121,846 research outputs found
Comment on Book “Empowering Knowledge and Innovation. Challenges for the Arab Countries”
No full textNon
Sull'utilizzo delle curve caratteristiche indicizzate di una rete irrigua per il dimensionamento degli impianti di sollevamento
No full textAdvanced Computer Technologies for Integrated Agro-Hydrologic Systems Modeling: Coupled Crop and Hydrologic Models for Agricultural Intensification Impacts Assessment
No full textL'accoppiamento di modelli idrologici e di coltura sta diventando sempre più un compito importante quando si affrontano gli studi sui sistemi agro-idrologici. Sia per la conservazione delle risorse che per il miglioramento dei sistemi di coltivazione, le complesse interazioni tra regime idrologico e componenti di gestione delle colture richiedono un approccio integrativo per essere pienamente compresi. Tuttavia, la letteratura offre risorse limitate sull'accoppiamento di modelli che si rivolgono agli scienziati ambientali. In effetti, le guide principali sono destinate principalmente agli specialisti di computer e le rendono difficili da comprendere e da applicare. Per colmare questa lacuna, presentiamo un'estesa ricerca sui modelli di coltura e sui modelli idrologici che si rivolgono agli studi di modellizzazione agro-idrologica della terra nella sua complessità integrativa. L'obiettivo principale è capire la relazione tra l'intensificazione agricola e il suo impatto sull'equilibrio idrologico. Abbiamo fornito documentazione, classificazioni, applicazioni e riferimenti delle tecnologie disponibili e delle tendenze di sviluppo.
Abbiamo applicato i risultati dell'indagine accoppiando il modello idrologico DREAM con il modello di coltura DSSAT. Entrambi i modelli sono stati aggiornati sia sulla sorgente del codice (DREAM) che sulla base operativa (DSSAT) per l'interoperabilità e la parallelizzazione. Il modello risultante opera su una griglia e su un passo giornaliero. Il modello viene applicato nell'Italia meridionale per analizzare l'effetto dell'applicazione del fertilizzante sulla generazione di ruscellamento tra il 2000 e il 2013. I risultati dello studio mostrano un impatto significativo dell'applicazione dell'azoto sulla resa idrica. Infatti, quasi 71,5 mila metri cubi di acqua piovana per ogni chilogrammo di azoto e per ettaro vengono persi come riduzione del coefficiente di deflusso. Inoltre, una correlazione significativa tra la quantità di applicazioni di azoto e il deflusso si trova su base annuale con il coefficiente di Pearson di 0,93.Coupling hydrologic and crop models is increasingly becoming an important task when addressing agro-hydrologic systems studies. Either for resources conservation or cropping systems improvement, the complex interactions between hydrologic regime and crop management components requires an integrative approach in order to be fully understood. Nevertheless, the literature offers limited resources on models’ coupling that targets environmental scientists. Indeed, major of guides are are destined primarily for computer specialists and make them hard to encompass and apply. To address this gap, we present an extensive research to crop and hydrologic models coupling that targets earth agro-hydrologic modeling studies in its integrative complexity. The primary focus is to understand the relationship between agricultural intensification and its impacts on hydrologic balance. We provided documentations, classifications, applications and references of the available technologies and trends of development.
We applied the results of the investigation by coupling the DREAM hydrologic model with DSSAT crop model. Both models were upgraded either on their code source (DREAM) or operational base (DSSAT) for interoperability and parallelization. The resulting model operates at a grid base and daily step. The model is applied southern Italy to analyze the effect of fertilizer application on runoff generation between 2000 and 2013. The results of the study show a significant impacts of nitrogen application on water yield. Indeed, nearly 71.5 thousand cubic-meter of rain water for every kilogram of nitrogen and per hectare is lost as a reduction of runoff coefficient. Furthermore, a significant correlation between the nitrogen applications amount and runoff is found at a yearly basis with Pearson’s coefficient of 0.93.Le couplage des modèles hydrologiques et culturaux est une tâche importante lorsqu’on aborde les études de systèmes agro-hydrologiques. Que ce soit pour la conservation des ressources ou l’amélioration des systèmes de culture, les interactions complexes entre le régime hydrologique et les composantes de la gestion des cultures nécessitent une approche intégrative pour être pleinement comprises. Néanmoins, la littérature offre des ressources limitées sur le couplage de modèles qui cible les scientifiques. En effet, la plupart des guides sont principalement destinés aux informaticiens et sont difficiles à appliquer. Pour combler cette lacune, nous présentons une recherche approfondie sur le couplage des modèles de cultures et des modèles hydrologiques, qui cible les études de modélisation agro-hydrologique dans leur complexité intégrative. L'objectif principal est de comprendre la relation entre l'intensification agricole et ses impacts sur l'équilibre hydrologique. Nous avons fourni des documentations, des classifications, des applications et des références des technologies disponibles et des tendances de développement.
Nous avons appliqué les résultats de l'enquête en couplant le modèle hydrologique DREAM au modèle de culture DSSAT. Les deux modèles ont été mis à niveau soit sur leur code source (DREAM), soit sur leur base opérationnelle (DSSAT) pour assurer l’interopérabilité et la parallélisation. Le modèle résultant est appliqué dans le sud de l'Italie pour analyser l'effet de l'application d'engrais sur la production de ruissellement entre 2000 et 2013. Les résultats de l'étude montrent un impact significatif de l'application d'azote sur l'apport en eau. En effet, près de 71 500 mètres cubes d'eau de pluie par kilogramme d'azote et par hectare sont perdus sous la forme d'une réduction du coefficient de ruissellement. De plus, une corrélation significative entre la quantité d’application d’azote et le ruissellement est constatée chaque année avec un coefficient de Pearson de 0,93
Modern strategies and tools for water saving and drought mitigation in Southern Italy. In “Drought management: Scientific and technological innovation
No full textAssessing pressure changes in an on-demand water distribution system on drip irrigation performance - a case study in Italy
No full textThe hydrant pressure head in an on-demand water distribution system can be subject to high fluctuation depending on the discharge flowing inside the pipes, with consequent impacts on the performance of on-farm irrigation systems. In this work, an Italian water distribution system was analyzed using the AKLA model at upstream discharges of 1,200 and 600 L center dot s(-1) to estimate the range of hydrant pressure variation. A computer model was developed, calibrated, and used to evaluate the performance of a drip irrigation system by relating the on-farm network with the hydrant characteristic curve at a certain operating status. The flow regulator within the hydrant played an important role in stabilizing the performance of the network at hydrant pressures higher than 27 m. At lower hydrant pressures, to apply the same amount of water, irrigation time must be extended by 17 and 95% for pressure heads of 20 and 12 m, respectively. These approaches described have great utility to ensure adequate irrigation management when water is delivered by pressurized on-demand systems
Closure to “Assessing Pressure Changes in an On-Demand Water Distribution System on Drip Irrigation Performance—Case Study in Italy”
No full textEnergy saving for a pumping station serving an on-demand irrigation system: a study case
No full textOn-demand pressurized water distribution system impacts on sprinkler network design and performance
No full textOn-farm irrigation networks are designed for optimum performance at a specific upstream pressure head. In pressurized water distribution systems operating on demand, the upstream pressure head of the on-farm network can be subject to high and continuous fluctuations depending on the number of the hydrants being simultaneously opened. In this paper, a methodology combining network design and performance analysis of a sprinkler network is described and applied to an irrigation distribution system operating at two different water demands (1,200 and 600 l s -1) using a case study in Italy. Four designs of the same sprinkler network were optimized at different upstream designing pressure and were evaluated at all the possible operating conditions of the system. The expensive large pipe size diameter design presented the best performance and the highest reliability at a wide range of hydrant pressure while the small pipe size designs have the tendency to fail during the peak water demand period as a result of low hydrant pressure. Flow regulators within the hydrants showed to have an important role in stabilizing the network performance at elevated upstream pressure head
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