hydrological modelling of the ob river
Post on 22-Feb-2016
87 Views
Preview:
DESCRIPTION
TRANSCRIPT
Hydrological modelling of Hydrological modelling of the Ob riverthe Ob river
Sylvain BiancamariaSylvain Biancamaria(1)(1), Nelly Mognard, Nelly Mognard(1)(1), Paul Bates, Paul Bates(2)(2), Aaron , Aaron BooneBoone(3)(3) & Jean-François Cretaux & Jean-François Cretaux(1)(1)
(1) LEGOS, FR(2) University of Bristol, UK(3) CNRM/CNRS, FR
February 1st, 2008February 1st, 2008
Models usedModels used ISBA (Interaction Soil Biosphere Atmosphere) from ISBA (Interaction Soil Biosphere Atmosphere) from
CNRM (spatial resolution 1°x1°) for lateral inflows + CNRM (spatial resolution 1°x1°) for lateral inflows + LISFLOOD-FP, flood inundation model from University of LISFLOOD-FP, flood inundation model from University of Bristol, for the river :Bristol, for the river :
LISFLOOD
Flood plain topography
River centre, width and depth
Manning coefficients (friction) for river and
flood plain
Discharge, water depth and elevation (river & flood plain)
Discharge from Belogorje
gauging station
Incoming flow to the study domain
River modelling
TRIP
Lateral inflow to the river from study domainISBA
LSMRunoff from each pixel
Lateral inflow from the whole river basin
Atmospheric input
Lower Ob (between Belogorje and Salkhard):Lower Ob (between Belogorje and Salkhard):
Legend: Incoming flow (Belogorje) Lateral inflow (ISBA) River (CIA WDB) Gauging station
12
3
4
5
6
7
8
Time period: year 1993 (daily discharge at Belogorje only available from 01/01/1993 to 10/31/1994)
Study domainStudy domain
Comparison between modelled and measured discharge at Comparison between modelled and measured discharge at Salekhard as a function of the river depth (Manning Salekhard as a function of the river depth (Manning coefficient=0.015):coefficient=0.015):
Modelled dischargeModelled discharge
Discharge underestimation (~7000 m3/s) -> too weak lateral
inflow (linked with precipitation)
River depth=10m & Manning coefficient=0.015
River depth=15m & Manning coefficient=0.015
TopexVirtual station shown
Comparison between April and October 1993:Comparison between April and October 1993:Comparison Topex/modelled heightComparison Topex/modelled height
Orbit Parameters
Nadir/wide swath selection
Instrument ground location:
Water elevation:
Water elevation at the measurement
points
Instrumental Error(Gaussian noise)
Synthetic SWOT measurement
The synthetic SWOT measurement simulator developped by The synthetic SWOT measurement simulator developped by Noveltis for oceans has been adapted for hydrology:Noveltis for oceans has been adapted for hydrology:
SWOT simulatorSWOT simulator
Use of an Ensemble Kalman Filter to assimilate the synthetic SWOT observations into LISFLOOD.
Model uncertainties represented through an ensemble of model states, generated by perturbing: 1. Precipitation (rain+snow),2. Air temperature,3. River depth+flood plain topography,4. Manning coefficient.
Different Orbits can be tested. It will also be possible to assess how SWOT will improve the modelling compared to the use of only nadir data.
AssimilationAssimilation
top related