deborah ofori research scientist, surface water division
DESCRIPTION
Adaptive management of groundwater resources for small scale irrigation in sub-Saharan Africa (AMGRAF). Deborah Ofori Research Scientist, Surface Water Division. Mid-Year Review Seminar WRI Conference Room, 15 .07.2014. Outline. Project Information - PowerPoint PPT PresentationTRANSCRIPT
Adaptive management of groundwater resources for small scale irrigation in
sub-Saharan Africa (AMGRAF)
Deborah OforiResearch Scientist, Surface Water Division
Mid-Year Review SeminarWRI Conference Room, 15.07.2014
Outline
Project Information
Background/Introduction of AMGRAF
Baseline Study
Methodology
Progress of Study
Way Forward
Project Information
Unlocking the Potential for Groundwater for the Poor (UPGro)
Aims: To enable developing countries in SSA to use
groundwater in a sustainable way to benefit the poor
Project Information cont.Research Issues
Where GW, how and at what rate is it recharged, and how can it
be more effectively and efficiently abstracted to meet local
needs?
What is the state of the resource – quantity & quality; how will it
respond to abstraction, impact of growing population, climate
change, etc.?
What governance arrangements are needed to support this
access in an inclusive and sustainable way, and in particular to
reach the poorest and most marginalised groups?
Project Information cont.
Funding Natural Environment Research Council (NERC),
Economic & Social Research Council (ESRC) & Department for International Development (DFID)-UK
7-year international research programme - First Phase: Catalyst grant - Second Phase: Implementation of Main Project
Project Information cont.
AMGRAF - Catalyst grant (12 months)
WRI (Ghana) & CSIR (South Africa) – Baseline Studies & Consortium building
Ethiopia – Pilot study
Implementing PartnersCSIR- Water Research Institute, International Water Management Institute (Ethiopia), Geological Survey, Ethiopia, CSIR (South Africa)
Project Information cont.
Aim: To enable sustainable development of accessible
(shallow) groundwater for small-scale irrigation in sub-
Saharan Africa
Concept: is that ‘accessibility’ is more important than
aquifer potential
Working definition: Depth to groundwater should be
less than 25 meters
AMGRAF Baseline Study Title Assessment of Shallow Groundwater Irrigation in the
Upper East Region of Ghana
Project TeamDr Emmanuel Obuobie (RS)Deborah Ofori (RS)Dr Emmanuel Obeng-Bekoe (RS)
Project Duration 1 Year (2013 –2014)
Introduction Study area: Upper East Region (UER) Land area: 8,842 km2 (4% of Ghana) Slope: < 2% Region is largely drained by the
White and Red Volta rivers
Introduction cont.
UER is located in the Sudan-savannah climate zone and can be described as semi-arid
Rainfall pattern is mono-modal with distinct wet (May-Sept/Oct) and dry (Nov-April)seasons
Rainfall is characterized by high temporal and spatial variability
Dry spells during rainy season Mounting evidence of Climate
variability and change GW offers a more food secure
alternative to rain-fed farming
Climate - UER
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec0
50
100
150
200
250
25
27
29
31
33
Precipitation Evapotranspiration Temperature
Month of YearPr
ecip
itatio
n/PE
T (m
m)
Tem
pera
ture
(oC)
Long-term mean rainfall, PET and temperature at Bolgatanga (UER)
Introduction cont.
Population in 2010 (GSS, 2012): 1,047,545 – 48 % males & 52% females
High population density (118 persons/km2) Settlement is largely rural (84% rural, 16% urban) &
large farming households (~ 6) Predominant occupation is small scale farming (84 %
of households)- GSS 2012 >80 % of population live below official poverty line
(GHC 90 or US $34) – GSS 2012 About 80% of population depend on GW for water
supply; GW for irrigation is limited
Demography & Socio-economic
Introduction cont.
Objectives Understand the characteristics of shallow
groundwater irrigation (SGI) Assessment of groundwater (shallow)
resources & characteristics Understand groundwater governance
structures and linkages at levels of management
Investigate socio-economic drivers for SGI
Methodology
Review of WRI work on groundwater Review of studies on shallow irrigation (IWMI
work & other studies) & groundwater assessment
Stakeholder consultation (Institutions, farmers, MOFA, etc.)
Progress of Study
Shallow groundwater Irrigation (SGI)
Resource Assessment
Shallow groundwater Irrigation
Major uses of groundwater in the UER SGI is categorized as informal irrigation, mainly
during dry season low-lying areas such as flood plains, alluvial
channels and valley bottoms where the water table is high
Manually tapped using simple tools & indigenous knowledge
Hand-dug wells usually less than 10 m deep
Shallow groundwater Irrigation cont.
Water is lifted & distributed using : rope and bucket/ container, &motorized pumps
Many farmers have 2 or more wells Farm sizes ranges between 0.01-0.5 ha Major Crops: tomatoes, onions, pepper, leafy
vegetables Farmers usually do not own the land; have
some arrangements with landowners that allow them to cultivate
Progress of Study cont.Resource Assessment 2 main geological formations: Precambrian crystalline
rocks & Paleozoic sedimentary consolidated rocks
L E G E N D
International BoundaryRegional BoundaryGeological Boundary
FORMATIONS
Buem VolcanicsBuem
Togo Series
Tarkwaian
Upper BirrimianLower Birrimian
Basic Intrusives
Granite
Obosum Supergroup
Damongo MassifGambaga Massif
11°
8°
9°
3°
10°
2° 1°
N
0° 1°
0 50 Km
Regional Capital
Tossiegou
Oti Beds
{
{ }
}
Resource Assessment cont.
3 main Aquifer zones: weathered zone, bedrock-weathered zone interface, fractured zone
Aquifer zones & types
Schematic representation of the hydrogeological profile in the Precambrian crystalline rock in the Upper East region (Obuobie et al., 2013)
Resource Assessment cont.
Borehole characteristics
Summary of borehole information in the Upper East Region (Agyekum et al., 2008)
District map of the Upper East Region (2008 map)
Based on data from 2,458 successful boreholes
Resource Assessment cont.Groundwater Recharge
Groundwater recharge for specific locations in Ghana (Obuobie and Barry, 2012)
Recharge is mainly through precipitation (direct & indirect) Contribution from regional aquifers is insignificant
Resource Assessment cont.Simulations by Models Obuobie & Ofori (2013):Huge potential for groundwater use in the Basin including the UER
Map of groundwater potential zones of Ghana (source: Gumma and Pavelic, 2012)
Groundwater development potential map of northern Ghana (source: Forkuor et al., 2013)
Resource Assessment cont.Groundwater quality Based on analysis of water samples from 214 boreholes
Summary of groundwater quality in the Upper East Region ( Amuzu, 1974 cited in Agyekum et al., 2008)
Socio-economic & Governance
Stakeholder consultation is underway
Way Forward
Complete the stakeholder consultation process
Understand the socio-economic drivers for shallow ground irrigation
Identify key issues, challenges & opportunities for GW resources & SGI
Identify knowledge and data gaps in groundwater resource assessment, etc.
Identify knowledge gap in groundwater governance
Thank You