As part of their irrigation strategy, the government and non‐governmental organizations (NGOs) in Malawi are actively promoting the use of treadle pumps in smallholder irrigation. The positive impact of treadle pumps on food security and poverty reduction in Malawi and elsewhere in sub‐Saharan Africa is well documented. However, few studies have analysed the adoption dynamics and dissemination approaches of treadle pumps. This study uses a logit model to analyse the factors influencing treadle pump adoption among a stratified random sample of 100 adopters and 100 non‐adopters in two districts in Malawi. The results indicate that relatively well‐off farmers have a significantly higher probability of adopting the treadle pumps than poor farmers. This raises questions about dissemination approaches and targeting, because treadle pumps are typically geared towards poor smallholders. The study further indicates differences between male and female adopters. Female adopters are more likely to pay for subsidized treadle pumps in cash. Male adopters mostly acquire their pumps through a loan. Women tend to spend the additional income on food for the household while men tend to spend it mostly on non‐food items. It is therefore likely that treadle pump adoption by women will positively impact on household food security, though it also adds to women's workload. Copyright © 2012 John Wiley & Sons, Ltd.

The expansion of irrigation in Sub-Saharan Africa has been slow. In Asia, the rapid expansion of smallholder irrigation systems was attributed in part to the availability and affordability of motorized pumps. This paper appraises the current extent of pump-based irrigation in Sub-Saharan Africa; profiles the socio-economic and demographic attributes of current pump adopters; and assesses the poverty outreach of small-pump technology. It shows that private smallholder irrigation is practised mainly by the wealthier farmers. The development of groundwater irrigation requires targeted and deliberate public-policy interventions and institutional support focusing on the more marginal farmers

The Aba'ala spate irrigation systems, traditional and modern, have experienced different set of floodwater and sediment management problems. Despite the dire need of alternative spate irrigation system layout, operational strategy and locally maintainable structures, efforts made to manage floodwater and control sedimentation had been structural. Hence, the study was conducted to evaluate the existing flood and sediment management practices and identify alternative options for optimum management of floods and sediments in Aba'ala plain. Primary data including discharge, sediments and river cross-sections were collected through direct field measurement. Interviews and focal group discussions were also employed to understand the operational and maintenance activities. Delft3D model was used to simulate flow and sedimentation under different scenarios. For the existing condition, the model showed high sediment deposition and low flood water abstraction. The floodwater diverted is 2.1 and 1.16 Mm 3 from the traditional intake and 1.52 and 0.51 Mm 3 from the modern intake at medium and low floods respectively which is far below the required 2.8 Mm 3 of water. Under Scenario-II, the modern intake diversion capacity is improved to 5.38 and 2.36 Mm 3 at medium and low floods. However, a water level decline of 15 cm is observed at Water Resour Manage (2015) 29:833-847 the downstream traditional intake which could be a cause for conflict between upstream and downstream users. Under Scenario-III, the diversion capacity of the modern intake is increased to 6.23 and 2.67 Mm 3 at medium and low floods respectively. Moreover, no decline in water level is shown at the downstream intake.

Farmers in flood-based irrigation systems face great uncertainties with respect to water supply. Using the Source-Pathways-Receptor and Consequence (SPRC) framework, this paper explores the sources of risks, propagation pathways, risk perceptions and consequences for the farmers, water users' associations (WUAs) and water managers in the Gash Agricultural Scheme in Sudan. The main source of risk is the extreme variability of rainfall, causing unpredictable flows regarding volume, timing and duration. The farmers, WUAs and system managers perceive the risks from floods differently. The farmers are primarily concerned by low floods, while the WUAs are more disturbed by untimely floods. The system managers are most troubled by high and potentially destructive floods. The poor state of the infrastructure, lack of proper maintenance and suboptimal operation aggravate the consequences of unpredictable flows. Consequently, the result is low and highly variable crop production. Besides paying attention to infrastructure improvement and regular operation and maintenance activities, more efforts in institutional arrangements and policy support could play an important role in coping with the risks indicated. The SPRC appeared to be a useful framework for analysing risks at different spatial scales and for different stakeholders in the spate irrigation system studied. RÉSUMÉLes agriculteurs dans les systèmes d'irrigation basés sur les inondations font face à de grandes incertitudes en ce qui concerne l'approvisionnement en eau. Utilisant la méthode Source-Voies-Récepteurs et Conséquences (SPRC), cet article explore les sources de risques, les voies de propagation, les perceptions des risques et les conséquences pour les agriculteurs, les associations d'usagers de l'eau (AUE) et les gestionnaires de l'eau du système agricole du Gash, au Soudan. La principale source de risque est l'extrême variabilité de la pluviométrie, qui entraîne des flux imprévisibles en termes de volume, de calendrier et de durée. Les agriculteurs, les AUE et les gestionnaires de système perçoivent différemment les risques liés aux inondations. Les agriculteurs sont principalement préoccupés par les faibles inondations, tandis que les AUE sont plus perturbées par les inondations intempestives. Les gestionnaires de systèmes sont les plus troublés par des inondations élevées et potentiellement destructrices. Le mauvais état des infrastructures, le manque d'entretien et le fonctionnement sous-optimal aggravent les conséquences des flux imprévisibles et entrainent une production agricole faible et très variable. Outre l'attention portée à l'amélioration des infrastructures et aux activités régulières d'exploitation et de maintenance, des efforts supplémentaires en matière d'arrangements institutionnels et de soutien aux politiques pourraient jouer un rôle important dans la gestion des risques. Le SPRC est apparu comme un cadre utile pour analyser les risques à différentes échelles spatiales et pour différentes parties prenantes dans le système d'irrigation p...

Conventional irrigation performance assessments narrowly confine the possible effects of using drip irrigation to what it is designed to do, i.e., improve efficiencies. While helpful in the design, such assessments leave little scope for the possibility that irrigators adopt the technology for reasons other than improving efficiencies. Using a case study about how irrigators in the farmer-managed Khrichfa Canal in Morocco engaged with drip irrigation, we propose a user-centred approach to irrigation performance. Use of this approach opens up the possibility that a technology is used and mobilized for other reasons than only those intended in the design process. (Résumé d'auteur

Excessive soil erosion hampers the functioning of many irrigation schemes throughout sub-Saharan Africa, increasing management difficulties and operation and maintenance costs. River water is often considered the main source of sedimentation, while overland sediment inflow is overlooked. From 2016 to 2018, participatory research was conducted to assess sediment influx in two irrigation schemes in Ethiopia. Sediment influx was simulated using the revised universal soil loss equation (RUSLE) and compared to the amount of sediment removed during desilting campaigns. The sediment deposition rate was 308 m3/km and 1087 m3/km, respectively, for the Arata-Chufa and Ketar schemes. Spatial soil losses amounts to up to 18 t/ha/yr for the Arata-Chufa scheme and 41 t/ha/yr for the Ketar scheme. Overland sediment inflow contribution was significantly high in the Ketar scheme accounting for 77% of the deposited sediment, while only 4% of the sedimentation at the Arata-Chufa scheme came from overland flow. Feeder canal length and the absence of canal banks increased the sedimentation rate, however, this was overlooked by the stakeholders. We conclude that overland sediment inflow is an often neglected component of canal sedimentation, and this is a major cause of excessive sedimentation and management problems in numerous irrigation schemes in sub-Saharan Africa.

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