Irrigation and Drainage Systems : Research and Development in the 21st Century

One critical problem confronting mankind today is how to manage the intensifying competition for water between expanding urban centres, traditional agricultural activities and in-stream water uses dictated by environmental concerns. In the agricultural sector, the dwindling number of economically attractive sites for large-scale irrigation and drainage projects limits the prospects of increasing the gross cultivated area. Therefore, the required increase in agricultural production will necessarily rely largely on a more accurate estimation of crop water requirements on the one hand, and on major improvements in the construction, operation, management and performance of existing irrigation and drainage systems, on the other. The failings of present systems and the inability to sustainably exploit surface and groundwater resources can be attributed essentially to poor planning, design, system management and development. This is partly due to the inability of engineers, planners and managers to adequately quantify the effects of irrigation and drainage projects on water resources and to use these effects as guidelines for improving technology, design and management. To take full advantage of investments in agriculture, a major effort is required to modernize irrigation and drainage systems and to further develop appropriate management strategies compatible with the financial and socio-economic trends, and the environment. This calls for a holistic approach to irrigation and drainage management and monitoring so as to increase food production, conserve water, prevent soil salinization and waterlogging, and to protect the environment. All this requires, among others, enhanced research and a variety of tools such as water control and regulation equipment, remote sensing, geographic information systems, decision support systems and models, as well as field survey and evaluation techniques. To tackle this challenge, we need to focus on the following issues: \u2022 affordability with respect to the application of new technologies; \u2022 procedures for integrated planning and management of irrigation and drainage systems; \u2022 analysis to identify causes and effects constraining irrigation and drainage system performance; \u2022 evapotranspiration and related calculation methods; \u2022 estimation of crop water requirements; \u2022 technologies for the design, construction and modernization of irrigation and drainage systems; \u2022 strategies to improve irrigation and drainage system efficiency; \u2022 environmental impacts of irrigation and drainage and measures for creating and maintaining sustainability; \u2022 institutional strengthening, proper financial assessment, capacity building, training and education. Copyrigh

Debris and Hyper-concentrated Flows : Overview and Perspective

Debris and hyper-concentrated flows are among the most destructive of all water \u2013 related disasters. They mainly affect mountain areas in a wide range of morpho-climatic environments and in recent years have attracted more and more attention from the scientific and professional communities and concern from public awareness, due to the increasing frequency with which they occur and the death toll they claim. In this context, achieving a system of debris and hyper-concentrated flow constitutive equations is a task which has been given particular attention by scientists during the second half of the last Century. In relation to these issues, the paper reviews the most updated and effective procedures , nowadays available, suitable to predict the triggering and mobilising processes of these phenomena and proposes a new set of mathematical models able to assess the depth of the wave and the velocities of the liquid and solid phases of both non-stratified (mature) and stratified (immature) flows following flash-floods and dam-break events , in one and two dimensional schemes. Different experimental cases of dam-break situations in a square section channel were considered for the purpose of comparing results. These tools will allow, on one hand, to better focus what to observe in the field and, on the other hand, improve both mitigation measures and hazard mapping procedures

Thermal fluid dynamics of water droplet in sprinkler irrigation : Phenomenological analysis and modelling

A thorough understandingof the factors affecting spray flow and evaporation losses in sprinkler irrigation is important for developing appropriate water conservation strategies. To properly tackle this problem ,relevant theoretical and experimental studies have been carried out during the second half of the last century. Notwithstanding all these efforts, the phenomenon of aerial evaporation of droplets exiting from a nozzle has not been fully understood yet and something new has to be added to the description of the process to reach a better assessment of the events. To this end, a mathematical model for irrigation sprinkler droplet ballistics , based on a simplified dynamic approach to the phenomenon ,has been presented. The model proves to fully match the kinematic results obtained by more complicated procedures. Moreover,fiel trials showed the model to reliably estimate spray evaporation losses caused by environmental conditions. Further analytical and experimental activities are needed to gain a better understanding of water flow and waste in sprinkler irrigation practice

A Report on the 40th International Symposium Actual Tasks on Agricultural Engineering, 21-24 February 2012, Opatija, Croatia

The 40th International Symposium, Actual Tasks on Agricultural Engineering, was held on 21-24 February 2012 in the “Grand Hotel Adriatic”, Opatija, in the Republic of Croatia. It was organized by the Agricultural Engineering Department of the Faculty of Agriculture of the University of Zagreb, and was supported by the Department of Agricultural Engineering of the Faculty of Agriculture of the J.J. Strossmayer University, Osijek, the Department of Bio-Systems Engineering of the Faculty of Agriculture of the University of Maribor, Slovenia, the Agricultural Institute of Slovenia, the Hungarian Institute of Agricultural Engineering Gödöllö, and the Croatian Agricultural Engineering Society. The Symposium also enjoyed the support of the CIGR publishing house, the EurAgEng (the European Society of Agricultural Engineers), the AAAE (the American Association for Agricultural Education), the AAESEE (the Association of Agricultural Engineers of South Eastern Europe), and the ASABE (the American Society of Agricultural and Biological Engineers)