Optimal design of drip irrigation submains: presure-compensating emitters

For a drip irrigation system to be successful, it must he well designed, properly installed, managed and maintained. In plots with steep slopes and irregular topography that have little land leveling capacity and/or that require very efficient agricultural machinery, drip irrigation designs generally use pressure-compensating emitters. This work develops a methodology and implements it in a computer tool that makes it possible to optimally determine in drip-irrigated plots with pressure-compensating emitters: a) telescopic sizing of the submain manifold pipe, b) supply valve pressure and c) subunit''s intake valve location, when considering all hydraulic-economic aspects in the design phase. Techniques of optimal sizing of pipe networks and simulation of hydraulic networks under pressure are linked to economic analyzes of total annualized costs. Finally, the practical usefulness of the proposed methodology is shown with three examples of complex real cases where pipe design costs are reduced by 16-34% and energy costs by 37-51%

A laboratory-based scoring system predicts early treatment in Rai 0 chronic lymphocytic leukemia

We present a laboratory-based prognostic calculator (designated CRO score) to risk stratify treatment-free survival in early stage (Rai 0) chronic lymphocytic leukemia developed using a training-validation model in a series of 1,879 cases from Italy, the United Kingdom and the United States. By means of regression analysis, we identified five prognostic variables with weighting as follows: deletion of the short arm of chromosome 17 and unmutated immunoglobulin heavy chain gene status, 2 points; deletion of the long arm of chromosome 11, trisomy of chromosome 12, and white blood cell count>32.0x103/microliter, 1 point. Low, intermediate and high-risk categories were established by recursive partitioning in a training cohort of 478 cases, and then validated in four independent cohorts of 144/395/540/322 cases, as well as in the composite validation cohort. Concordance indices were 0.75 in the training cohort and ranged from 0.63 to 0.74 in the four validation cohorts (0.69 in the composite validation cohort). These findings advocate potential application of our novel prognostic calculator to better stratify early-stage chronic lymphocytic leukemia, and aid case selection in risk-adapted treatment for early disease. Furthermore, they support immunocytogenetic analysis in Rai 0 chronic lymphocytic leukemia being performed at the time of diagnosis to aid prognosis and treatment, particularly in today's chemo-free era

Regional hydrological modelling of irrigation and drainage systems : case study in Argentina

A proper understanding of the interaction of irrigation and drainage canals with an aquifer system is necessary to improve performance of irrigation. A further complication is that this mechanism must be studied with a detail sufficient to identify operational guidelines for specific portions of an irrigation and drainage system. Numerical simulation models provide a useful support in this respect, since specific operational procedures of irrigation and drainage canals can be evaluated in this way. The objective of this paper is to demonstrate the use of the model SIMGRO in an irrigated area in the Province of Mendoza as a support to decision-making of water management aspects. The regional hydrologic model SIMGRO simulates the water flow in the saturated zone, the unsaturated zone and the surface water. It takes into account the effects of irrigation and drainage systems and its impact on the evapotranspiration of the different land uses. Irrigated by the Lower Tunuyan River, the selected study area was 27,500 ha. It was defined by means of a finite element network consisting of 443 nods and the distance between nodes is of some 1000 metres. The model was run for the 87/88, 88/89 and 89/90 agricultural seasons and measured data were compared with the data calculated by the model. In order to understand how each parameter affects the results of the model and the importance of their accurate measurement, sensitivity analyses were performed. / Pour améliorer le fonctionnement des systèmes d'irrigation il faut une compréhension appropriée de l'interaction entre les canaux d'irrigation et de drainage et le système d'aquifères. Une plus grande difficulté réside dans le fait que ce mécanisme doit être étudié d'une façon suffisamment détaillée pour réussir à identifier des règles opérationnelles pour des secteurs spécifiques d'un système d'arrosage et de drainage. A cet égard les modèles numériques représentent une aide convenable du moment que par ce chemin des procédés opérationnels spécifiques de canaux d'irrigation et de drainage peuvent être évalués

Water resources and sustainability challenges in the globalized oases of Mendoza, Argentina

International audienc

Contaminación por fosfatos en el oasis bajo riego del río Mendoza .

International audienc

SIMGRO, a GIS-Supported Regional Hydrologic Model in Irrigated Areas : Case study in Mendoza, Argentina

The SIMGRO hydrologic simulation model was extended to include irrigation practice. It could then be used to evaluate the effect of hydrologic changes in an irrigated area in the province of Mendoza, Argentina where, given an average annual rainfall of approximately 200mm , irrigation is crucial for agriculture. A storage dam was recently constructed in the Mendoza River to control the fluctuating river flow and to guarantee that the demand for water is met throughout the year. The dam will impact on parts of the irrigation system where groundwater levels are already high and salinization occurs. To evaluate these changes and possible mitigation measures, two performance indicators that consider groundwater and surface water were used: Relative evapotranspiration and the depleted fraction. Scenario runs revealed that the irrigation water losses from the canals affect the groundwater levels in the downstream part of the irrigated area; an increase in salinity was also reveale

Calidad del agua de riego de los ríos Mendoza y Tunuyán superior. Tendencias y recomendaciones

International audienc

Cooperation on Water management issues, Argentina : Project in the framework of Bilateral Cooperation between Argentina and the Netherlands : Case studies on water management issues in Argentina

In Argentina parts of the country have problems encountered from too much water or suffer serious water shortages. The Humid Pampas encounter an increased rainfall since the 1970’s. In Mendoza Province water resources are limited and all the water from the rivers is used for agriculture, drinking water and industries. For the management of such systems an integrated approach is needed, where hydrological modelling tools can be used to support decision making