the North Dakota District on  01/20/04  02/05/04  03/02/04  =.596 computed for open- water used to calculate stream flow under ice cover  =.596 computed for open- water used to calculate stream flow under ice cover STA 84 Q act = 463 cfs Q obs = 476 cfs diff = 3% Nolan, K.M. and Jacobson, Jake, Discharge measurements under ice cover, USGS WRIR

NWS Proof-of-Concept Study Future Efforts … Partnering with thePartnering with the  NWS  SRBC  HIF  University of Washington  USGS, North Dakota District  Water Survey of Canada Wind and precipitation influencesWind and precipitation influences Flashy conditionsFlashy conditions Ice conditionsIce conditions Real-time areasReal-time areas

Project Scope EquipmentEquipment  SonTek Argonaut-SW & SL Open-channel flow and flow under iceOpen-channel flow and flow under ice Flow velocity distribution (FVD) modelFlow velocity distribution (FVD) model Water Survey of Canada

Vertical velocity distribution in open water  universal-velocity-distribution law  bed roughness parameter y0b to reflect effects of channel bed roughness  hydraulic parameter  to reflect effects of hydraulic gradient Water Survey of Canada

Vertical velocity distribution under ice cover ice roughness parameter y0i ice roughness parameter y0i for effects of bottom surface for effects of bottom surface of ice cover of ice cover approximated by a two-layer approximated by a two-layer scheme scheme lower layer - solely affected lower layer - solely affected by bed roughness by bed roughness upper layer - solely affected upper layer - solely affected by ice roughness by ice roughness Water Survey of Canada

ADVM SonTek Chateauguay River  Chateauguay River, QC, Canada  two SW installations, 400 m apart  SW data: Dec. 03 – May 04 Open flows & Flow under ice cover  upstream site: flow depth 2-5 m channel width ~ 85 m ice cover 12/11/03 to 3/25/04 21:30  downstream site: flow depth 2-4 m channel width ~ 40 m ice cover 1/9/04 9:45 to 3/4 12:00 Water Survey of Canada