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2. Scope and aims of the programme

It was agreed at the brainstorming session on 19 October 2001 that this report and the Programme should cover water-lifting technologies appropriate for irrigation of units up to about 30 hectares (ha). This is to include most of the range of smallholder farmers in West Africa, and the smaller village schemes, though most applications will involve less than 1 ha. Also included are any water-supply applications that may fall into a similar range of lifts and discharges.[1] They therefore do not cover water-lifting for larger irrigation schemes, such as the formal state-sponsored schemes, nor the ‘informal medium-sized irrigation schemes' of Ghana.

The scope of the Programme depends on what is meant by the word ‘appropriate' in this study's title. It is assumed that in this context it means that water-lifting technologies should be cost-effective, sustainable (technically, financially and socially) and replicable. To achieve these aims a water-lifting technology needs to be well matched to the local situation and to the application, i.e. to the job that needs to be done. Many of the problems with newly introduced technologies have been the result of bad matching, for instance using motorized pumpsets at much less than their design head and/or speed, or using the wrong sort of treadle pump. This report therefore starts with the concept of matching technologies to applications and situations. The matching is between the supply side and the demand side of water-lifting, as shown in Table 2.1; the supply side is represented by location-neutral technologies, and the demand side by location-specific applications and situations.

It is significant that the Programme is required to cover both applied research and technology uptake. Uptake means the process by which information is delivered in a useable form to the people who need it, in order that water-lifting technology may be well chosen, delivered, and maintained. This report therefore covers uptake promotion, training, communication and dissemination as well as research.

It is assumed that for this report's purposes West Africa comprises Benin, Burkina Faso, Cape Verde, Cote d'Ivoire, Gambia, Ghana, Guinea, Guinea Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone and Togo. The proposed Programme's outputs on the ‘supply' side would be useful for adjacent countries such as Chad and Cameroon, and to a considerable extent for the whole of Africa.

TABLE 2.1 Framework for consideration of appropriate water-lifting technologies

Supply side (Technology-specific) Technology: a water-lifting technology is characterized by the:
  • type of power source (human, animal, electric motor, petrol engine, diesel engine, solar, wind, etc.);
  • type of pump or lifting device (bucket, calabash, piston pump, diaphragm pump, progressive-cavity pump, close-coupled self-priming centrifugal pump, submersible pump, axial or mixed-flow pump, etc.);
  • delivery arrangements (water dropped into a channel or reservoir next to the pump, or delivered under pressure into a pipe);
  • resulting technical characteristics, such as the optimum discharge and head, energy-efficiency under these optimum conditions, and efficiency at non-optimum conditions;
  • equipment's reliability, robustness, ease of maintenance, familiarity (e.g. some gasoline engines are familiar to local mechanics because they are similar to those found on motorcycles);
  • typical costs: initial cost, fuel or energy consumption, maintenance and repair costs.
Demand side (Place-specific) Application, the job to be done: a specific water-lifting application is characterized by the:
  • static lift (the height of the delivery point location above the water source);
  • device delivery head, if any (the pressure needed after the delivery point, for delivering water to a higher or distant location, or to drive an irrigation delivery system such as sprinklers);
  • instantaneous discharge needed (litre/sec or m3/h) (often limited either by the source, such as a borehole that suffers excessive drawdown if pumped too fast, or by the destination, for example an irrigator with a hand-held hose moving through a crop);
  • water storage arrangements, if any (provision of a small tank downstream of the pump makes pumping hours and flow rates independent of those for distribution, also enabling the resting of boreholes);
  • total daily volume needed (instantaneous discharge x number of operating hours per day ... the hours per day may be constrained by the need to do other things, or by the stamina of the operator in the case of human-powered devices).
Situation: the relevant conditions in the particular location; for irrigation these include:
  • soil and land types (affects ease of construction of washbores or other sorts of borehole or well);
  • nearby water resources (rivers, alluvial plains with shallow groundwater, etc.); their relative scarcity, reliability, seasonality and accessibility;
  • size of landholdings and degree of fragmentation;
  • typical farm family situations: labour availability, other time and energy-consuming activities of family members, availability of hired labour;
  • existence or feasibility of sustainable and effective farmer groups for shared use of a pump;
  • availability of fuel for engine-driven pumps; seasonal shortages;
  • fiscal and economic regime (e.g. tax rates on different sorts of fuel or on imported equipment);
  • availability of credit or subsidy, how it is structured, strength of financial institutions;
  • the capacity of the user; degree of mechanical skill, financial situation, access to credit, etc.;
  • commercial conditions, presence of entrepreneurs, dealers, mechanical workshops, etc.;
  • the locally available technical backup for particular technologies (advice, spare parts, etc.).

At the brainstorming session on 19 October 2001, it was explicitly agreed that the following activities would be covered by the Programme:

To these were added later, because of their importance,

At a meeting at IFAD on 6 December 2001, the following two topics were agreed to be relevant to the programme:

Part of defining the scope of the Programme is to clarify some things it does not cover. The definition of situations in which water-lifting technology is used, as set out in Table 2.1, includes some relevant aspects such as soil and water resources, land tenure, farm family characteristics, or irrigation method. The Programme is not intended to include either research or uptake work on these topics. In particular, the following aspects, which were mentioned or suggested at the brainstorming meeting on 19 October 2001, are not within the scope of the Programme:

Whether or not the Programme should include direct development of technologies was not explicitly agreed at the brainstorming session, though it was not included in the list of proposed activities. This is discussed further at the end of Chapter 6.

[1] Some village schemes are larger than 30 ha; however they are often best operated as several pumping units of around 20 ha each.

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