National Irrigation Systems Research Articles

An assessment of farmers' perspective in support of the modernization of national irrigation systems in the Philippines*

AbstractThe National Irrigation Administration (NIA) has been involving farmer‐irrigators of national irrigation systems (NIS) in planning system improvement and management since the 1980s. It has conducted various organization‐strengthening and capacity‐building programmes for members of irrigators associations. Unfortunately, unauthorized diversions, vandalism of structures, over‐irrigation in upstream farms while downstream farms fall dry, conflicts over water distribution, and non‐adoption of field‐demonstrated water‐saving techniques still occur in several systems.Consultation‐workshops were conducted with farmer representatives of two small‐scale NIS to gain understanding of the causes of such social disharmony, which hinders good system performance. The present case study was specifically aimed at the following: examining the farmer‐irrigators' desired physical structures, system operation, water distribution rules, and institutional arrangements for their respective NIS vis‐à‐vis their envisioned quality of water delivery service; determining the levels of consistency of the desired irrigation technology and techniques; and generating data input for formulating programmes aimed at enhancing farmer‐irrigators' appreciation of the operational procedures and mechanisms of water delivery.The results of the consultation‐workshops showed conflicting farmers' preferences for system modernization options. The findings implied that a participatory approach to system modernization planning would be more fruitful when farmers are equipped to make informed choices on possible improvement solutions.

Modernization of National Irrigation Systems in the Philippines: Linking Design, Operation and Water Supply

AbstractThe consistent gap between the irrigation service area and irrigated areas of national irrigation systems has been attributed to shortcomings either in design, technology, system operation, maintenance and management, policy, climate change, or a combination of these factors. Conventional rehabilitation, which mainly involves restoration of irrigation structures, has had little impact in closing this gap.This study examined the irrigation technology and water management techniques employed in two national irrigation systems. Its objectives were to identify technology constraints, cost‐effective improvement practices and the potential for improving system performance with an end view of formulating a relevant modernization approach for national irrigation systems. The study used a logical design framework, field measurements and selected procedures of the Mapping System and Services for Canal Operation Techniques (MASSCOTE) as analytical tools.The findings show that inconsistencies among the design philosophy, system and operational objectives, flow control structures and water supply of the irrigation systems are root causes of their suboptimal performance. Careful consideration of the logical coherence among the selected irrigation technologies, water distribution techniques and water supply availability would form a crucial part of a relevant irrigation modernization planning for the case study systems and other irrigation systems in similar situations. © 2018 John Wiley & Sons, Ltd.

Evaluación del aporte de las cooperativas agrícolas a la construcción de seis sistemas nacionales de riego durante el periodo 1926-1936

En este artículo se describe una buena parte de los procesos científicos, tecnológicos y sociales que demandó la construcción de la infraestructura arquitectónica y social de los Sistemas Nacionales de Riego durante la década que transcurre entre 1926 y 1936. Se trata de un enorme esfuerzo de innovación tecnológica y social que requirió de la participación tanto de la ingeniería norteamericana como de la nacional. En el caso de ésta última representó un reto colosal y, al mismo tiempo, una gran oportunidad para el avance en la especialización técnica. Así mismo, en este trabajo se pone de manifiesto como al lado de la imponente obra hidráulica de los Sistemas Nacionales de Riego, el gobierno federal promovió el cooperativismo agrícola como forma idónea de organización social al interior de estos sistemas con el propósito de llevar a cabo el reparto agrario y la modernización de la agricultura a nivel regional y nacional. La propuesta cooperativista que el Estado buscó aplicar en los Sistemas Nacionales de Riego, fue sustentada por un trabajo previo de legislación en la materia, que otorgó personalidad jurídica a las asociaciones cooperativas. De igual modo, fue alentada por el reconocimiento de los logros de las sociedades cooperativas en diversas regiones del país y por el acceso a información proveniente de otros países. Lamentablemente el estímulo gubernamental no tuvo continuidad en el tiempo y, a pesar de los resultados positivos obtenidos, no fue posible alcanzar la plena consolidación de estas experiencias autogestivas.

Diagnostic Assessment Approach for Formulating a Modernization Strategy for Small‐Scale National Irrigation Systems in the Philippines

AbstractThe utility of a logic design framework and the diagnostic tools of the mapping system and services for canal operation techniques (MASSCOTE) were tested in two small‐scale national irrigation systems (NIS) with an end view of developing a diagnostic assessment methodology that would be relevant to planning for small‐scale irrigation systems modernization. The applicability of the water‐related rapid appraisal procedure (RAP) external indicators and structures sensitivity assessment as diagnostic tools was limited by the lack of flow data and the infeasibility of field experiments due to tight rotational irrigation schedules and laissez‐faire direct offtakes. The discharge–head relations, the hydraulic flexibility concept and the findings from walkthroughs and interviews were pragmatic alternatives. The results of the study show that inconsistency in the system designs and lack of, or poorly performing, flow control structures are the main factors contributing to mediocre irrigation service. The combination of diagnostic techniques and analytical tools used in this study present a useful framework for system diagnosis in small and ungauged irrigation systems. Copyright © 2017 John Wiley & Sons, Ltd.

Climate-based suitability assessment for alternate wetting and drying water management in the Philippines: a novel approach for mapping methane mitigation potential in rice production

ABSTRACTThe ‘alternate wetting and drying’ (AWD) technology for rice is a water-saving technology with a high greenhouse gas (GHG) mitigation potential. The Philippine government attempts to disseminate AWD in all national irrigation systems in order to adapt to increasingly scarce water resources.This article describes how a model for climatic AWD suitability assessment developed by the International Rice Research Institute (IRRI) is suited for a national assessment of the Philippines, and country-scale climatic suitability maps for AWD are develop for wet and dry season. Furthermore, how the assessment can be used to estimate potential GHG emission savings is illustrated.Results show that a maximum of 60% of the rice area of the Philippines is climatically suited to AWD, reaching more than 90% in the dry and 34% in the wet season. The potential, maximum annual reduction is around 265,000t of CH4 emissions from lowland rice in the Philippines, or around 15% of the country's annual emissions from the agriculture sector.The article concludes with recommendations on the use of this simple spatial water balance model for mitigation planning which offers a more spatially detailed, quantitative and transparent estimate of national GHG emissions in the rice sub-sector for rice producing countries.

Irrigation Investments in Romania. Size, Results, Efficiency (1965-1989)

In Romania was equipped for irrigation over than 3 million hectare, one of the greatest surfaces in Europe. The aim - drought control and intensification of agriculture by increasing the yield per hectare. The financial effort was very important - over 10 million USD borrowed from the International Bank for Reconstruction and Development and World Bank. To accelerate the construction of the irrigation systems and to save financial resources the constructors renounced to ones of the main parts of the system: drainage systems, measuring equipment, waterproofing transport canals and for application were provided cheap and hand shifted equipment.Operation of the irrigation systems was defective to: there was not sufficient electric power for pumping water, fertilizers and pesticides and other production factors so that the yields per hectare were 50-70% under projected level. Economically all national irrigation system produced loses instead profits. At present about 1.5 million hectare are within rehabilitation course especially in the Danube Plane, which can be operated in profitability terms.

A non-probabilistic methodology for reliable sustainability planning: An application to the Iraqi national irrigation system

This study describes the use of quadratically constrained linear programming with box and complementarity constraints, combined with a relative 1-norm distance measure, to determine the extent to which the relative weights (w) attached to three sustainability criteria (economic, social, and environmental features) could affect the choice of projects to be implemented. To do so, this paper analyzes alternative proportions of the total projects (m) that should be implemented (e.g., 50% and 25% of the total number of projects) as well as alternative standards (c) to be achieved, on average, for some indices (e.g., 100% and 150% of the average standard values, which represent the mean value of these indices for all projects). The overall analytical results are presented for both linearly and exponentially weighted constraints, using partial derivatives to perform local sensitivity analyses (i.e., for each selected or rejected project), and the results account for the effects of w, c, and m. Next, level curves are prepared over the whole domain for w to produce two-dimensional graphs that support a global sensitivity analysis (i.e., for all selected and rejected projects) and to account for the effects of w, c, and m for both linearly and exponentially weighted constraints. Application of this approach to the Iraqi national irrigation system as a case study showed that the results are less robust if a smaller proportion (25%) of the total projects is chosen, with a change of up to 30% in the projects selected. In this context, an increase in the smallest weights for sustainability criteria also affected project choices. If the average standard to be achieved is made stricter (150% of the average standard), the results become more robust, with a change of less than 5% in the selected projects. In this context, increases in the smallest weights for sustainability criteria did not affect the project choices. The results were less robust with linearly weighted constraints than with exponentially weighted constraints.

Reference Crop Evapotranspiration (ETo) for Irrigation Equipments design in Uruguay

During the last decade, national irrigation systems have expanded to summer field crops and grass, in adition to intensive traditionally irrigated crops. The maximum reference crop evapotranspiration (ETo) is the starting point for their design. Nowadays the value widely used among designers, is the maximum monthly averaged ETo, usually January. This could lead to under-sized equipments which could generate water-deficits during the critical growth stages. The maximum ETo is not a single value as would be the absolute maximum, it varies according to the period considered (daily, weekly, decadic, monthly) and the probability of non-exceedence. In this study daily ETo time series, between 28 and 35 years, recorded in January at the five experimental stations of National Institute of Agricultural Research (INIA) were analyzed. Daily ETo values with 80%probability of non-exeedence were significantly higher than those calculated based on decadic or monthly data. The latter two were quite similar, ranging from 0.1 to 0.3 mm d-1 in the different experimental stations. The aim of this paper is to recommend ETo values to design irrigation systems in Uruguay allowing maximum productive response. The maximum yield does not necessarily correspond with the maximum economic return. Thus is necessary to continue research to evaluate the productive response to different maximum irrigation doses for the different design flows. As a result, a map of Uruguay with ETo isolines based on decadic data with 80% probability of non-exeedence is presented. The equipments designed with this method meet the crop water requirements with a 80% non-exceedence probability (four over five yeas), irrigating 20 hours a day. However, if watering times are increased to 24 hours a day the historical maximum of crop water requirements is covered, except in Salto and Tacuarembó, in which crop demand is covered with a 96 and 97% non-exceedence probability respectively.

Analysis of Irrigation Systems Employing Comparative Performance Indicators: A Benchmark Study for National Irrigation and Communal Irrigation Systems in Cagayan River Basin

Comparative performance analysis of four irrigation schemes within Cagayan River Basin was assessed using comparative performance indicators between the years 2008 and 2012. The objectives were to establish benchmarks for both productivity and performance of irrigation schemes along the valley and to inquire whether small schemes function better than large schemes. The performance evaluation study of the systems composed of three general performance indicators, based on three domains—(1) system operation performance; (2) agricultural productivity and economics; (3) financial performance. Each indicator was assessed based on the prescribed descriptors used by the International Water Management Institute (IWMI) and Food and Agriculture Organization (FAO). Analysis showed an overall system performance efficiency of 59%, 55%, 47% and 36% for Magat River Integrated Irrigation System (MARIIS), Lucban, Garab and Divisoria Communal Irrigation Systems (CIS), respectively. In terms of annual productivity performance, Lucban CIS dominates the three other systems with 0.35 kg/m, which was classified as moderately performing system, while the rest were classified with low productivity index. Financial sustainability of the systems were extremely poor with cost recovery ratio of 0, 0.33, 0.41 and 0.49 for Divisoria, Garab, Lucban and MARIIS, respectively, which were exceptionally below the standard value of at least one. Also, analysis of the indicators revealed that on average, large schemes performed similarly to small-scale schemes, but small schemes were more variable, particularly in input-use efficiency. The benchmarking study will provide strategic information to policy makers of agricultural and irrigation agencies on the existing weaknesses of irrigation systems in the country and determine in a more quantifiable terms levels of potential improvement and intervention targets.

Assessment of the process, nature and impact of rehabilitation for development of a moderniZation strategy for national irrigation systems in the Philippines

AbstractData on medium‐ to large‐scale canal irrigation systems in the Philippines suggest that rehabilitation projects were not sufficient to close the gap between actual area irrigated and irrigation service area. This study analysed the underlying details of various rehabilitation and improvement works in three canal irrigation systems to identify an effective approach to close this gap. The findings show that the rehabilitation works generally focused on maintaining the original canals. Canal lining was the most common improvement work.The planning and design process adopted lacked revalidation of design criteria and assumptions used in the original system design. It did not have the benefit of diagnostic assessment studies. No technical assessments of water supply adequacy for proposed projects were carried out.The findings also indicate that the potential for increasing the actual area irrigated lay in augmentation of water supply, reuse of drainage water, use of adjustable gates at major water distribution points and strategic timing of irrigation schedules between tertiary areas to adapt to prevailing hydrological regimes. Consideration of these findings and an increased attention to consistency among available water supply, irrigation demand, physical design of structures and a realistic operational plan can greatly enhance the impacts of the irrigation modernisation plan in the Philippines. Copyright © 2015 John Wiley & Sons, Ltd.

Reference Crop Evapotranspiration (ETo) for Irrigation Equipments design in Uruguay

During the last decade, national irrigation systems have expanded to summer field crops and grass, in adition to intensive traditionally irrigated crops. The maximum reference crop evapotranspiration (ETo) is the starting point for their design. Nowadays the value widely used among designers, is the maximum monthly averaged ETo, usually January. This could lead to under-sized equipments which could generate water-deficits during the critical growth stages. The maximum ETo is not a single value as would be the absolute maximum, it varies according to the period considered (daily, weekly, decadic, monthly) and the probability of non-exceedence. In this study daily ETo time series, between 28 and 35 years, recorded in January at the five experimental stations of National Institute of Agricultural Research (INIA) were analyzed. Daily ETo values with 80% probability of non-exeedence were significantly higher than those calculated based on decadic or monthly data. The latter two were quite similar, ranging from 0.1 to 0.3 mm d-1 in the different experimental stations. The aim of this paper is to recommend ETo values to design irrigation systems in Uruguay allowing maximum productive response. The maximum yield does not necessarily correspond with the maximum economic return. Thus is necessary to continue research to evaluate the productive response to different maximum irrigation doses for the different design flows. As a result, a map of Uruguay with ETo isolines based on decadic data with 80% probability of non-exeedence is presented. The equipments designed with this method meet the crop water requirements with a 80% non-exceedence probability (four over five yeas), irrigating 20 hours a day. However, if watering times are increased to 24 hours a day the historical maximum of crop water requirements is covered, except in Salto and Tacuarembo, in which crop demand is covered with a 96 and 97% non-exceedence probability respectively.

An alternative approach to sustainable water users' organization in national irrigation systems: the case of the Khlong Thadi Weir System, southern Thailand

AbstractThai national irrigation systems, serving a large number of small paddy farmers, require water users' organization for effective and sustainable joint management; however, water users' organizations (WUOs) presently cover only 27% of the total irrigation area. This three‐year action research investigated the difficulties in organizing water users in the Khlong Thadi Weir System in southern Thailand by immersion into the socio‐economic conditions of Muslim farmers in farm turnout No. 4 of the 1L‐4R‐LMC canal and the conventional on‐farm irrigation development there. We found the following: (1) subsistence farming and unstable tenancy discourage farmers from increasing their formal participation in irrigation management; (2) kinship is important but effective only in a limited space; (3) the conventional method of providing short ditches in a limited project timeframe creates a structural bias; (4) intrinsic internal water conflicts make the hydraulic relationship alone an inadequate basis for water users' organization; (5) alternatively, the social relationship between individual farmers and their community emerges as a promising scaffold for water users' organization; (6) the state irrigation agency should consider adopting a more vital role by supporting WUOs, tambon administration organizations and villages with needed incentives, technical information, and capacity building so that the WUOs are ultimately the decision makers. Copyright © 2008 John Wiley & Sons, Ltd.

Participatory processes and outcomes: the case of national irrigation system management in Bohol, Philippines

AbstractThe adoption of participatory irrigation management in the Philippine national irrigation systems (NIS) began in the mid‐1980s, after positive results were observed in some participatory small‐scale communal irrigation systems. Yet, NIS performance remained generally poor. In the case of the Capayas Irrigation System – an NIS located in Bohol, Philippines – farmer participation is limited, thus sustainability is low. Limited participation is rooted in the absence of initiatives to mobilize the farmers prior to facility construction, inadequate government funds and the consequent priority bias against allocation for institutional development activities. This is also due to the absence of effective mechanisms both for ensuring sanctions against delinquent water users and for promoting incentives for participation. Mechanisms for coordination among various stakeholders are necessary in order to provide an enabling environment for irrigation. Important complementary actions include mainstreaming institutional development support, periodic monitoring and evaluation of the Irrigators' Associations (IAs), and improvements in physical structures of the secondary and tertiary facilities. Copyright © 2007 John Wiley & Sons, Ltd.