An economic modelling approach for vulnerability assesment in irrigation farms in Spain

In the last years, vulnerability assessment has emerged as a need for policy making instead of being a pure academic exercise (Hinkel, 2010). In the current context of changing climate, increasing water scarcity threatens economic activities in many arid or semi-arid regions of the World. Climate change (CC) science and policy debates have traditionally focused on CC mitigation and impact assessment (Krysanova et al., 2010). However, even if mitigation policies are successfully enforced some climate change is still expected. Then, adaptation is strongly necessary and, for that, improved knowledge on vulnerability and adaptive capacity is required.

Alternative method for the metrological characterization of spur gears in the sub-millimeter range using optical equipment

The aim of this work is to develop a software that allows the inspection of spur gear manufactured in the sub-millimeter range. The measurements are made using a digital optical machine and using an analysis proprietary software implemented in Matlab®, which is able to handle images, captured using the digital optical machine. The software allows to evaluate the profile and pitch deviations as establish in the ISO/TR 10064-1:1992 standard

Use of DFOT Heat Pulse Method ForWetting Pattern Determination in Drip Irrigation Emitters

Although there are numerous accurate measuring methods to determine soil moisture content in a spot, until very recently there were no precise in situ and in real time methods that were able to measure soil moisture content along a line. By means of the Distributed Fiber Optic Temperature Measurement method or DFOT, the temperature in 0.12 m intervals and long distances (up to 10,000 m) with a high time frequency and an accuracy of +0.2º C is determined. The principle of temperature measurement along a fiber optic cable is based on the thermal sensitivity of the relative intensities of backscattered photons that arise from collisions with electrons in the core of the glass fiber. A laser pulse, generated by the DTS unit, traversing a fiber optic cable will result in backscatter at two frequencies. The DTS quantifies the intensity of these backscattered photons and elapsed time between the pulse and the observed returned light. The intensity of one of the frequencies is strongly dependent on the temperature at the point where the scattering process occurred. The computed temperature is attributed to the position along the cable from which the light was reflected, computed from the time of travel for the light.

Determination of suitable irrigation lengths and intervals using capacitance humidity sensors for a sandy soil

production, during the summer of 2010. This farm is integrated at the Spanish research network for the sugar beet development (AIMCRA) which regarding irrigation, focuses on maximizing water saving and cost reduction. According to AIMCRA 0 s perspective for promoting irrigation best practices, it is essential to understand soil response to irrigation i.e. maximum irrigation length for each soil infiltration capacity. The Use of Humidity Sensors provides foundations to address soil 0 s behavior at the irrigation events and, therefore, to establish the boundaries regarding irrigation length and irrigation interval. In order to understand to what extent farmer 0 s performance at Tordesillas farm could have been potentially improved, this study aims to address suitable irrigation length and intervals for the given soil properties and evapotranspiration rates. In this sense, several humidity sensors were installed: (1) A Frequency Domain Reflectometry (FDR) EnviroScan Probe taking readings at 10, 20, 40 and 60cm depth and (2) different Time Domain Reflectometry (TDR) Echo 2 and Cr200 probes buried in a 50cm x 30cm x 50cm pit and placed along the walls at 10, 20, 30 and 40 cm depth. Moreover, in order to define soil properties, a textural analysis at the Tordesillas Farm was conducted. Also, data from the Tordesillas meteorological station was utilized.

Optimization of the irrigation time and irrigation frequency by using Hydrus-2D and a capacitance FDR sensor

The evolution of water content on a sandy soil during the sprinkler irrigation campaign, in the summer of 2010, of a field of sugar beet crop located at Valladolid (Spain) is assessed by a capacitive FDR (Frequency Domain Reflectometry) EnviroScan. This field is one of the experimental sites of the Spanish research center for the sugar beet development (AIMCRA). The objective of the work focus on monitoring the soil water content evolution of consecutive irrigations during the second two weeks of July (from the 12th to the 28th). These measurements will be used to simulate water movement by means of Hydrus-2D. The water probe logged water content readings (m3/m3) at 10, 20, 40 and 60 cm depth every 30 minutes. The probe was placed between two rows in one of the typical 12 x 15 m sprinkler irrigation framework. Furthermore, a texture analysis at the soil profile was also conducted. The irrigation frequency in this farm was set by the own personal farmer 0 s criteria that aiming to minimizing electricity pumping costs, used to irrigate at night and during the weekend i.e. longer irrigation frequency than expected. However, the high evapotranspiration rates and the weekly sugar beet water consumption—up to 50mm/week—clearly determined the need for lower this frequency. Moreover, farmer used to irrigate for six or five hours whilst results from the EnviroScan probe showed the soil profile reaching saturation point after the first three hours. It must be noted that AIMCRA provides to his members with a SMS service regarding weekly sugar beet water requirement; from the use of different meteorological stations and evapotranspiration pans, farmers have an idea of the weekly irrigation needs. Nevertheless, it is the farmer 0 s decision to decide how to irrigate. Thus, in order to minimize water stress and pumping costs, a suitable irrigation time and irrigation frequency was modeled with Hydrus-2D. Results for the period above mentioned showed values of water content ranging from 35 and 30 (m3/m3) for the first 10 and 20cm profile depth (two hours after irrigation) to the minimum 14 and 13 (m3/m3) ( two hours before irrigation). For the 40 and 60 cm profile depth, water content moves steadily across the dates: The greater the root activity the greater the water content variation. According to the results in the EnviroScan probe and the modeling in Hydrus-2D, shorter frequencies and irrigation times are suggested.

Signal analysis and feature generation for pattern identification of partial discharges in high-voltage equipment

This paper proposes a method for the identification of different partial discharges (PDs) sources through the analysis of a collection of PD signals acquired with a PD measurement system. This method, robust and sensitive enough to cope with noisy data and external interferences, combines the characterization of each signal from the collection, with a clustering procedure, the CLARA algorithm. Several features are proposed for the characterization of the signals, being the wavelet variances, the frequency estimated with the Prony method, and the energy, the most relevant for the performance of the clustering procedure. The result of the unsupervised classification is a set of clusters each containing those signals which are more similar to each other than to those in other clusters. The analysis of the classification results permits both the identification of different PD sources and the discrimination between original PD signals, reflections, noise and external interferences. The methods and graphical tools detailed in this paper have been coded and published as a contributed package of the R environment under a GNU/GPL license.

Evapotranspiration and crop coefficients of rice (Oryza sativa L.) under sprinkler irrigation in a semiarid climate determined by the surface renewal method

The evapotranspiration (ETc) of sprinkler-irrigated rice was determined for the semiarid conditions of NE Spain during 2001, 2002 and 2003. The surface renewal method, after calibration against the eddy covariance method, was used to obtain values of sensible heat flux (H) from high-frequency temperature readings. Latent heat flux values were obtained by solving the energy balance equation. Finally, lysimeter measurements were used to validate the evapotranspiration values obtained with the surface renewal method. Seasonal rice evapotranspiration was about 750–800 mm. Average daily ETc for mid-season (from 90 to 130 days after sowing) was 5.1, 4.5 and 6.1 mm day−1 for 2001, 2002 and 2003, respectively. The experimental weekly crop coefficients fluctuated in the range of 0.83–1.20 for 2001, 0.81–1.03 for 2002 and 0.84–1.15 for 2003. The total growing season was about 150–160 days. In average, the crop coefficients for the initial (Kcini), mid-season (Kcmid) and late-season stages (Kcend) were 0.92, 1.06 and 1.03, respectively, the length of these stages being about 55, 45 and 25 days, respectively.

Summer deficit irrigation strategies in hedgerow olive orchard cv. ‘Arbequina’: Effect on fruit characteristics and yield.

Maximum production in hedgerow olive orchards is likely not achieved with maximum evapotranspiration over the long-term. Thus, regulated deficit irrigation (RDI) should be considered as a management option. Four irrigation treatments were evaluated during the summer when olive is most drought resistant. Control (CON) was irrigated to maintain the rootzone close to field capacity. Severe water deficit was applied by irrigating 30% CON from end of fruit drop to end July (DI-J) and from end July until beginning of oil synthesis (DI-A). Less severe water deficit was applied during July and August (DI-JA) by irrigating 50% CON. Flowering, fruiting, abscission, fruit development, fresh and dry weight of fruits, and oil production were evaluated. There were not significant differences in number of buds initiated, number of fruits per inflorescence and fruit drop. Oil production was significantly different between irrigation treatments in all experimental years. CON produced more oil and fruit with higher oil% than DI-A and DI-JA. Oil production of DI-J was not significantly reduced compared to CON and oil% was greater. DI-J was the most effective RDI strategy; with 16% less applied water relative to CON average loss in oil production of 8% was not significantly different to CON. While DI-JA saved most water (27%), oil production was reduced by 15%. Greatest loss in oil production (21%) was observed in DI-A with water saving of 22%.

Criterios para el dimensionamiento de redes de riego robustas frente a cambios en la alternativa de cultivos

En los años 50 y 60 del siglo XX se produjo en Europa un cambio en la concepción de los sistemas de riego, en los cuales se pasó del regadío por superficie al presurizado y con ello del riego por turnos al riego a la demanda. Las ventajas de este nuevo sistema de riego dieron lugar a una gran expansión de las redes colectivas de riego a presión, especialmente en los países del arco mediterráneo y del Sur de Europa (Francia, España, Italia, Portugal y Grecia). Desde entonces el riego presurizado a la demanda ha tenido una evolución permanente, en la que han mejorado los equipos y las técnicas de aplicación del riego, siempre con una clara orientación hacía el incremento de la productividad. Esta evolución unida a los vaivenes de los mercados, al abaratamiento de los transportes y la globalización, y a las subvenciones agrícolas, ha propiciado que las alternativas de cultivos previstas hayan sufrido cambios. El cambio de la alternativa de cultivos hacia otros más exigentes desde el punto de vista de las necesidades hídricas tiene como consecuencia el aumento de los consumos, circunstancia para cual debe estar capacitada la red. Otros fenómenos como el cambio climático, de amplio interés a día de hoy, presentan algunos escenarios en lo que se prevé un incremento de las temperaturas que unido a una reducción en las precipitaciones, supondría también que se elevarían las necesidades de riego de los cultivos. Todas estas circunstancias deben ser contempladas en la redacción de los proyectos de transformación de nuevas zonas regables y en los de modernización de las existentes. Las redes de riego deben estar dimensionadas para poder atender dichos incrementos de consumo. La fortaleza de la red para atender variaciones en las demandas de agua se convierte por tanto en una premisa del proyecto. Dicha fortaleza se puede conseguir de formas diferentes y a costos distintos, puesto que en el proceso de dimensionamiento estadístico de los caudales circulantes en punta de campaña intervienen muchas variables y parámetros de riego. En la presente tesis doctoral se analiza en detalle el estado del arte en la materia, se efectúa un análisis de la función específica y la influencia en el cálculo de cada uno de los parámetros, se establece un procedimiento de actuación que optimice el dimensionamiento de la red colectiva para que ésta disponga de la robustez necesaria para hacer frente a incrementos potenciales de consumo de agua sobre la previsiones de base del proyecto y se establecen los criterios, rangos y combinaciones de parámetros que permiten dotar a la red de la fortaleza necesaria de la manera más eficiente posible. During the 1950s and 1960s the design of irrigation systems in Europe underwent change. Traditional surface irrigation was replaced by pressure irrigation, with the delivery method shifting from a scheduled type to an on-demand one. The advantages obtained with this new system led to a significant development of on-demand pressurised irrigation districts, especially in the Southern countries (France, Greece, Italy, Portugal and Spain). On-demand pressurised irrigation has since evolved in a continuous manner in which, with the purpose of gaining productivity, on-farm equipment and automation instruments have seen improvements. Such developments, along with market fluctuations, reductions in transport costs, globalisation and the influence of agricultural subsidies, have resulted in changes in the crop pattern. The farming of new crops may require more water and the consumption may become greater. In addition to this, other phenomena, such as the frequently-debated effects of climate change, reveal scenarios in which an increase in temperatures and the accompanying reductions in rainfall are expected. One consequence of this would be an increase in irrigation requirements and subsequent impact on irrigation networks. All such circumstances should be taken into account in both the design of new irrigation districts and the upgrading of the existing ones. Irrigation networks should be of a size that allows them to meet increases in consumption. The robustness of the network, defined as its capacity to absorb increments in water requirements, becomes a key point to be taken into account in the design phase. Given that there are several parameters that influence the calculus of design flows, such robustness may be obtained in different ways and at varying costs. In the context of this, the thesis reviews the state of the art, analyses the role and influence of each parameter, establishes a procedure for checking the design and robustness of on-demand irrigation networks, and sets design criteria for selecting the most effective range and combination of parameters that provide the network with such robustness.

Criteria for Positioning Active Multilateration Stations Located Close to Distance Measuring Equipment

The need for the use of another surveillance system when radar cannot be used is the reason for the development of the Multilateration (MLT) Systems. However, there are many systems that operate in the L-Band (960-1215MHz) that could produce interference between systems. At airports, some interference has been detected between transmissions of MLT systems (1030MHz and 1090MHz) and Distance Measuring Equipment (DME) (960-1215MHz).

Non invasive moisture measurement in agricultural fiel using a rolling spherical robot

Irrigation management in large crop fields is a very important practice. Since the farm management costs and the crop results are directly connected with the environmental moisture, water control optimization is a critical factor for agricultural practices, as well as for the planet sustainability. Usually, the crop humidity is measured through the water stress index (WSI), using imagery acquired from satellites or airplanes. Nevertheless, these tools have a significant cost, lack from availability, and dependability from the weather. Other alternative is to recover to ground tools, such as ground vehicles and even static base stations. However, they have an outstanding impact in the farming process, since they can damage the cultivation and require more human effort. As a possible solution to these issues, a rolling ground robot have been designed and developed, enabling non-invasive measurements within crop fields. This paper addresses the spherical robot system applied to intra-crop moisture measurements. Furthermore, some experiments were carried out in an early stage corn field in order to build a geo-referenced WSI map.

Performance of pressure control valves and flow meters precision in operational irrigation-water balance accuracy

In pressure irrigation-water distribution networks, pressure regulating devices for controlling the discharged flow rate by irrigation units are needed due to the variability of flow rate. In addition, applied water volume is used controlled operating the valve during a calculated time interval, and assuming constant flow rate. In general, a pressure regulating valve PRV is the commonly used pressure regulating device in a hydrant, which, also, executes the open and close function. A hydrant feeds several irrigation units, requiring a wide range in flow rate. In addition, some flow meters are also available, one as a component of the hydrant and the rest are placed downstream. Every land owner has one flow meter for each group of field plots downstream the hydrant. Its lecture could be used for refining the water balance but its accuracy must be taken into account. Ideal PRV performance would maintain a constant downstream pressure. However, the true performance depends on both upstream pressure and the discharged flow rate. The objective of this work is to asses the influence of the performance on the applied volume during the whole irrigation events in a year. The results of the study have been obtained introducing the flow rate into a PRV model. Variations on flow rate are simulated by taking into account the consequences of variations on climate conditions and also decisions in irrigation operation, such us duration and frequency application. The model comprises continuity, dynamic and energy equations of the components of the PRV.

Pressurized Irrigation Dealing with Water and Energy Efficiencies

En la conferencia se expone la situación en España de los riegos a presión considerando los condicionantes de escasez de agua y el precio de la energía.

Energy requirements in pressure irrigation systems

Modernization of irrigation schemes, generally understood as transformation of surface irrigation systems into pressure –sprinkler and trickle- irrigation systems, aims at, among others, improving irrigation efficiency and reduction of operation and maintenance efforts made by the irrigators. However, pressure irrigation systems, in contrast, carry a serious energy cost. Energy requirements depend on decisions taken on management strategies during the operation phase, which are conditioned by previous decisions taken on the design project of the different elements which compose the irrigation system. Most of the countries where irrigation activity is significant bear in mind that modernization irrigation must play a key role in the agricultural infrastructure policies. The objective of this study is to characterize and estimate the mean and variation of the energy consumed by common types of irrigation systems and their management possibilities. The work includes all processes involved from the diversion of water into irrigation specific infrastructure to water discharge by the emitters installed on the crop fields. Simulation taking into account all elements comprising the irrigation system has been used to estimate the energy requirements of typical irrigation systems of several crop production systems. It has been applied to extensive and intensive crop systems, such us extensive winter crops, summer crops and olive trees, fruit trees and vineyards and intensive horticulture in greenhouses. The simulation of various types of irrigation systems and management strategies, in the framework imposed by particular cropping systems, would help to develop criteria for improving the energy balance in relation to the irrigation water supply productivity.

Summer deficit irrigation in a hedgerow olive orchard cv. Arbequina: relationship between soil and tree water status, and growth and yield components

El potencial hídrico del tronco es una herramiento útil para el manejo del riego. Los umbrales de riego deben establecerse para cada periodo fisiológico. En este experimento, realizado en Arbequina en seto, se estudio la relacion entre los potenciales hídricos y la produccion de aceite. Cuando los potenciales hidricos son inferiores a -1.3 MPa el crecimiento vegetativo se reduce mas del 50%. En cuanto a la produccion, se observó que regando en Julio cuando se alcanzan potenciales cercanos a -2.9 MPa se puede ahorrar agua sin afectar a la produccion. Sin embargo en Agosto el potencial debe mantenerse por encima de -2 MPa para que no se resienta la producción.