Water Demand - Impetus

The GLOWA Volta Project:
An overview
Jens Liebe,
Charles Rodgers,
Nick van de Giesen
and
Paul L.G. Vlek

The Volta Basin:
Major Expansion Challenge of irrigated in the Volta
5005%
Basin for agriculture Water Resources
mm 2500 mm +++
Management
42%
• 400,000 km 2
• 6 riparian countries
• 20+ million inhabitants
• 1,000 mm avg. precipitation
potential evaporation
Demand for irrigation
4%
6%
3%
40%
Hydropower generation
at Akosombo
Population growth rate:
Burkina Faso 3%
Ghana 2%
2000 mm 1500 mm +

Objectives
• Integrated analysis of the physical and social
determinants of the hydrological cycle
• Scientifically sound Decision Support System for the
assessment, sustainable use and development of the
water resources of the Volta Basin
• Development of “Human Capital“ via advanced education
and training, co-operative research and stakeholder participation

Climate, Land Use, Hydrology
Economics, Institutions, Stakeholders
Environmental
Remote
Sensing
Instrumentation
Land Conversion
Change
Water
Supply
Hydrology
Field
Investigations
Water Demand
Stakeholder
Dialogue,
Processes of decision
making and information
flows
Knowledge
Exchange,
Capacity
Building
Institutional
Analysis
Institutional Analysis
Mesoscale Climate
Integrated Basin
Model

Env. Change – Water Supply – Water Demand – Stakeholders/Capacity – Decision Support
Climate Change
• Increase in Temperature (1.2-1.3 °C )
• Greater variability
• rainfall
• runoff
• greater frequency of extremes
• Regional floods and droughts
Onset of the rainy season
• Prolongation of the dry season
• ORS more variable, today up to 30 days
later than 40 years ago
• Increase and intensification of rainfall
at the end of the rainy season
Precipitation Change [%]

Env. Change – Water Supply – Water Demand – Stakeholders/Capacity – Decision Support
Groundwater
production
Groundwater in the Volta Basin
• in White Volta Basin: annual
recharge 5-8% of annual rainfall
• GW use in Upper East Region of
Ghana ca. 5% of recharge
• Use below the potential

Env. Change – Water Supply – Water Demand – Stakeholders/Capacity – Decision Support
Surface Runoff Change [%]
Surface water in the Volta Basin
• Slight increase of river flow
• shift in runoff patterns
(later runoff generation)
• increase of extreme events
(floods and droughts)

Env. Change – Water Supply – Water Demand – Stakeholders/Capacity – Decision Support
Surface water:
Agricultural & hydropower
development
BURKINA FASO
Lery Reservoir
Volume: 0.6 km³
1976
MALI
Ziga Reservoir
Volume: 0.2 km³
2000
B U R K I N A F A S O
NIGER
Bagre Reservoir
Volume: 1.7 km³
1992
Small Reservoirs
Volume: 0.6 km³
Tono Reservoir
Volume: 0.1 km³
1980
Kompienga Reservoir
Volume: 2.0 km³
1984
BENIN
GHANA
Bui Reservoir
Volume: 12.3
km³
2009/2010
IVORY COAST
lake
Volta
TOGO
Lake Volta
Volume: 148 km³
1964
Small Reservoirs
Volume: 0.1 km³
G H A N A
Kpong Reservoir
Volume: 0.2 km³
1982

MIKE Basin Setup
1. 23 hydro-economic catchments for the Volta
Basin (specific discharge time series are
generated for each catchment) according to
national boundaries and large reservoirs.
2. large reservoirs: Akosombo, Bagre, Kompienga,
Ziga, (Bui), including hydropower and large
reservoir abstractions for irrigation and
portable water.
Area [km^2]
Volume [10^6m^3]
Area, Volume
3000
2000
1000
0
215 220 225 230 235 240
3. water user (sector) per catchment:
domestic use
industrial use
small scale irrigation (small reservoirs)
Water demand
[m^3/s]
Deficit carry-over fraction [()]
Groundwater use fraction [()]
Groundwater use absolute [m^3/s]
Elevation [m asl]
abstraction
60
40
20
0
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
year

Env. Change – Water Supply – Water Demand – Stakeholders/Capacity – Decision Support
Domestic water demand
Agricultural water demand
Water demand for hydropower
Urban Energy demand, Ghana
Rural
Burkina Faso
Ghana
Industrial water demand
Burkina Faso
Urban
Rural
Ghana

M³ WATER hydro-economic model
Multi-country Multi-sector Multi-use
COUNTRIES:
SECTORS:
USES:
Ghana / Burkina Faso
Agriculture / Domestic / Industry / Hydropower
(Non) - Consumptive / Environmental
W ater
A llocation
T echnology for the
E fficient management of
R esources in the Volta Basin

M³ WATER MODEL STRUCTURE
simulated specific discharge
g
time series (MM5/WaSiM-ETH)
5//WaSiM-ETH)
water supply
ply
transformation
tio
on
Hydrological HgHydrolog Hgical Hg
model
(MIKE Basin)
Hg
Optimization:
Allocation of water resources that maximizes
the total net benefits to society.
Economic model
(GAMS)
transformation
ti
on
water demand
demographic and economic indices
water use policies
simulated i l t d areal l precipitation p
it ti and d
potential potrapotenpotrapoten
evapotranspiration
p
potransspiration
(MM5/WaSiM-ETH)
pote
5 M

The Climate Generator
High-resolution Regional Climate and Hydrological Modelling for the Volta Basin of
West Africa (Harald Kunstmann and Gerlinde Jung, IMK-IFU, Garmisch-
Partenkirchen, Germany)
• Two time slices (1991-2000 and 2030-2039) of the ECHAM4 scenario IS92a were
dynamically downscaled with MM5 to a spatial resolution of 9 km x 9 km.
• The distributed process-based hydrological model WASIM-ETH was run with the
MM5 generated climate data for the time slices 1991-2000 and 2030-2039 with a
1 km x 1km resolution.

• expansion of irrigated agriculture
• increase in fertilizer use
• self sufficiency in rice

Example: Expansion of irrigated agriculture

Env. Change – Water Supply – Water Demand – Stakeholders/Capacity – Decision Support
Capacity building
• capacity building
• students
• networking
• workshops
• Volta Basin Authority

Env. Change – Water Supply – Water Demand – Stakeholders/Capacity – Decision Support
Example GVP Geoportal
Data search
– find and assess
– download
Interactive geodata
compose, view and
analyze on map
download from map
Publish and share data
index and administrate
assign use rights
upload for distribution

Services

Hydro Argos stations are linked to the GLOWA Volta Geoportal
Lawra
Chache
Yarugu
Pwalugu
Sabari

Decision Support
Decision Support Systems
Decision Support Tools
Decision Support
Characteristics of DST’s/DSS’s
• Foster understanding and assist decision making
• Link decision making, scientific information, and analytical tools
• Help experts to model the expected outcomes of certain actions
• Decision support tools solution tool
• Still require experts
In the Volta Basin: attain consensus/avoid conflict over
water allocation, respecting each
countries policy and development goals

Scales addressed in GVP Decision Support
West Africa Volta Basin Regional Local Independent
MM5
Geoportal
Joint Climate-Hydrology Simulation
Geodatabase
Prediction: Onset of the Rainy Season
Weather forecast
M³ Hydro-Economic Model
Soil moisture model
Institutional Map
Land Cover Change/LUCC detection
Agent based Energy & Land Use Model
Groundwater Recharge
Reservoir storage
Evaporation (Makkink, SEBAL, EC)
RS based runoff
GV-LUDAS
www.glowa-volta.de
LAMPT
Knowledge M’ment
Workshops/Training
Capacity Development and Network building

Conclusions
• Research networks have formed, capacity building was successful
• Data scarcity is reduced
• Environmental change leads to greater variability in precipitation, runoff
• Population growth leads to increased demand, competition for water
• GVP provides Decisions Support Resources at different levels
• GVP supports the Volta Basin Authority