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UIT GmbH Dresden • Germany 1.5D River Model for Radionuclide Transport & Accumulation H. Kalka More Info: Interim Technical Task Report 05 – EAP RU 06 – ITT05 (Task 5.1) May 30, 2007
UIT GmbH Dresden • Germany
1.5D River Model for Radionuclide Transport &
Accumulation
H. Kalka More Info:
Interim Technical Task Report 05 – EAP RU 06 – ITT05 (Task 5.1) May 30, 2007
EUROPEAID 121579/C/SV/RU: “Monitoring and Warning System for the Ob/Irtysh River Basin”, Service Contract 99310, funded by the European Union
ModelingRadionuclide Transport
Model Concept1Mathematical Model2
3 Software4 Input Data
5 Basic Scenario Studies
- 2 -Modeling --- May 2006
The Extraordinary Task
... requires a new approach.
Ob-Irtysh-Basin
- 3 -Modeling --- May 2006
River Basin
15
29 400
12 000
2 950 000
Ob-Irtysh
< 5% of MADReservoir Capacity
140 000m³/sFlood Discharge
100 000m³/sMean Annual Discharge (MAD)
2 200 000km²Drainage Basin Area
Amazon
model space discretization
- 4 -Modeling --- May 2006
C++
Modus Operandi
Conceptual Model
Mathematical Model dc/dt
Numerical Model ∆c/∆t
Software Database
River Model
- 5 -Modeling --- May 2006
Radionuclide Transfer
solute colloidal
river segments
wind erosion
flood-plain
flood-plain
flood-plain
flood-plain
wind erosion
(seasonal)
(perennial)
Transport
deeper deposits
bedsediment
bedsediment
bedsediment
bedsediment
- 6 -Modeling --- May 2006
Compartment Structure I
River System
River A River B River N
W
S
F
B
W
S
F
subcompartm
ents
solute
colloidal
floodplain sediment
river-bed sediment
Accumulation
Transport
B
- 7 -Modeling --- May 2006
contamination source junction of two rivers
Contamination SourceJunction of Two Rivers
Compartment Structure II
- 8 -Modeling --- May 2006
Radionuclide Transport
deep bottom layer
seddesorp
radionuclidesin solution
W
adsorp
desorpadsorped
radionuclideS
top layer B
adsorp res
deposit
suspendedsedim
ents
- 9 -Modeling --- May 2006
Mass & Concentrations
Wsus SVm =
)1(Vm sedSsed ε−ρ=
WCVM =
WSS SVCM ⋅=
sedBB mCM ⋅=
mass of suspended particles
mass of top-layer bed sediment
dissolved radionuclides
radionuclides adsorbed on colloids
radionuclides in bed sediment
Bq
Bq
Bq
kg
kg
FFF mCM ⋅=radionuclides in floodplains Bq
6 dynamical variables
- 10 -Modeling --- May 2006
Submodels (SM)
Water Flow SM v , Q
Sediment Transport SM S
Radionuclide Transport SM C , CS , CB
Inundation / Floodplain SM CF
- 11 -Modeling --- May 2006
Water Flow Submodel
i − 1 i + 1i
QinMass
Con
serv
atio
n
Water Budget
Integration (∆x i)
inii1i1ii QQQ += →−+→
inqxQ
tA
=∂∂
+∂∂ A
Qv =
- 12 -Modeling --- May 2006
Sediment Transport
)SS(Aq
)ff(h1
xSAD
xA1
xSv
tS in
in
S −+−=⎭⎬⎫
⎩⎨⎧
∂∂
∂∂
−∂∂
+∂∂
↓↑
)ff(h
Vt
m Wsed
↓↑ −−=∂
∂
resuspension
dispersion
sedimentation
inflow
- 13 -Modeling --- May 2006
Radionuclide Transport
S)CC(AqC
xCAD
xA1
xCv
tC
adsin
in
Γ−−+λ−=⎭⎬⎫
⎩⎨⎧
∂∂
∂∂
−∂∂
+∂∂
↑−+Γ+−+λ−=⎭⎬⎫
⎩⎨⎧
∂∂
∂∂
−∂∂
+∂∂ f)CC(
hS1)CC(
ASSq
Cx
CADxA
1x
Cvt
C SBads
SSin
ininS
S
S
SS
sources
dispersion
advection
solute
colloidal
decay
- 14 -Modeling --- May 2006
Floodplains
t
Q
river channel
floodplains
non-flooding period during flooding
⎟⎟⎠
⎞⎜⎜⎝
⎛
⎭⎬⎫
⎩⎨⎧
−λ=F
F
R
FSF
F
QuAexp1
QQm
dtdm
- 15 -Modeling --- May 2006
Software in C++
Fast running model for scenario analysis
Modular design (OOP)
User-friendly graphical interface
Online- and offline graphics
interface to databases / warning systems
- 16 -Modeling --- May 2006
Generating Input Data
Model-Space Discretization
Hydrological Data
Initial Concentrations (t = 0)90Sr 137Cs
Geometrical / Global Data
j(t) in Bq/s
Radionuclide Sources
- 17 -Modeling --- May 2006
Geometrical Data
Segment length L m
Average channel width B m
Average water stage h m
Thickness of top-layer sediment Z m
Average sediment porosity ε m³/m³
Average particle density ρS kg/m³
Average floodplain area AF m2
- 18 -Modeling --- May 2006
Hydrological Data
qin m²/s
m³/s
S(t0) kg/m³
Q0 1Average inflow into 1st segment
Average lateral inflow
Initial colloid concentration
Non-flooding period
QF m³/s
SF kg/m³
Average flow
Average colloid concentration
Flooding period
- 19 -Modeling --- May 2006
Initial Concentrations (t=t0)
dissolved in river water C Bq/m³
adsorbed on colloids CS Bq/kg
in river-bed sediments (top layer) CB Bq/kg
in floodplain sediments CF Bq/kg
Radionuclides ( 90Sr, 137Cs )
- 20 -Modeling --- May 2006
Model Validation / Calibration
Non-Flooding
Water Flow / Water Budget1
Radionuclide Transport & Accumulation2
Flooding Period
- 21 -Modeling --- May 2006
Basic Scenarios (Examples)
since t0 = 1949“historical” reconstruction of actual state1
long-term behavior of current state2forecast without incidents
short-term after sudden natural events3flooding etc.
short-term after sudden incidents4failures of radionuclide reservoirs
- 22 -Modeling --- May 2006
Finally Remark
the proper implementation of the mainprocesses within the numerical model
The success of modelingdepends on ...
1
2 the quality of input data
complete time series of monitoring data
model calibration
