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Integrated water resource management (IWRM) research for mitigating drought and improving livelihoods within the Limpopo Basin Project 17. Research Thrust.
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Integrated water resource management (IWRM) research for mitigating drought and improving livelihoods within the Limpopo BasinProject 17
Research Thrust To build evidence that improving water management through the IWRM paradigm improves rural livelihoods at the scale of the water management intervention: • Field scale – farmers • Local catchment scale – communities, villages • Sub-basin scale – districts, provinces • Basin scale – transboundary
Research Areas • Improved understanding of water resources • Farmer field-based action research (agriculture) • Institutional Research
Rainfall-Runoff Modeling • Good simulation of runoff within catchments • SWAT (Soil Water Assessment Tool) model application in Olifants • Reduction in streamflow with inc. land cover • HBVx Model in Mzingwane • Interception an important process (56% in a dry season 2006/07, 32 % of rainfall in normal season 2007/08) • Stream flow driven by rapidly draining shallow groundwater • Rainfall and runoff analyses (Pettitt Test) - change to drier regime since 1980
Hydrogeological Studies • Small sand rivers • Limitations • Evaporation (< 100 km2 give few months supply) • Geology (seepage a stronger control than evap.) • Large systems (Lower Mzingwane) –WAFLEX Model • Alluvial aquifer can store up to 38million m3 of water • Additional 3600 ha of smallholder farms can be potentially irrigated with the water
Lower Mzingwane Max. smallholder irrigation from alluvial aquifers Current
WaterQuality • Challenges, esp. metal pollution • Mozambique: • Major problems with metals: Zn, Cu, Pb, Cd • Design of a monitoring network done • Zimbabwe • Gold panning - potential Hg pollution in rivers • Natural salinity in shallow groundwater • Cadmium risk • These studies and one from SA point to dangerous levels of Cd
Conservation Farming • Zimbabwe • planting basins, ripping, conventional spring and double ploughing • Basin tillage showed lowest runoff • Reduced runoff did not translate to highest yield under these conditions • Modeling indicates that basins perform better • Mozambique • Basin tillage showed significant yield increase compared to conventional tillage
Crop Water Productivity • Crop simulation modeling in SA and field studies in Zimbabwe • Increasing fertility (N) increases water productivity • Crop water productivity (returns/mm) • Use of the APSIM Model in simulating grain yield and crop water use • APSIM performed well
Rainwater Harvesting • Mozambique • Inventory showed 21% adoption of pits compared to flood recession, small dams and road runoff • Zimbabwe • Evaluation of rainwater harvesting technologies in the Mzingwane Catchment • Dead level contours perceived as most effective by farmers, but measurements?? • Soil type and resource status were important factors • South Africa • Chololo pits increased maize grain yield compared to conventional farming
Supplemental Irrigation • Rain fed vs supplemental irrigation in South Africa • Drought year moisture deficit during flowering stage was reduced • Supplementary irrigation raised yield from 0.6 to 2.0 t/ha
Soil Salinity Studies- Chokwe • Salinity management strategies in irrigation • Salinity reduces yield and hydrological processes play a role – potential to model the system?? • Scenario analysis to improve irrigation performance and efficiency
Models of Catchment Planning • Mzingwane Catchment Council • Changes in the structure of the model • Understanding the role of women • Outline plan, addressing weaknesses that were identified by PhD research • Water chemistry results being taken seriously • BUT, confusing messages on CA, dead level contours • MCC appreciates the work of Phase PN17 so far
Evaluating Stakeholder Participation • Water User level -Lowest to district/sub-catchment • Water access • Private, communal, generally poor access at user level • Institutional processes • ‘New’ institutions are a manifestation of negotiation processes by users • Outside intervention dictates the processes • Rights creation • Appropriative rights the most common form of creation • Communal rights do not mean much without a legitimate and acceptable enforcer
Institutional Mapping and Performance • Water resource management at the local level – Mzingwane • Identifying practices, linkages and weaknesses • CA and donor influence • Water resource planning • The importance of the culture based normative framework in water resources management • Approaches to planning for water resource – bottom up approach more relevant
MainstreamingCapacity Building (CB) • Outreach through capacity building in the communities and institutions • CB was not follow-up or not a later add-on to research • CB is mainstreamed: • Integrated into project from planning stage onwards • Involving all scientists • Involving farmers and management agencies
Capacity Building & Knowledge Outputs • 32 MSc students completed 2 in progress • 8 females, 25 NARES staff • PhD students: • One student has graduated • 3 more students likely to complete by Dec 2009 • 5 farmer groups supported • Publications: 24 articles, 12 chapters, 81 conf. papers • Workshops: 5 basin level, 8 catchment level workshops
Decision-Support: Integrative Modelling • Coupling models into a decision support tool - ICHSEA • ArcView 3.3 interface • SWAT output to PARCHED-THIRST, its output to OLYMPE • Uncertainty analysis in progress • Scenarios: full-scale additional irrigation, supplementary irrigation, different water sources • Strategic tool, not an operational tool
Constraints • Rainfall variability and drought • Staff turnover and brain drain • Politico-economic conditions in Zimbabwe • Budget constraints