452 research outputs found
Effects of the decoupling of the subsidies on agricultural water productivity
Get PDFIn this work several performance indicators such as the Annual Relative Irrigation Supply (ARIS) and the Irrigation Water Productivity (IWP), have been considered to evaluate the changes in the cotton irrigation management due to the decoupling of the European Union Subsidies. For this purpose, a modern irrigation scheme, the Genil–Cabra Irrigation Scheme (GCIS) located in Southern Spain, has been selected. The total irrigated area is 6,900 ha with wheat, olive and cotton as the main crops. The irrigation season 2004/05 was the period when the crop pattern and water management trend changed dramatically. From this year to the present the area cultivated with crops with high water requirements like cotton, sugar beet and maize has been reduced almost by half, while the area with low irrigation requirement crops (winter cereals, sunflower or olive) has increased of 37%. After the decoupling of the EU cotton subsidies in 2006, the cotton agricultural practices have changed toward a less intensive production system, including both, lower water application (ARIS for cotton decreased from values higher than 0.8 to 0.5 in the irrigation season 2006/07) and less agrochemical usage. In terms of sustainability, the reform has increased the cotton irrigation efficiency (IWP for cotton increased from around 0.7 €/m3 to 1.0 €/m3 in the irrigation season 2006/07) and has reduced its environmental impact.CAP Subsidies, Irrigation, Arable Crops, Spain, Agricultural and Food Policy, Resource /Energy Economics and Policy,
Measurements of turbulence at stratocumulus top
No full textUsing 1m resolution airborne data from research flights we divide stratocumulus top region into sublayers and characterize properties of turbulence in each sublayer. Results indicate, that there are no clear differences of turbulence properties between thermodynamically different "calassical" and "non-classical" stratocumulus regimes, but there are clear signs of turbulence ainsotropy in stably stratified sublayers in the cloud top region
Effects of the EU agricultural subsidies on the irrigation management in Spain. The case of a modern irrigation scheme
No full textThe decoupling of the subsidies due to the Mid-Term Review of the CAP has affected the use of inputs in general and the irrigation applied in particular for sugar beet and cotton. In the last case, the elimination of the intervention price and the subsequent lowering of the producers’ selling price have resulted in an extensification of the production with yields 40% lower than the average. From the environmental point of view the reform has increased the cotton irrigation efficiency and it has therefore moved the crop practices toward a more sustainable production systemEl desacoplamiento de las ayudas resultado de la Reforma Intermedia de la PAC, junto a la disminución en la disponibilidad de agua ha tenido una influencia importante en el uso de insumos en general y en el manejo del agua de riego en particular. Este impacto es especialmente claro en los casos del algodón y de la remolacha, cuyas menores aplicaciones de insumos se han traducido en incrementos en los rendimientos cercanos al 40%. Este menor uso de insumos supone a su vez el cambio en los sistemas de producción tradicionales hacia sistemas con menor impacto medioambiental y, por tanto, con mayores garantías de sostenibilidad.</p
Effects of the EU agricultural subsidies on the irrigation management in Spain
Get PDFThe decoupling of the subsidies due to the Mid-Term Review of the CAP has affected the use of inputs in general and the irrigation applied in particular for sugar beet and cotton. In the last case, the elimination of the intervention price and the subsequent lowering of the producers selling price have resulted in an extensification of the production with yields 40% lower than the average. From the environmental point of view the reform has increased the cotton irrigation efficiency and it has therefore moved the crop practices toward a more sustainable production systemEl desacoplamiento de las ayudas resultado de la Reforma Intermedia de la PAC, junto a la disminución en la disponibilidad de agua ha tenido una influencia importante en el uso de insumos en general y en el manejo del agua de riego en particular. Este impacto es especialmente claro en los casos del algodón y de la remolacha, cuyas menores aplicaciones de insumos se han traducido en incrementos en los rendimientos cercanos al 40%. Este menor uso de insumos supone a su vez el cambio en los sistemas de producción tradicionales hacia sistemas con menor impacto medioambiental y, por tanto, con mayores garantías de sostenibilidad.</p
Effects of the decoupling of the subsidies on agricultural water productivity
Get PDFIn this work several performance
indicators such as the Annual Relative Irrigation Supply
(ARIS) and the Irrigation Water Productivity (IWP),
have been considered to evaluate the changes in the
cotton irrigation management due to the decoupling of
the European Union Subsidies. For this purpose, a
modern irrigation scheme, the Genil–Cabra Irrigation
Scheme (GCIS) located in Southern Spain, has been
selected. The total irrigated area is 6,900 ha with wheat,
olive and cotton as the main crops. The irrigation season
2004/05 was the period when the crop pattern and water
management trend changed dramatically. From this
year to the present the area cultivated with crops with
high water requirements like cotton, sugar beet and
maize has been reduced almost by half, while the area
with low irrigation requirement crops (winter cereals,
sunflower or olive) has increased of 37%. After the
decoupling of the EU cotton subsidies in 2006, the cotton
agricultural practices have changed toward a less
intensive production system, including both, lower water
application (ARIS for cotton decreased from values
higher than 0.8 to 0.5 in the irrigation season 2006/07)
and less agrochemical usage. In terms of sustainability,
the reform has increased the cotton irrigation efficiency
(IWP for cotton increased from around 0.7 €/m3 to 1.0
€/m3 in the irrigation season 2006/07) and has reduced
its environmental impact
Application-oriented link adaptation for IEEE 802.11
No full textThe thesis addresses the ever-persistent problem of quality guarantees in wireless data networks. The quality guarantees are especially important for real-time streaming applications. While in fixed links most of the quality issues could be, and are still resolved by over-provisioning, in the world of wireless communications things get complicated. The main reason for wireless links being a bottleneck in terms of both achievable throughput and packet loss and delay guarantees, is the resource limitation that will always be there. Our work showed that while there is no magic solution that can resolve all link quality-related problems in wireless networks, a lot could be done to mitigate them. The first, and the most important, is to make the radio as adaptive to the changes of the link conditions as possible. This can be done through our advanced hybrid rate-control algorithm. The algorithm combines a stable throughput-based solution with a rapid link-quality feedback supplement into a novel controller that has both swift response and stable performance. The second solution, which is dependant on the first one, is the propagation of link status-related information from the link layer to the application. The latter can use this feedback to change its data stream properties to match those of the underlying wireless link. This behaviour proves most useful in cases when the radio cannot compensate for a deterioration of the radio connection such as a significant drop of the signal strength due to obstruction, or too many users competing to use the same medium.Electrical Engineering, Mathematics and Computer Scienc
Co-creatie in het publieke domein: Een vanzelfsprekendheid
No full textIndustrial DesignIndustrial Design Engineerin
Estimating actual irrigation application by remotely sensed evapotranspiration observations
No full textWater managers and policy makers need accurate estimates of real (actual) irrigation applications for effective monitoring of irrigation and efficient irrigation management. However, this information is not readily available at field level for larger irrigation areas. An innovative inverse modeling approach was tested for a field in an irrigation scheme in southern Spain where observed actual evapotranspiration by satellites was used to assess irrigation application amounts. The actual evapotranspiration was used as the basis for an optimization procedure using the physical based SWAP model and the parameter optimization tool PEST. To evaluate the proposed techniques two steps were taken. First, actual observed evapotranspiration from remote sensing was used to optimize two parameters of the SWAP model to determine irrigation applications. Second, a forward-backward approach was applied to test the minimum overpass return time of satellites and the required accuracy of remotely sensed actual evapotranspiration for accurate assessment of irrigation applications. Results indicate that irrigation application amounts can be estimated reasonably accurately, providing data are available at an interval of 15 days or shorter and the accuracy of the signal is 90% or higher.Irrigation Spain Cotton Remote sensing SWAP PEST FutureWater
Bubble velocity measurements using ultrasound
No full textApplied SciencesKramers Laboratorium voor Fysische Technologi
Experimental study on tranisitio characteristics of natural-concvection flow
No full textApplied Science
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