The Division: Hydrology comprises four Subdivisions, viz. Hydrological Support Services, with two Sections, viz. Hydrometry and Maintenance, Surface Water Database Management, Hydrological Investigations and Surface Water Resources Management.

The objectives of the Division Hydrology are to assist the Government in the national and regional monitoring and management of surface water resources by:

1. Rendering the services of a national hydrological centre in the country by the collection, dissemination and publication of hydrological data;
2. Providing information and advice on the potential and the optimal utilization of surface water resources.
3. Providing information and advice on the on the development and safety of water abstraction and other works in rivers.

The Division carries out the following major functions on routine annual basis:

1. Collect, process, store, safekeep, disseminate and publish historic hydrological data.
   • Establish, operate and maintain hydrological gauging stations in Namibia and on the border rivers.
   • gather historic hydrological data by measuring rainfall, evaporation, surface water and sediment load;
   • process, store and supply hydrological data.
   
   
2. Collect in real-time surface water data and advise on related action,
   • collect information on flow in rivers and react by giving flood warning and advise on flood control,
   • assess and advise on the short-term status of the surface water resources of the country.
   
   
3. Assess and advise on the development and safety of water abstraction and other works in rivers.
   • carry out flood related investigations,
     • determine peak, volume and frequency of floods,
     • evaluate and comment on proposals for the erection of flood control structures and other works in rivers.
   • carry out runoff related investigations
     • determine generalized runoff calculations and produce maps
     • determine generalized sediment load estimation methods and produce maps,
     • evaluate and comment on proposals for the implementation of farm dams and other water retaining or abstraction works in rivers.
   
   
4. Quantify surface water resources, assess the potential and make recommendations regarding the optimal utilization for water supply and other purposes.
   • quantify surface water resources.
   • provide a technical input into the management and joint utilization of border rivers by co-basin states.
   • assess the potential of surface water resources as an input to prefeasibility and feasibility studies on their utilization.
   
   
5. Give advice regarding the feasibility of small surface water schemes in rural areas, especially with regards to site, capacity and lay-out, and the monitoring of inflow and sedimentation patterns for such dams.

• Hydrological monitoring (installations, equipoment and methods), in particular riverflows including telemetry transmission
• Hydrological databases (HYDSTRA)
• Semi-arid and arid hydrology, in particular flash floods in ephemeral rivers
• Flood monitoring, including remote sensing for weather, rainfall and riverflow modeling and for floodmapping
• Operational hydrology, including early flood warning and management
• Hydrological investigations
• Hydrological modeling and analyses
• River flow and flood protection hydraulics
• Systems analysis and DSS for water resources planning and management
• GIS and remote sensing in hydrology and water resources management
• Specialized hydrological techniques like isotope hydrology
• IWRM, in particular applied in basin management and joint international river systems

In our perspective, the RSSC should take as starting point the variability of hydrometeorological parameters in interaction with socio-economic and environmental changes at local (basin) level.

Climate change puts great emphasis on this interaction, in both directions, at global, world-wide scale. For Namibia, however, the expected magnitude and impact of climate change may be of a lesser magnitude than natural and human-influenced variability changes that are already occurring and may be even more marked in future.

See the attached longest available time series for rainfall respectively riverflow for Namibia. These show no systematic change in statistics (like mean or variance), but high annual variations and prolonged wetter or drier periods, that are the most important features for availability of water resources and that may have similar relevance for environmental and socio-economic impacts . It is important that scientific evaluations are done regarding:

• Characteristics like magnitude, duration, frequency
• Possible causes and early indicators
• Resulting benefits and adverse impacts
• Future forecasts and management (mitigation)

Most important is the study of the interaction with natural and human factors, in both directions (impact on and result of). For instance land use, as a factor both influencing and being influenced by local (basin) hydrometeorological conditions.

In our perspective, the RSSC should emphasize research in support of operational activities relevant to Namibia. The deliverables should be products, services and methods for other organizations, and not merely extensions or expansions of on-going research activities.

The RSSC should therefore support capacity building by providing support resources and by providing opportunities for staff in other organizations to carry out research in their operational fields, for instance by detachment or PG studies.

Specific project areas:

• Hydrometric monitoring equipment and methods - setting up test bench for equipment?
• Sediment transport in ephemeral and seasonal rivers and effect on environment
• Remote sensing and earth observations in hydrology
• Joint regional approach for floodwarning
• Floodmapping
• Nuclear techniques in hydrology
• River hydraulics and flood protection
• Effect of run-of-river hydro-power schemes with daily regulation on river flow régimes

Concepts that were given as early inputs for RSSC are in ANNEX . Concept proposals are available for:

• Integrated (hazard and exposure) flood mapping
• Measurement of sediment transport by bed profile scanning for Kavango River
• Namibia 'sensorweb' for remote-sensing based flood and hazard monitoring and information system

ADVANCED REMOTE SENSING APPLICATIONS FOR FLOODS, DROUGHTS AND WATER RESOURCES ASSESSMENT

In Namibia's semi-arid to arid conditions, climate variability is high and climate change models anticipate higher variability of hydro-meteorological extremes, both droughts and floods. The trend towards more extreme floods and catastrophic inundations has been observed in the perennial rivers on Namibia's northern border, in particular the Cuvelai, Okavango, Kwando/Chobe and Zambezi river systems. Sudden exceptional floods in 2008 and 2009, possibly as result of increased climate variability, caused emergency disaster conditions for the local population and infrastructural development, in terms of disruption of agricultural activities, damage to infrastructure, breaks in communication and induction of water-borne diseases like cholera and malaria.

In 2009, the floods in the Cuvelai were the highest in living memory, and in the Kavango and Zambezi rivers the highest in at least 40 years, and new hydrological conditions and drainage patterns developed. Large areas of dried out deltas, like the Cuvelai, and lakes, like the Etosha Pan and Lake Liambezi, suddenly got inundated, and fossil river links, like between Okavango, Kwando/Chobe and Zambezi rivers, were observed as active flow channels for the first time in recorded history.

This new hydrological situation has major and unknown environmental impacts and it will also hamper socio-economic development of Namibia, as most of its population makes a living from agriculture in these areas. At the same time, the potential for new activities like commercial fishing and tourism might develop.

Adequate mapping of these areas during periods of floods is required for both operational management in case of new floods and planning for the future, short-term contingency planning and long-term urban and land use zoning. With direct access and conventional mapping being virtually impossible, application of remote sensing scenery is the most appropriate technique. Research should aim at developing methods and assessing usefulness of remote sensing for effective mapping and monitoring of drainage patterns and inundations during floods:

• To map the new situation;
• To analyze the historic changes in drainage and flooding patterns;
• To set up operational management systems for future floods;
• To evaluate the effect on vegetation and land use;
• To asses the environmental impacts; and:
• To support future socio-economic planning in the area.

The remote sensing techniques applied need to be advanced beyond normal optical scenes, using radar and micro-wave sensors. Other applications of remote sensing for early warning will include:

• Telemetric stations for rainfall and riverflow
• Remote sensing to monitor weather, cloud and thunderstorm development (MeteoSat)
• Remote sensing to obtain areal rainfall estimates (ditto)
• Remote sensing to evaluate catchment conditions (soil saturation, pools)
• Flash flood alarm systems combing some of above
• Remote sensing to estimate upstream flows (Dartmouth system) for early warning (like telemetry stations)

Remote sensing is also an applicable method for many areas of water resources assessment and hydrological modeling, and for studies of interaction with land use and vegetation conditions also during droughts.

All the above areas of research need a regional approach as riverflows and floods originate in neighbouring countries, in particular Angola and Zambia, and as rivers run for long distances along Namibia's borders, in particular Kunene, Kavango, Kwando and Zambezi rivers.

WATER RESEARCH

Any research should also give attention to water research, including inter alia but note exclusively:

• Maintenance of river channels, conveyance canals and water basins: Excessive plant growth and sedimentation are blocking and reducing the capacity of both natural and man-made waterways and impoundments. New techniques and equipment, e.g. the Finnish Watermaster, should be investigated and prototype-tested for Namibian conditions.
• Monitoring of sediment transport in rivers
• Desalination of groundwater: Many areas in northern Namibia have shortage of safe water because the available groundwater is not of adequate quality. Techniques to make this water suitable for human consumption, or at least for stock drinking or gardening/irrigation should be investigated, both at large- and small-scale.
• Rainwater harvesting.
• Storage of water in sand, so-called "sand storage dams", an old technique in Namibia, which needs re-activation on a scientific basis.
• Control and eradication of invader bush and other alien vegetation (such as prosopis), which consumes excessive amounts of groundwater.
• Modeling of propagation of floodwaves, using computerized hydrodynamic software, with particular attention for flash floods on dry riverbeds.
• Water allocation modeling using dynamic programming and systems analysis software.
• Modeling of environmental water requirements and environmental flows.

• In-service practical training for students and new appointees
• Access to foreign funding and (paid) study leave for postgraduate studies
• Regular short technical courses in hydrology, GIS, remote sensing, DSS, hydraulics
• Support for basin mnagament and other IWRM activities at stakeholders' level

Our main input would not be at the advanced research level, but we would give relevant guidance what outputs (products, services, methods) would be relevant in hydrology and water resources. We would be able to:

• Provide data, information and experience input for project elaboration.
• Give guidance, support and feedback during development.
• Test and implement in practice.

We would be able to give support for:

• Field operations (land, water, air) and installations (construction, maintenance)
• IT hardware and software
  • Remote sensing: ERDAS
  • GIS: ArcGIS
  • Hydraulic modeling: MIKE11
  • Systems analysis: WRYM/WRPM