Small reservoirs: hot spot of scattered resources in

the Volta basin

P. CECCHI

On behalf of the V3 Project

Burkina FasoLocalization

Enclosed within the large ring of the Niger River274 200 Km2 (≈ ½ France; ≈ 22% South Africa)10,5 M. inhbts in 1996 (14,1 M. in 2006)≈ 38 inhbts / km2 ; recurrent povertyUpper Basins of the Volta River (Ghana)

1951-1980

1981-2000600 mm

900 mm

1/ Threshold ≈ mid-seventies2/ Precipitations: - 30 %3/ Southern migration: > 100 km

SR: an answer toaridification

1951-1980

> 1700 reservoirs

SR ≈ 7 M. rural folk

Dry season:> 1000 km2

> 4000 km

Uses require water (quantity and quality)Uses impact the resource (quantity and quality)There exist trade-off between impacts and requirementsThat determine the nature of available resources

Water Uses and Users

Requirements

ResourcesResources

Impacts

Key wordsIntegrated managements

Processes studiesLocal scale

CPWF2: V3

Selection of key questions to be answered:

Erosion & siltation

• Why? Where? How? • What to do?

– Agricultural practices– Landscape management– Buffer areas– Context of climate change

(rain events frequency & intensity)

CPWF2: V3

Selection of key questions to be answered:

Water quality & productivity

• Agricultural intensification• Pesticides: origin & impacts• Eutrophication & Cyanobacteria: determinism• Health impacts• Bio-indicators: definition• Fisheries: development & limitations

CPWF2: V3

Selection of key questions to be answered:

Conflicts & access to (land & water) resources

• Ownership• New stakeholders• Agro-business & market• Decentralization• Rules? Equity?• Management & Governance

CPWF2: V3

From scale to scale

Up- & Down- scaling in termsof resource management

and/but also in terms of processes involved

CPWF2: V3

Main challenges

Real need of clarification of the (stakeholders) expectations- Political – Economical – Social – (…) VBDC

Importance of the participative approaches & modeling- Multidisciplinary diagnostics- Simulations PLATEFORMS

Assessment of the pertinence of the measured externalities- Economical- Hydrological CONSENSUS - Eco-health

Implementation of “pilot” operations METHODOLOGY

Up- and Out- scaling SHARING

CPWF2: V3