Reliability criteria for re-engineering of large-scale pressurized irrigation systems

Presented during the Third international conference on irrigation and drainage held March 30 - April 2, 2005 in San Diego, California. The theme of the conference was "Water district management and governance."Includes bibliographical references.A study was conducted in a pressurized irrigation district in southern Italy to analyze current delivery performance and determine improvements needed to meet current and future delivery needs. Such an analysis is required due to changes that have occurred, since the system was first put into service, in cropping patterns, farming practices and irrigation techniques. The Combined Optimization and Performance Analysis Model (COPAM) was used to evaluate the irrigation system present performance under different operating conditions, to identify the areas within the irrigation district where rehabilitation and modernization are more urgently needed, and to suggest the most effective engineering and operational improvements. Post-intervention operating scenarios were simulated and analyzed to refine and validate the re-engineering process. Results show the usefulness of simulation models when analyzing modernization alternatives for irrigation schemes.Sponsored by USCID; co-sponsored by Association of California Water Agencies and International Network for Participatory Irrigation Management

Environmental sustainability

Presented at Ground water and surface water under stress: competition, interaction, solutions: a USCID water management conference on October 25-28, 2006 in Boise, Idaho.Includes bibliographical references.A study was conducted on a large-scale irrigated area located in southern Italy to analyze the cumulative effects of long-term water management practices on soils and aquifers. Assessing the environmental sustainability of irrigation systems operations was the main goal of the present research. This included envisaging feasible changes to "business-as-usual" in the study area with the aim of reducing pressures and of meeting current and future management objectives. The Determinants-Pressure-State-Impact-Response methodology suggested by the European Environmental Agency was applied to the case study to analyze cause-effect relationships between driving forces, pressures and potential impacts. Simulations of alternatives in water management and evaluation of resulting consequences were conducted by developing a spatial Decision Support System (DSS) on the study area. This basically involved development and ranking of alternatives by using a commercial software package (DEFINITE DSS). Evaluation of the most likely resulting consequences was conducted by creating maps of environmental risk by means of two commercial GIS software packages (ArcGIS and IDRISI). The used approach showed its usefulness for achieving better understanding of relevant aspects related to management of irrigation water at regional scale, for designing strategic monitoring programs to be implemented and for envisaging feasible management alternatives on large-scale irrigation systems

Generating Hydrants’ Configurations for Efficient Analysis and Management of Pressurized Irrigation Distribution Systems

Water scarcity is a mounting problem in arid and semi-arid regions such as the Mediterranean. Therefore, smarter and more effective water management is required, especially in irrigated agriculture. One of the most challenging uncertainties in the operation of on-demand collective Pressurized Irrigation Distribution Systems (PIDSs) is to know, a priori, the number and the position of hydrants in simultaneous operation. To this end, a model was developed to generate close to reality operating hydrants configurations, with 15, 30 or 60 min time steps, by estimating the irrigation scheduling for the entire irrigation season, using climatic, crop and soil data. The model is incorporated in an integrated DSS called Decision Support for Irrigation Distribution Systems (DESIDS) and links two of its modules, namely, the irrigation demand and scheduling module and the hydraulic analysis module. The latter is used to perform two types of analyses for the performance assessment and decision-making processes. The model was used in a real case study in Italy to generate hydrants’ operation taking into consideration irrigation scheduling. The results show that during the peak period, hydrants simultaneity topped 62%. The latter created pressure deficit in some hydrants, thus reducing the volume of water supplied for irrigation by up to 87 m3 in a single hydrant during the peak demand day. The developed model proved to be an important tool for irrigation managers, as it provides vital information with great flexibility and the ability to assess and predict the operation of PIDSs at any period during the irrigation season

Perspectives in Resource Management and Climate Change Adaptation in the Southern and Eastern Mediterranean. MEDPRO Policy Paper No. 6, March 2013

This policy paper focuses on the sustainable management of some key natural resources in southern and eastern Mediterranean countries (SEMCs) under climate change and anthropogenic pressures. In a business-as-usual and even more so in a failed cooperation scenario, water resources, ecosystems and biodiversity in the region are under stress, with negative consequences for agriculture, food security, tourism and development. However, proper adaptation strategies are shown to be effective in reconciling resource conservation with GDP, trade and population growth. These need be implemented in different ways: technological, institutional, behavioural; and at different levels: regional, national and international. There is ample room for fruitful cooperation between the EU and SEMCs in this area, which can take the form of EU direct financial and technical support when resources in SEMCs are scarce, and of multilateral and bilateral cooperation programmes to improve resource efficiency. The EU could also take on the role of coordinating these different bilateral actions and, at the same time, support SEMCs to establish a structured programme focused on the communication and dissemination of emerging best practices

Decision Support Tool for the Optimal Sizing of Solar Irrigation Systems

Solar photovoltaic (PV) irrigation is increasingly used in agriculture, driven by its low operation cost and virtually zero emissions, providing electricity access in rural areas. However, the high investment cost requires an optimal design. The objective of this work was to develop a user-friendly tool to optimally size a PV generator that satisfies crop irrigation needs under local constrictions. The ODSIS (Optimal Design of Solar Irrigation System) tool, was organized in three calculation modules, preceded by two complements, which determine the daily crop irrigation needs and power demand of the pumping system. Then, the first module sizes the PV plant, considering a multiplication factor, and provides the PV production potential throughout each day of the season. The second and third modules evaluate the total investment cost and equivalent greenhouse gas emissions avoided by comparison with traditional energy sources. This tool was applied to a case study in Senegal for which a multiplication factor of 1.4 was obtained for the optimal PV plant size. Between 22% to 64% of the investment cost corresponded to the PV pumping system, depending on the irrigation technique. The use of PV energy in the case study would represent an annual economic saving for the farmer after 5 to 8 years of payback period, avoiding the emission of between 29.8 and 37.9 tCO2eq/year for the case study area

Decision Support Tools for wastewater management and for water & land management in agriculture

This deliverable provides the description and the user guides for two Decision Support Tools (DSTs) relative to wastewater management and water & land management in agriculture, developed in the MADFORWATER project. The actual software and codes relative to these two DSTs have been deposited in open access repositories, and the corresponding links are reported in this deliverable. The first DST (Poseidon 2.0) compares different water-reuse options and it shows decision makers implementable solutions for wastewater treatment which comply with local requirements. It was developed in the framework of Task 5.2 of MADFORWATER - Strategies and economic instruments for WW management. Section 2.1 describes the DST and provides the links where it can be downloaded. A dedicated handbook explaining how to use the DST is included in Appendix I. The second DST is an integrated agro-economic model developed in Tasks 3.3 and 5.3, aimed at integrating water reuse and irrigation technologies (developed, tested and implemented in the MADFORWATER project) with economic instruments into basin-scale strategies to enhance the use of treated wastewater. Section 2.2 describes this DST and provides the links where it can be downloaded. A dedicated handbook explaining how to use the DST is included in Appendix II

WW management strategies and water & land management strategies in agriculture

The general objective of the MADFORWATER project is to develop integrated technological and management solutions to boost wastewater treatment and treated wastewater efficient reuse for irrigation in selected hydrological basins in Egypt, Morocco and Tunisia. In particular, Work Package (WP) 5 ‘’ Strategies and economic instruments for basin-scale water resources management’’ aims to develop strategies for wastewater management, water reuse and water & land management in agriculture, tailored to the three studied basins. This WP will make use of two decision support tools (DSTs) to support the development of strategies and economic instruments for wastewater management and water & land management in agriculture. In this deliverable 5.2, the wastewater management strategies and the strategies for water management in agriculture are developed separately. The proposed two types of strategies will then be combined into basin-scale integrated water & land management strategies in the upcoming deliverable 6.1

Modelos para a simulacao integrada visando o projecto e a analise do desempenho de redes de rega em pressao funcionando a pedido

The integrated modeling approach intends to provide for design and performance analysis of on-demand pressurized irrigation systems using several flow regimes. A water balance model (WBM) is used for computing demands at the hydrant level. By aggregating such demands., the distribution of the discharges at the upstream end of an on-demand irrigation system is obtained. This provides for the selection of the maximum discharge to be supplied by the network according to a present operation quality. After selecting the upstream discharge a random generation model (RGM) is used to generate a large range of discharge configurations. The Labye iterative discontinuous method and a linear programming formulation have been extended for computing the optimal pipe diameters when several flow regimes occur. Networks designed in that way are analysed. Models (AKLA, FLUCS) have been tested developed and validated in order to perform the hydraulic analysis of the system, including the impacts of the characteristics curves of the hydrants and of the upstream flow limiters. The analysis is completed with computational of performance indicators., reliability and resilience, for each hydrant using random generated configurations of hydrant simultaneously operating. Based on these analysis the designer may decide when the design is satisfactory or to proceed with further improvements. The results obtained for case studies that this novel integrated approach, respect to the classical one, leads to ore reliable solutions that better respond to the variation of possible future scenarios, although the cost of network remain almost the sameAvailable from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga

Perturbation Indicators for On-Demand Pressurized Irrigation Systems

The perturbation in hydraulic networks for irrigation systems is often created when sudden changes in flow rates occur in the pipes. This is essentially due to the manipulation of hydrants and depends mainly on the gate closure time. Such a perturbation may lead to a significant pressure variation that may cause a pipe breakage. In a recent study, computer code simulating unsteady flow in pressurized irrigation systems—generated by the farmers’ behavior—was developed and the obtained results led to the introduction of an indicator called the relative pressure variation (RPV) to evaluate the pressure variation occurring into the system, with respect to the steady-state pressure. In the present study, two indicators have been set up: The hydrant risk indicator (HRI), defined as the ratio between the participation of the hydrant in the riskiest configurations and its total number of participations; and the relative pressure exceedance (RPE), which provides the variation of the unsteady state pressure with respect to the nominal pressure. The two indicators could help managers better understand the network behavior with respect to the perturbation by defining the riskiest hydrants and the potentially affected pipes. The present study was applied to an on-demand pressurized irrigation system in Southern Italy