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This article examines trends in the understandingof and policies toward farmer participation in irrigationmanagement over the past 20 years, with special attention toexperiences with induced participation and management transferprograms in the Philippines, Sri Lanka, Pakistan, Senegal,Columbia Basin USA, and Mexico. Key lessons relate to the valueof social organizers as catalysts; the role of the irrigationagency as partner; and the enabling conditions for participation.As levels of income and infrastructure rise, we can expect moreformal organizations that enable farmers to deal with bankaccounts, service contracts, water rights, water markets, andadvanced technology in irrigation systems. The impact ofparticipation on irrigation performance needs to be evaluated notjust in terms of reductions in government costs, but by whetherimprovement in physical structures and farmers‘ control overwater are great enough to offset the farmers‘ costs ofparticipating.

Several field studies were conducted tobetter understand the influence of culturalpractices, inflow rate and field conditionson the performance of modern surfaceirrigation systems in Egypt. Field datawere collected on wheat and cotton underEgyptian conditions in order to estimateinfiltration, roughness and performanceparameters. Tests were made with a varietyof inflow rates and a variety ofcross-section shapes (flat or furrowed andseveral furrow spacings). These studiesprovide information on expected values ofinfiltration and roughness parameterstypical of cracking clay soils in the NileDelta, as well as guidelines andrecommendations for use of long-levelbasins in Egypt.

Mô hình giả lập SIDRA dựa trên một giải pháp nửa phân tích và nửa số cho phương trình Boussinesq. Mô hình này được phát triển dựa trên các kết quả lý thuyết và thực nghiệm thực địa với mục tiêu dự đoán chính xác cả lưu lượng đỉnh thoát nước và lưu lượng hồi phục. Các khía cạnh lý thuyết và các phương trình cơ bản của mô hình được trình bày cho trường hợp tổng quát nhất, nơi cả tính chất vật lý của đất và hình dạng mực nước đều phụ thuộc vào độ sâu. Độ nhạy của các tham số và hiệu suất thực địa của mô hình được ước lượng trong các loại đất thịt nông cạn đối mặt với tình trạng ngập nước mùa vụ trong mùa đông ở Pháp. Các yếu tố hình dạng mực nước là các tham số nhạy cảm nhất. Độ rỗng thoát nước nhạy hơn một chút so với độ dẫn thủy lực trong dự đoán lưu lượng thoát nước, trong khi độ dẫn thủy lực thì nhạy hơn một chút trong dự đoán độ cao mực nước. So sánh giữa các đường cong lưu lượng dài hạn thực nghiệm và mô phỏng, cũng như thời gian vượt quá mực nước, cho thấy mô hình có thể là một công cụ hữu ích để đánh giá hiệu suất và kiểm soát tính thích hợp của một thiết kế thoát nước ngầm nhất định.

Ethiopia’s irrigation potential is estimated at 3.7 million hectare, of which only about 190,000 ha (4.3% of the potential) is actually irrigated. There is little information on the extent to which the so far developed irrigation schemes have been effective in meeting their stated objectives of attaining food self-sufficiency and eradicating poverty. Therefore, the aim of this paper is to identify the impact of small-scale irrigation on household food security based on data obtained from 200 farmers in Ada Liben district of Ethiopia in 2006. The resulting data was analyzed using Heckman’s Two-step Estimation procedure. Studies elsewhere revealed that access to reliable irrigation water can enable farmers to adopt new technologies and intensify cultivation, leading to increased productivity, overall higher production, and greater returns from farming. Our study findings confirm some of these claims. In the study area about 70% of the irrigation users are food secure while only 20% of the non-users are found to be food secure. Access to small scale irrigation enabled the sample households to grow crops more than once a year; to insure increased and stable production, income and consumption; and improve their food security status. The study concludes that small-scale irrigation significantly contributed to household food security.

A non-linear explicit inverse solution method for the operational control of remotely controlled canal systems is presented. The model accounts for canal seepage, turnout flows (point sink), control structures with steeply varying and/or discontinuous discharge characteristics. The governing unsteady flow equations are solved backward both in space and time. For each space interval, the use of finite difference approximations for the operational problem results in a system of two non-linear equations in two unknowns. These equations are solved using Newton's method. The method is extended to canal networks. The canal junctions are classified into three types. The controllability of flow for each type of canal junction and for the network as a whole are discussed. The model, though explicit, is found to be unconditionally stable. The model results are verified with the unsteady flow simulation model based on non- linear Preissmen's scheme. The applicability of the model to a canal system is demonstrated.

Large-scale canal irrigation projects are commonly seen as profligate users of water. Their low water productivity has been attributed by many authors to deficiencies in management or to actions by farmers to circumvent management control over water distribution. Inadequate design has sometimes been cited as a contributing factor, but the relationship between design and manageability has received too little attention. In most conventional large-scale irrigation systems imperfect matching between water supply and demand is an inescapable fact of life that leads to operational spillages and low efficiency. Provision of auxiliary storage reservoirs at strategic points within the canal system can buffer this mismatch and improve service delivery and also aid recovery of return flows. Such reservoirs may bring additional benefits in that they provide opportunities for multiple-use management and increased productivity of irrigation water. This paper presents a case study of Mahaweli System H in Sri Lanka, which incorporates a large number of secondary reservoirs within its 25000 ha command area. The paper examines current operational performance and considers scope for and constraints to multiple-use management.

This paper describes a role playing planning exercise that has been used for training agriculturists, engineers and agricultural economists for more than ten years. It sets out the objectives and key features of the exercise and the experience that has been gained in its use. The exercise has been found to successfully test and integrate subject matter expertise acquired from formal teaching. It also highlights the multiple and often conflicting objectives of irrigation planning, and the need for full evaluation of alternatives and sound technical judgements under conditions of inadequate data and time pressure. The exercise is also successful in developing professional personal skills such as group working, interviewing and presentation, and is recommended as an effective training aid.

Without doubt the performance indicator that has so far received least attention in irrigation is the reliability of irrigation service. A review of reliability approaches as reflected in the literature is made and the analysis leads to propose a new conceptual framework for reliability of irrigation. The reliability of irrigation service is defined as the degree to which the irrigation system, and its water deliveries, conform to the prior expectations of its users. The perception of the user is central to the process of defining expectations and to the process of making strategic and tactical choices for the cropping pattern, the quantity of inputs, etc. It is proposed here to use a composite reliability approach, combining two key aspects: the variability and the predictability of the service characteristics. The methodology consists firstly of defining a set of three, non-overlapping, first-order indicators which fully characterize irrigation deliveries. These indicators are: Adequacy, Timeliness and Steadiness. Then the variation (in time or in space) of these indicators leads to “Second-order indicators” of performance. One second-order indicator is the well-known Equity, which assesses the spatial distribution or the distribution between shareholders. Variability and predictability are the two main aspects of the proposed concept of reliability. The variability is the temporal variation of the first-order indicators while the predictability defines the extent to which irrigation can be forecast. Low variability means high predictability, whereas high variability does not necessarily mean low predictability, as patterns of variation can possibly be deduced from past events. The reliability is inversely proportional to the frequency and the magnitude of failure. Here the magnitude of failure in irrigation service is measured by the deviation of the actual from the expected delivery. Existing approaches and the proposed conceptual framework are applied to a case study in the Punjab-Pakistan. It shows that reliability indicators proposed so far are not doing any better than the classical approach of adequacy. The new proposed approach for reliability, based on the combination of variability and predictability, seems more promising. Finally this preliminary analysis also identifies several key domains for which further investigations should be undertaken to increase the general understanding of reliability.