USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Centre pivot irrigation systems are known for their irrigation distribution performance potential. Unfortunately the performance analysis of centre pivot irrigation systems is often restricted to the uniformity of distribution. Depending on the characteristics of the applied rainfall, a system designed for high uniformity does not guarantee a high application efficiency once the system is in operation. A method is proposed in the present paper to analyse the average rainfall depth of application and kinetic energy delivered to the soil by individual droplets all over the machine. The method requires water distribution profiles, the distribution of droplet size and velocity along the radius of coverage for any nozzle, and pressure and height of the emitter installed on the machine. Considering the number of nozzles and the range of pressure applied, there is the need for a method calculating: the emitter maximum radius of coverage, then the rainfall distribution profile, then the droplet distribution and finally the associated kinetic energy delivery. These parameters are calculated on a new model of classical design sprayers proposed by IWT Company. These results are being integrated on a centre pivot nozzle chart design software presented in the poster session

Assessment of clogging effects on lateral hydraulics: proposing a monitoring and detection protocol

International audienceAgeing of drip irrigation systems due to clogging of emitters is considered the largest maintenance problem in microirrigation and this problem is enhanced in subsurface irrigation systems. Whatever the source of the clogging problem, a methodology for early detection of clogging in the field can be useful in decision-making about deploying cleaning processes (flushing or injection of chemicals) and avoiding replacement of laterals. This work presents a methodology for simulating clogging conditions able to reproduce the effects of clogging on pressure profiles, head loss, and emitters flow rate distribution along a single levelled lateral with constant inlet pressure. This methodology was validated by several experiments conducted under controlled conditions of clogging induced by changes in the flow rate of emitters. The effects of clogging intensity and position on hydraulic parameters of a single lateral were analysed in detail and aspects relating to pressure, head loss, and flow rate measurements were discussed. For a given lateral set-up, it is possible to draw a chart relating flow rate and head loss for various levels and positions of clogging. Assuming that measurements of head loss and flow rate are available, this diagram enables immediate estimation of the level and location of clogging

Ueber die Reduktion des Cineols

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Réutilisation maîtrisée des eaux usées : approfondir les connaissances pour lever les freins et relever les défis

Le recyclage des eaux usées représente une solution pour faire face à la demande croissante des ressources hydriques pour l’irrigation agricole. Mais leur réutilisation pose des problèmes de sécurité, de réglementation et bien sûr de techniques adaptées, que cet article nous propose de mieux comprendre

Méthode d'évaluation de l'action de conseil en irrigation IRRIPARC en régions Nord-Pas-de-Calais et Picardie

Parmi les nombreuses actions de conseil en irrigation développées en France, trop peu d'entre elles sont évaluées pour apprécier leur impact sur les pratiques d'irrigation et les bénéfices pour la ressource. Dans cet article, nous proposons une méthode d'évaluation de l'une d'entre elles, sur l'étude d'un cas concret : l'action IRRIPARC. Dans les régions Nord-Pas-de-Calais et Picardie, des fiches de réglages de canons enrouleurs ont été diffusées aux agriculteurs, pour limiter les effets du vent sur l'uniformité de la répartition de l'eau d'irrigation. La méthode d'évaluation proposée repose sur l'étude de trois critères : l'efficacité, la pertinence et la cohérence de l'action. La collecte des données se fait par enquêtes quantitatives et qualitatives auprès de différents acteurs : les agriculteurs, public cible de l'action, et les partenaires impliqués dans l'action IRRIPARC. L'analyse débouche sur des perspectives d'évolution et fournit des recommandations pour l'action. / Several technical support actions in irrigation have been carried out in France. However, very few have been evaluated to determine their actual impact on irrigation practices and their water saving benefits. In this paper, an assessment method of a technical support action is presented on a concrete case: the IRRIPARC action. The action was carried in the Nord Pas-de-Calais region of France. It aims at providing to farmers technical forms to help them to set their irrigation guns according to the wind speed in order to improve water distribution uniformity. The method depends on three criteria based on the effectiveness, the relevance and the consistency of the action. The data have been collected through quantitative and qualitative enquiries to different stakeholders: farmers to which the action was intended, and other partners which were involved in the action. The analysis results in evolution perspective of IRRIPARC action

Methicillin Resistant Staphylococcus aureus (MRSA) in market age pigs on-farm, at slaughter and retail pork

This study was conducted to determine the occurrence and prevalence of methicillin resistant Staphylococcus aureus (MRSA) in finishing pigs on-farm, at lairage and assess the likelihood of carriage at slaughter and retail levels. A cross-sectional study targeting ten cohorts of commercial swine farms was conducted for carriage of MRSA

Information-theoretic sensitivity analysis: a general method for credit assignment in complex networks

Most systems can be represented as networks that couple a series of nodes to each other via one or more edges, with typically unknown equations governing their quantitative behaviour. A major question then pertains to the importance of each of the elements that act as system inputs in determining the output(s). We show that any such system can be treated as a ‘communication channel’ for which the associations between inputs and outputs can be quantified via a decomposition of their mutual information into different components characterizing the main effect of individual inputs and their interactions. Unlike variance-based approaches, our novel methodology can easily accommodate correlated inputs