Modelling the potential of rainwater harvesting to improve the sustainability of landscape and public garden irrigation.

Access to water for irrigating amenity landscape and public gardens is under intense pressure due to the rising competition for water between different sectors, exacerbated by increased drought risk and climate change. Rainwater harvesting (RWH) has the potential to reduce the economic impacts of restrictions on irrigation abstraction in dry years and to build resilience to future water shortages. This study investigated the hydrological viability of RWH for the landscape and public garden sector based on an analysis of five Royal Horticultural Society gardens. A RWH model was developed and combined with on-site observations, key informant interviews and GIS analyses, to estimate irrigation demands and the volumes of harvested rainfall for contrasting agroclimatic years. The results showed that gardens located in wetter regions and with low irrigation water demand to harvestable area ratio had a higher RWH potential and could almost exclusively rely on rainwater to meet irrigation demand, even in dry years. RWH potential is more limited for gardens in drier regions where they would require larger areas to harvest rainwater and for storage. Appropriately designed rainwater harvesting systems offer the potential to remove most of the risk of irrigation abstraction restrictions during dry years and associated impacts on amenity planting quality and visitor experience.

Computational fluid dynamics in root canal irrigation.

Root canal irrigation is an important step in root canal preparation procedures and has a great impact on the success rate of root canal treatment. Computational fluid dynamics (CFD) is a new method to study root canal irrigation. It can be used to simulate and visualize the process of root canal irrigation, and quantitatively evaluate the effect of root canal irrigation through parameters such as flow velocity and wall shear stress. In recent years, researchers have conducted extensive studies on the factors that influence root canal irrigation efficiency, such as the position of the irrigation needle, the size of root canal preparation, the types of irrigation needles, and so on. This article reviewed the development of root canal irrigation research methods, the steps of CFD simulation in root canal irrigation, and the application of CFD in root canal irrigation in recent years. It aimed to provide new research ideas for the application of CFD to root canal irrigation and to provide a reference for the clinical application of CFD simulation results.

Assessment of Irrigation Efficiency by Coupling Remote Sensing and Ground-Based Data: Case Study of Sprinkler Irrigation of Alfalfa in the Saratovskoye Zavolgie Region of Russia.

Nowadays, the leading role of data from sensors to monitor crop irrigation practices is indisputable. The combination of ground and space monitoring data and agrohydrological modeling made it possible to evaluate the effectiveness of crop irrigation. This paper presents some additions to recently published results of field study at the territory of the Privolzhskaya irrigation system located on the left bank of the Volga in the Russian Federation, during the growing season of 2012. Data were obtained for 19 crops of irrigated alfalfa during the second year of their growing period. Irrigation water applications to these crops was carried out by the center pivot sprinklers. The actual crop evapotranspiration and its components being derived with the SEBAL model from MODIS satellite images data. As a result, a time series of daily values of evapotranspiration and transpiration were obtained for the area occupied by each of these crops. To assess the effectiveness of irrigation of alfalfa crops, six indicators were used based on the use of data on yield, irrigation depth, actual evapotranspiration, transpiration and basal evaporation deficit. The series of indicators estimating irrigation effectiveness were analyzed and ranked. The obtained rank values were used to analyze the similarity and non-similarity of indicators of irrigation effectiveness of alfalfa crops. As a result of this analysis, the opportunity to assess irrigation effectiveness with the help of data from ground and space-based sensors was proved.

Can deficit irrigations be an optimum solution for increasing water productivity under arid conditions? A case study on wheat plants.

Water scarcity is of growing concern in many countries around the world, especially within the arid and semi-arid zones. Accordingly, rationalizing irrigation water has become an obligation to achieve the sustainable developmental goals of these countries. This may take place via using deficit irrigation which is long thought to be an effective strategy to save and improve water productivity. The current study is a trial to evaluate the pros and cons of using 50 and 75 % of the irrigation requirements (IR) of wheat (deficit irrigations) versus 100 %IR, while precisely charting changes in wheat growth parameters, antioxidant enzymes in plant shoots and the overall nutritional status of plants (NPK contents). Accordingly, a field experiment was conducted for two successive seasons, followed a split-plot design in which deficit irrigations (two irrigations to achieve 50 % of the irrigations requirements (IR), three irrigations to attain 75 % IR, and four irrigations to fulfill 100 % IR) were placed in main plots while four different studied wheat cultivars were in subplots. Results obtained herein indicate that deficit irrigations led to significant reductions in growth parameters and productivity of all wheat cultivars, especially when using 50 % IR. It also decreased NPK contents within plant shoots while elevated their contents of proline, peroxidase, and catalase enzymes. On the other hand, this type of irrigation decreased virtual water content (VWC, the amount of water used in production on ton of wheat grains). Stress tolerance index (STI), and financial revenues per unit area were also assessed. The obtained values of grain productivity, STI, VWC and financial revenues were weighted via PCA analyses, and then introduced in a novel model to estimate the efficiency of deficit irrigations (ODEI) whose results specified that the overall efficiency decreased as follows: 50 %IR < 75 %IR < 100 %IR. In conclusion, deficit irrigation is not deemed appropriate for rationalizing irrigation water while growing wheat on arid soils.

A novel irrigation device with superior nasal irrigation efficiency to the classic rinse bottle.

BACKGROUND: The ability of saline irrigation to detach the mucous and the flow-limiting effect of the nasal valve has not been well explored. The objective of this study was to compare the removal efficiency of a novel irrigation device with an extended nozzle versus a classic rinse bottle. METHODS: Transparent casts of the unoperated sinonasal cavity were made by 3D printing. Yogurt was used to simulate mucous. The cast filled with 5 ml yogurt was fixed in six head positions and irrigated with 120 ml, 175 ml, and 240 ml dyed water through the novel device and the rinse bottle. The irrigation efficiency was the ratio of the weight of yogurt washed away divided by the total weight of yogurt. RESULTS: The irrigation stream of a long nozzle with a side opening was different from the irrigation stream of the outlet within the nasal vestibule. The novel devices presented with continuous water stream directly upwards to the anterior part of the olfactory cleft. Depending on different head positions, it was easy for the novel devices to achieve an irrigation efficiency of 100% when the cast was irrigated with 120 ml or 175 ml water. There was still a tiny amount of yogurt left in the olfactory cleft when the cast was irrigated with 240 ml water under each head position for the rinse bottle. The irrigation efficiency was volume-dependent, and the average irrigation efficiency of the rinse bottle at 240 ml only reached 69.1%. CONCLUSIONS: The novel irrigation device presented with superior nasal irrigation efficiency to the classic rinse bottle. A continuous water stream directly upwards to the anterior part of the olfactory cleft combined with an extended nozzle overcoming the flow-limiting effect of the nasal valve promotes nasal irrigation efficiency.

Uniformity of water distribution by a sprinkler irrigation system on a soccer field

Soccer field grass can be compared to highly sensitive crops regarding water deficit and must be irrigated throughout the year to provide decent conditions for use. For this, efficient irrigation systems are necessary to save water and energy, and this is possible, provided that they are evaluated. Therefore, this paper evaluated the water distribution uniformity, by different methodologies, for an irrigation system installed in a grass soccer field. Also, the influences of multiple spacings between sprinklers and meteorological factors on the final results were assessed. The irrigation system had Falcon 6504 sprinklers, operating at the pressure of 320 kPa. Six field essays were conducted considering overlaying water depths originated from the same irrigation system considering spacings between sprinklers varying from 6 m x 6 m, 6 m x 9 m, 9 m x 9 m, 9 m x 12 m, 12 m x 12 m, 12 m x 15 m, 15 m x 15 m, 15 m x 18 m, 18 m x 18 m, 18 m x 21 m, 21 m x 21 m, 21 m x 24 m, 24 m x 24 m, 24 m x 27 m, 27 m x 27 m, 27 m x 30 m and 30 m x 30 m. The uniformity coefficients used were: Christiansen uniformity coefficient (CU), distribution uniformity coefficient (DU), absolute uniformity coefficient (UA), statistical uniformity coefficient (US), Hart uniformity coefficient (UH) and HSPA standard efficiency (UHSPA). Meteorological data were obtained during the essays. Wind speed caused reduction in the length of the water jet applied by the sprinkler and also caused a bigger effect on the water distribution uniformity. Both CU and UH showed higher values compared to the other coefficients. The increase in the spacing between the sprinklers resulted in reduced water distribution coefficients. To comply with technical and economic criteria, an arrangement of 12 m x 15 m between the Falcon 6504 sprinklers, operating at a 320 kPa pressure, is recommended.

Development of an apparatus and procedure for evaluating the efficiency of nasal irrigation.

BACKGROUND: Although different methods of nasal irrigation have been utilized, irrigation efficiency in nasal cavities has not been well assessed. The objective of this study was to develop an apparatus and procedure for evaluating the irrigation efficiency and to explore the optimal head position during irrigation. METHODS: Casts of the left sinonasal cavity from a healthy volunteer were made from high-resolution-computed tomography data using 3D printing with composite materials. An adjustable apparatus that allowed cast fixation at the different head positions was built. The yogurt was used to simulate mucus. The cast with 5 ml yogurt filled around the superior, middle, and inferior turbinate was fixed in six head positions including head tilt 10°, 45°, and 60° forward with or without leaning 30° to the right. The cast was irrigated with 120 ml, 175 ml, and 240 ml dyed water and was video recorded. The irrigation efficiency was calculated based on the weight difference of the cast before and after the irrigation. RESULTS: Most residual yogurt was located around the superior meatus after the irrigation under different volumes and head positions. The irrigation efficiency of the rinse bottle or the pulsatile device was volume dependent, with the highest irrigation efficiency under 240 ml water. When the left sinonasal cavity was irrigated, the head position of tilt 45° forward with leaning 30° to the right was the optimal head position for these two devices when compared to other positions. The pulsatile device with 240 ml water performed better than the rinse bottle with 240 ml water regarding the irrigation efficiency under the optimal head position (0.8700 ± 0.0138 vs 0.7536 ± 0.0099, p = 0.003). CONCLUSIONS: The developed apparatus provided a potential method for evaluating the irrigation efficiency. The head position of tilt 45° forward with leaning 30° was suitable for patients to perform the nasal irrigation.

Assessing the potential for renewable energy powered desalination for the global irrigation sector.

By 2050, it is estimated that the annual cereal production would need to increase by about 140% and total global food production increase by 70%. Meanwhile, total water withdrawals for irrigation are projected to increase by 11%. In contrast, poor management of existing water resources, pollution and climate change has resulted in limited freshwater resources. The aim of this paper is to assess how improved irrigation efficiency and renewable energy based desalination maybe used to secure future water supplies for the growth of rice, wheat and maize. The efficiencies of the existing irrigation sites were obtained and improved based on a logistic curve. The growth was projected such that by 2050, all existing irrigation sites would have an efficiency of 90%. The new irrigation efficiencies were used to obtain the reduced irrigation demand for the years 2030 and 2050. The desalination demand was estimated and an energy system model used to optimise the corresponding renewable energy based power system. It was found that improving the average irrigation efficiency to 60% by 2030, led to a 64% reduction in total desalination demand. Similarly, an improvement towards 90% irrigation efficiency, by 2050, translates to an 80% reduction in global desalination demand. In 2030, the total water cost is mostly within 0.7 €/m3-2 €/m3 including water transportation costs. Literature reports that farmers may be willing to pay up to 0.63 €/m3 for their irrigation water. The global range in 2050 is estimated to be 0.45 €/m3-1.7 €/m3 reflecting the lower system costs in 2050. The above results indicate that as conventional water prices increase, renewable energy based seawater reverse osmosis desalination, offers a cost effective water supply for the irrigation sector. Adoption of high efficiency irrigation systems alleviate water stress and can eliminate need for additional water supply.

Adaptation of land management in the Mediterranean under scenarios of irrigation water use and availability.

Meeting the growing demand for food in the future will require adaptation of water and land management to future conditions. We studied the extent of different adaptation options to future global change in the Mediterranean region, under scenarios of water use and availability. We focused on the most significant adaptation options for semiarid regions: implementing irrigation, changes to cropland intensity, and diversification of cropland activities. We used Conversion of Land Use on Mondial Scale (CLUMondo), a global land system model, to simulate future change to land use and land cover, and land management. To take into account future global change, we followed global outlooks for future population and climate change, and crop and livestock demand. The results indicate that the level of irrigation efficiency improvement is an important determinant of potential changes in the intensity of rain-fed land systems. No or low irrigation efficiency improvements lead to a reduction in irrigated areas, accompanied with intensification and expansion of rain-fed cropping systems. When reducing water withdrawal, total crop production in intensive rain-fed systems would need to increase significantly: by 130% without improving the irrigation efficiency in irrigated systems and by 53% under conditions of the highest possible efficiency improvement. In all scenarios, traditional Mediterranean multifunctional land systems continue to play a significant role in food production, especially in hosting livestock. Our results indicate that significant improvements to irrigation efficiency with simultaneous increase in cropland productivity are needed to satisfy future demands for food in the region. The approach can be transferred to other similar regions with strong resource limitations in terms of land and water.

Application of water footprint combined with a unified virtual crop pattern to evaluate crop water productivity in grain production in China.

Water shortages are detrimental to China's grain production while food production consumes a great deal of water causing water crises and ecological impacts. Increasing crop water productivity (CWP) is critical, so China is devoting significant resources to develop water-saving agricultural systems based on crop planning and agricultural water conservation planning. A comprehensive CWP index is necessary for such planning. Existing indices such as water use efficiency (WUE) and irrigation efficiency (IE) have limitations and are not suitable for the comprehensive evaluation of CWP. The water footprint (WF) index, calculated using effective precipitation and local water use, has advantages for CWP evaluation. Due to regional differences in crop patterns making the CWP difficult to compare directly across different regions, a unified virtual crop pattern is needed to calculate the WF. This project calculated and compared the WF of each grain crop and the integrated WFs of grain products with actual and virtual crop patterns in different regions of China for 2010. The results showed that there were significant differences for the WF among different crops in the same area or among different areas for the same crop. Rice had the highest WF at 1.39 m(3)/kg, while corn had the lowest at 0.91 m(3)/kg among the main grain crops. The WF of grain products was 1.25 m(3)/kg in China. Crop patterns had an important impact on WF of grain products because significant differences in WF were found between actual and virtual crop patterns in each region. The CWP level can be determined based on the WF of a virtual crop pattern, thereby helping optimize spatial distribution of crops and develop agricultural water savings to increase CWP.

Parâmetros de desempenho de dezesseis equipamentos de irrigação por pivô central / Parameters of performance of sixteen center-pivot irrigation equipments

O tempo de uso de sistemas de irrigação por pivô central pode resultar em alteração de suas características hidráulicas, necessitando de avaliações periódicas para manter a uniformidade de distribuição de água em níveis aceitáveis. Objetivou-se, neste trabalho, avaliar as condições de funcionamento e desempenho de dezesseis pivôs centrais, localizados em onze municípios de Goiás e no Distrito Federal. Estimou-se o coeficiente de uniformidade de Heermann & Hein - CUH e uniformidade de distribuição - CUD, variação da lâmina coletada em relação à projetada e os fatores que interferem no desempenho dos equipamentos. Dos pivôs avaliados, quatro (25 por cento) apresentaram CUH inadequado (< 80 por cento) e três (18,75 por cento) apresentaram CUD inadequado (< 70 por cento). A lâmina média coletada foi superior à projetada em três e inferior em treze pivôs, com diferença maior que 10 por cento em apenas um pivô. A maioria dos pivôs avaliados necessita de manutenção para solucionar algum dos seguintes problemas: bocais com vazão diferente da considerada adequada para alguns intervalos dos equipamentos, emissores total ou parcialmente obstruídos ou danificados, ausência de pendurais, reguladores de pressão danificados, vazamentos em vários pontos da lateral e velocidade de deslocamento em campo diferente da indicada no relé porcentual.

The time of use of the center-pivot irrigation system may result in alteration of the hydraulic characteristics, frequent evaluations being needed to maintain the efficiency of water distribution at acceptable levels. The aim of this work was to evaluate the conditions of the use and the performance of sixteen center pivots, located in eleven municipal districts of Goiás State and Federal District, Brazil. The Heermann & Hein - CUH coefficient of uniformity and coefficient of distribution - CUD, variation between the collected and projected depth and verification of the main factors that influenced the performance were evaluated. Among the evaluated pivots, four (25 percent) presented inadequate CUH (< 80 percent) and three (18.75 percent) presented inadequate CUD (< 70 percent). The average depth applied was higher than the projected in three and lower in thirteen pivots, with the difference higher than 10 percent in only one pivot. Most of the evaluated pivots need maintenance to solve the following problems: emitters with flow rate different from the flow considered appropriate for some intervals of the equipments; emitters totally or partially clogged or damaged; absence of suspension strings; damaged pressure regulators; leaks in several points and speed displacement different from the observed on the relay percentile.

Root zone sensors for irrigation management in intensive agriculture.

Crop irrigation uses more than 70% of the world's water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower's experience or on the determination of soil water balance (weather-based method). An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS), such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS' (for both soil moisture and salinity) marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy) on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.