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transcript
Hydrological Modeling-CPWFV303th-05th july , 2012
Presented byFrank ANNOR, KNUST-TUDelftFOWE TAZEN, 2iE Foundation
SCIENCE WORKSHOP : Volta Basin Development Challenge of the CPWF
Annual reflection meeting
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Presentation Outline1. Background2. Methodology
i. Instrumentationii. Modeling
3. Initial Results4. Way forward
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Morphometric characteristics of Boura catchment
Surface area (km²) : 155.3Perimeter (m) : 59.6Compactness index : 1.34Mean elevation (m) : 300Specific elevation(m) : 37.24Mean slope (m/km) : 3.4%Global slope index(m/km) : 4
Morphometric characteristics of Binaba catchment
Surface area (km²): 11.8Perimeter (m) : 14.6Compactness index : 1.2Mean elevation (m) : 225Specific elevation (m) : 23.80Mean slope (m/km) : 0.35%Global slope index (m/km) : 6.9
Background
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Background× No hydrological monitoring
– Boura and Binaba watersheds are ungauged
• No records of streamflow, evaporation, water level etc
• Difficult to calibrate a hydrological model in the basin at a small watershed without these records
× Management (allocation) of water has not been streamlined especially for the dry season
Objectives Physical and hydrological
characterization of watersheds of both sites
Building of the monthly streamflow time series
Establish the water budget of each reservoir
Determine the heat balance of the reservoir
Model GW-SW interactions
Andes • Ganges • Limpopo • Mekong • Nile • Volta
2IE Developing a Hydrological model
(Yates, GIRARD & GR2M) Developing a water allocation
model using WEAP at a smaller watershed level (Boura and Binaba) using the water balance Water Use Other components of the water
balance i.e Runoff, P,ET, etc
TU-Delft Evaporation and seepage losses
in lakes in the Volta basin using water and heat balance
Detailed study in Binaba & (Boura?)
Regionalising for the basin using remote sensing (Images through the TIGER project)
Groundwater surface water interactions (natural Isotopes)
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Methodology
Andes • Ganges • Limpopo • Mekong • Nile • Volta
?
??
Water budget of the reservoir
Boura only
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Getting the water balance right ..1
Rain gauge Evaporation pan
gauge plates
Monitoring wellDTS
EC
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Getting the water balance right …2
Thalimedes
Rainfall Sampling
Water Sampling Points for Isotope analyses
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Modelling Diagnostic Analyses of
Users/Typologies(Uses)
Model Output from ZonAgri
Evaporation & Seepage Losses model output
Output from other
hydrological models
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Some initial results
Seasonal flows in Boura
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Ecou
lem
ent
moy
en m
ensu
el(m
m/m
ois)
Lame_GR2M Lame_Yates Lame_Girard
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Some initial results
Annual flows
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Some initial results
Maximum monthly flows per year
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1971
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2003
2005
2007
Ecou
lem
ents
max
ima
men
suel
s pa
r an
(mm
)GR2M Yates Girard
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Some initial results
Maximum monthly flows per year
Modèle GR2M Yates Girard
Lame écoulée annuelle moyenne (mm)
36.02 31.6 34.79
Lame écoulée annuelle médiane(mm) 34.21 28.4 35.3
Ecart-type (mm) 16.84 17.6 20.85
Coefficient Variation (%) 46.77 57.74 59.92
Coefficient d'écoulement annuel moyen (%)
3.94 4.66 5.56
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Some initial results
Isotope Analysis
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Some initial results
Binaba reservoir
0
5
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25
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35
0
100
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400
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700Water Temperature at bottom of lake
Date/Time
Tem
pera
ture
(oC)
Wat
er le
vel (
m)
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Way Forward
More data collectionCalibration and verification of models Scenario building (climate change, water uses, cropping pattern)
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Thank you for your attention