Bari Institute

Bari, Italy

Bari Institute

Bari, Italy
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Daccache A.,Cranfield University | Lamaddalena N.,Bari Institute | Fratino U.,Polytechnic of Bari
Journal of Irrigation and Drainage Engineering | Year: 2010

The 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{dot operator}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. © 2010 ASCE.

Daccache A.,Cranfield University | Daccache A.,Bari Institute | Lamaddalena N.,Bari Institute | Fratino U.,Polytechnic of Bari
Irrigation Science | Year: 2010

On-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. © 2009 Springer-Verlag.

Daccache A.,Cranfield University | Weatherhead K.,Cranfield University | Lamaddalena N.,Bari Institute
Outlook on Agriculture | Year: 2010

Numerous previous studies have modelled the impact of climate change on crop water requirements and hence future water resource needs for irrigated agriculture. Fewer have considered the impacts on the performance of irrigation systems and the required engineering and managerial adaptations. This study considers the impacts and adaptations for a typical pressurized pipe irrigation system. The dry years of the baseline period (1970-90) in the southern part of Italy are expected to become the average or even wet year by the 2050s, according to HadCM3 projections. Under these conditions, the large water distribution systems designed to satisfy the baseline dry years will fail unless appropriate engineering or managerial adaptations are made. The resilience of District 8 of the Sinistra Ofanto to the possible future increase in irrigation demand has been assessed. A stochastic weather generator was used to generate future weather under the IPCC A1 and B1 emissions scenarios, taking into consideration the outputs of the HadCM3 model. A daily water balance model was used to quantify the actual and future peak water demand of the district. The reliability of each hydrant under baseline and future demand was calculated using a stochastic hydraulic model and the failure zones identified. Under the current design, the system can tolerate a peak demand discharge up to 1,500 l.s -1, which is below the 2050s' average (1,720 l.s -1). Above that value, the performance of the system will fall drastically as the number of unreliable hydrants will increase. In the future, assuming the same cropping pattern, the threshold discharge (1,500 l.s -1) will be exceeded 80% of the time and, as an average, 20% of the system's hydrants will be failing during the peak demand periods. The adaptation options available to farmers and system managers in response to the increasing demand are discussed.

Khadra R.,Bari Institute | D'Agostino D.R.,Bari Institute | Scardigno A.,Bari Institute | Lamaddalena N.,Bari Institute
Journal of Water and Climate Change | Year: 2011

In the Mediterranean, the increasing social impacts of water scarcity are growing, but effective measures to manage such scarcity are difficult to implement due to the variability of stakeholders and the weak means to handle new policies. To ameliorate the future of water management in the region, communication between stakeholders has to be improved. The Water Framework Directive (WFD 2000) defines a European framework for water management and protection at each hydrological basin level and gives priority to environment conservation through participatory and consultative programmes. In the perspective of developing and analysing a set of comprehensive scenarios of Europe freshwater futures up to 2050, SCENES project (Water Scenarios for Europe and for Neighbouring States) suggests the use of fuzzy cognitive mapping (FCM) as an Information and Communication tool significantly able to support public participation. The present paper reports on the use of FCM in a typical Mediterranean area, the Candelaro river basin in southern Italy, to elicit public perceptions on the current pressures on and state of water resources. Based on these perceptions and down-scaling the global scenarios, local visions of future changes were developed and their potential environmental and socio-economic effects explored. © IWA Publishing 2011.

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