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1.
Modern analysis of surface irrigation systems with WinSRFR 总被引：5，自引：0，他引：5
E. Bautista A.J. Clemmens T.S. Strelkoff J. Schlegel 《Agricultural Water Management》2009,96(7):1146-1154
WinSRFR is a new generation of software for analyzing surface irrigation systems. Founded on an unsteady flow hydraulic model, the software integrates event analysis, design, and operational analysis functionalities, in addition to simulation. This paper provides an overview of functionalities, interface, and architectural elements of the software, and discusses technical enhancements in version 2.1, released in late 2007, and version 3.1, scheduled for release in 2009. 相似文献
2.
畦灌灌水技术要素组合优化 总被引：7，自引：0，他引：7
以杨凌区进行的畦灌大田试验为基础,采用WinSRFR软件对各试验点的灌水质量进行了模拟,并分析了畦长、田面坡度、入畦单宽流量和改口成数对灌水效率Ea、灌水均匀度Ed和储水效率Es的影响;在此基础上,结合均匀试验设计与多元回归分析的方法,构建了包含灌水效率Ea、灌水均匀度Ed和储水效率Es在内的单目标优化模型,以入畦单宽流量和灌水时间为变量,采用遗传算法对模型进行求解,提出了试验点不同计划灌水深度条件下畦灌灌水技术要素的优化组合,结果表明其可获得高的灌水质量,达到常规畦灌节水的目的。 相似文献
3.
传统畦灌模型多是基于非恒定渐变流方程建立的,在模拟变流量畦灌水流运动时的精度难以保障。本文综合分析了变流量畦灌过程中田面水流的运动状况,将其按照边界条件的不同划分为恒定流量进水阶段、变流量进水阶段、畦首消退阶段、田面消退第1阶段、田面消退第2阶段等5个阶段,基于非恒定渐变流方程和非恒定急变流方程构建了适用于变流量畦灌系统的渐变流-急变流数值模型,通过2组恒定流量畦灌、4组变流量畦灌的田间试验以及2组文献资料中的畦灌试验数据对模型进行了验证。结果表明,渐变流-急变流畦灌模型模拟值与现场实测结果吻合较好,模拟推进时间决定系数R2均大于0.96、模拟消退时间R2大于0.90。与目前常用的WinSRFR模型相比,渐变流-急变流畦灌数值模型在模拟恒定流量畦灌方面具有相似的精度,且在模拟变流量畦灌方面精度更高。渐变流-急变流畦灌模型可以较精准地模拟变流量畦灌的水流运动状况,可为分析变流量畦灌系统、优化变流量畦灌方案提供支撑。 相似文献
4.
Higher performance through combined improvements in irrigation methods and scheduling: a discussion 总被引：2，自引：0，他引：2
Luis S. Pereira 《Agricultural Water Management》1999,40(2-3):153-169
Prior to the discussion on approaches to combine irrigation scheduling and water application practices, several farm irrigation performance indicators are defined and analysed. These indicators concern the uniformity of water distribution along an irrigated field and the efficiency of on-farm water application. Then, the analysis focus is on three main irrigation systems: surface, sprinkler and microirrigation. For each of these systems, the analysis concerns the main characteristics and constraints of the systems, more relevant aspects influencing irrigation performances, and approaches which could lead to a more appropriate coupling of irrigation scheduling and water application methods. Conclusions point out on the need for combined improvements in irrigation scheduling and methods, for expanding field evaluation of irrigation in farmers fields, for improved design of on-farm systems, and for quality control of irrigation equipments and design. 相似文献
5.
Luciano Mateos David Lozano Oumar Abdoul Diallo Jordi Comas 《Agricultural Water Management》2010,97(6):901-1152
During the last quarter of the 20th century, many irrigation schemes were constructed along the bank of the Senegal River in Mauritania. About 40,000 ha were developed but less than 23,000 ha remain irrigated today. A program for rehabilitation is now in place to counteract deterioration and abandonment of these schemes. This paper presents an evaluation of the rehabilitation of a small, representative irrigation scheme governed by a farmers’ cooperative in the village of Bélinabé. Before rehabilitation, the scheme covered 37.7 ha comprising 107 plots each of 0.33 ha, essentially all devoted to production of rice. Water for irrigation was pumped directly from the river into two head basins and distributed through open canals. After rehabilitation, the scheme was extended to 115 ha with new plots averaging 0.36 ha. Water is now supplied by a single cluster of pumps and conveyed through pipes and open canals. Evaluation of performance consisted in analysis of: capacity; distribution losses; flexibility, adequacy and reliability of the system; maintenance status; farmer's perception of system performance. Field data were collected during irrigation campaigns before rehabilitation in 2004 and during 2006 and 2007 afterwards. A model of network distribution and field water balance was developed to assist evaluation. It was established that before rehabilitation the scheme could operate satisfactorily if proper maintenance were practiced. After rehabilitation, more families have access to irrigation but reliability and flexibility of water distribution have been reduced. Furthermore, pumping capacity is now insufficient to cover crop water requirements. Recommendations are provided for future rehabilitation work and maintenance of schemes generally. 相似文献
6.
Basin irrigation design with longitudinal slope 总被引：1，自引：0，他引：1
César González Luis CerveraDavid Moret-Fernández 《Agricultural Water Management》2011,98(10):1516-1522
The aims of this paper are to analyze theoretically the influence of the longitudinal slope of a surface irrigation field on the uniformity of irrigation and to provide practical tools to design, analyze and manage surface irrigation systems with longitudinal slope and blocked end. An example is shown where a 20% savings in water is obtained by giving the field the optimal slope.In 1982, Clemmens and Dedrick published a practical set of dimensionless graphs to level-basin design and analysis (with no slope). This article generalizes those graphs taking account the existence of field slope. So, Clemmens and Dedrick's graphs are a particular case of obtained results.The analysis is based on solving one-dimensional free surface Saint-Venant equations including infiltration, applying the dimensional analysis to reduce the number of variables involved. Saint-Venant equations are solved with the finite differences method, applying the full hydrodynamic model and the zero-inertia model. Two computer programs are used: WinSRFR and POZAL (a specific software that calculates the optimal cutoff time).The result is a set of three-dimensional graphs that show the relationships of field slope, irrigation uniformity and the rest of the involved dimensionless variables, related to infiltration parameters, Manning roughness coefficient, cutoff time, inflow rate and field length and width. The graphs could be useful in practice to determine the optimal slope of a field, the inflow rate or the length and width of a field, achieving substantial savings of water in surface irrigation. 相似文献
7.
基于WinSRFR软件的河套灌区水平畦田规格的优化 总被引：1，自引：0，他引：1
为了提升河套灌区的土地资源与灌水质量,以大田水平畦灌试验水流推进与消退实测数据为基础,采用数值模拟和分析方法,对河套灌区现状畦田规格进行优化设计.通过WinSRFR软件系统设计功能,基于田间各灌水要素,采用水量平衡法计算灌水质量指标并采用零惯量模拟率定.模拟出不同畦田规格组合的灌水质量指标等值线图,确定了满足灌水要求并具有较高灌水质量的灌溉系统的优化范围,考虑土地权属与畦田规格现状,提出了典型田块设计方案.方案1:合并田-毛渠-田,畦长为102 m、畦宽为65~95 m,畦田面积为6 670 ~10 005 m2.方案2:合并田-毛渠-田-路-田,畦长为154 m、畦宽为65~110 m,畦田面积为10 005 ~16 675 m2. 相似文献
8.
Usefulness and limitations of decision support systems for improving irrigation scheme management 总被引：1，自引：0，他引：1
David Lozano 《Agricultural Water Management》2008,95(4):409-418
SIMIS (the FAO Scheme Irrigation Management Information System) is a decision support system that integrates tools and performance indicators to facilitate the planning and management of irrigation schemes. The authors used SIMIS to compute performance indicators in an irrigation scheme in Southern Spain that were used to identify distribution system constraints affecting the flexibility of water deliveries and to identify scheme sectors where deliveries could not meet the predicted crop water demands. Applying SIMIS, the authors and the irrigation scheme manager evaluated measures to overcome the constraints for future irrigation campaigns, and to refine the water orders made every 2 weeks to the basin authority. On the other hand, SIMIS presented limitations to the evaluation of on-demand delivery schedules. To overcome these limitations, an external model, developed outside SIMIS, showed that the current distribution network of the scheme has the capacity to deliver water on-demand only if a slight water deficit is accepted during the peak demand period. The analysis showed that by relaxing the stringency of the quality of operation of on-demand systems, rotation systems may be transformed into on-demand systems without changing their structures. This analysis could also be done using Clément's hypothesis, but doing so resulted in overestimates of the quality of operation and of the relative irrigation supply. 相似文献
9.
M.J. Calejo 《Agricultural Water Management》2008,95(2):154-162
On-demand pressurized irrigation systems are designed to deliver water with the flow rate and pressure required by the farm irrigation systems, sprinkling or micro-irrigation, and respecting the time, duration and frequency decided by the farmers. Due to the variation in farm demand along the season and the day, a large spatial and temporal variability of flow regimes occurs in these systems, which may affect the performance of the farm systems and the yields of the irrigated crops. Therefore, there is a need to analyse those systems to identify and solve performance problems. In this research, two simulation models for the analysis of irrigation systems operating on-demand, ICARE and AKLA, are used and compared to assess the hydraulic performance of the irrigation network of the Lucefecit Irrigation System, in Southern Portugal. ICARE assesses the global performance of the irrigation system through the indexed characteristic curves, while AKLA provides for the identification of the relative pressure deficit and reliability at every hydrant. Both models adopt a flow-driven analysis approach, performing the analysis for multiple flow regimes. To support the hydraulic characterization of the system and for calibration of the steady-state hydraulic model, field measurements were performed at selected nodes of the network, including four hydrants. The analysis with ICARE does not provide for a sufficient identification of problems. In fact, poor performance is indicated when a few hydrants operate below the minimum pressure set at design. Differently, the analysis with AKLA, applied at the hydrant level, shows that the performance of the Lucefecit system is generally acceptable. AKLA identifies which hydrants operate below the required pressure and, therefore, allows to support any eventual related improvement. Results show that the performance of the system highly improved when changing the piezometric elevation from 260 to 265 m a.s.l. However, this improvement is not sufficient because three hydrants still have high relative pressure deficit and low reliability. Solutions for those hydrants require increasing diameters of network pipes supplying them. 相似文献
10.
11.
Jens Erik Ørum Mads Vejlby Boesen Søren Marcus Pedersen 《Agricultural Water Management》2010,98(3):465-471
Drip irrigation systems and irrigation strategies like deficit irrigation (DI) and partial root drying (PRD) are potential water saving irrigation systems and strategies. This paper analyses the Serbian farmer's economic incentive to use these water saving systems and strategies instead of the present sprinkler irrigation. The analysis is a partial budgeting analysis, based on irrigation application efficiency from the literature, standard figures for power requirements, pumping efficiency and friction losses for various sources of water and pressure requirements, yields and water use from recent Serbian field experiments, as well as prices and cost structures for potatoes collected in the Belgrade region. The analysis shows that changing the present system and strategy can save a significant amount of water (almost 50%). At the same time, however, irrigation costs are also significantly increased (more than doubled), and the total production costs are increased by 10% (deficit drip irrigation) and 23% (PRD). Increased taxes on water, investment subsidies, increased energy prices, and an increased yield or yield quality may provide incentives for farmers to change to new systems and strategies. The analysis indicates that a 0.80 to 1.97 € m−3 water tax is needed to make deficit drip irrigation and PRD profitable. The socioeconomic cost of providing water for irrigation and the alternative value of saved water are probably not that high. Thus, water taxation may not be a socioeconomic efficient means to improve the irrigation water productivity of Serbian potato production. Drip irrigation and PRD may, however, also increase the yield quality, and a 10-23% quality premium (price increase) is needed to make deficit drip irrigation and PRD profitable. 相似文献
12.
在华北引黄灌区内,大田作物的主要灌溉方式依然是畦灌。由于畦田规格过长过宽,导致灌溉水浪费严重,灌水效率低下。在平原县张庄管道灌溉示范区进行畦田灌溉试验,研究了黄河下游引黄灌区不同灌水技术参数组合对灌水质量的影响。利用地面灌溉水流运动的计算机模拟软件WinSRFR4.1,对不同规格畦田的灌水过程进行模拟,得出畦田灌溉的田间灌水效率和灌水均匀度,研究不同灌水技术参数组合对灌水质量的影响。综合考虑管道灌溉出水口规格与当地耕作农具尺寸等因素,模拟了多种畦长、畦宽、坡度和单宽流量下灌溉方案的灌水效果,结果表明,畦宽1.5m,畦长50~60m,坡度为0.3%畦田灌溉技术改进方案的灌水效率和灌水均匀度均提高到80%以上,灌水性能较优,建议在黄河下游引黄灌区内推广使用。 相似文献
13.
The decision support system (DSS) MIRRIG has been developed to support the design of microirrigation systems and to advise farmers as a result of field evaluations. It is written in Visual Basic 6.0, runs in a Windows environment, and uses a database with information on emitters and pipes available in the market, as well as on crops, soils and the systems under design. MIRRIG is composed by design and simulation models and a multicriteria analysis model that ranks alternative design solutions based upon an integration of technical, economic and environmental criteria. User friendly windows are adopted for handling the databases and to manage the sub-models. The model allows creating and comparing a set of design alternatives relative to the pipe system and the emitters, either drip or microsprinkling emitters. For each alternative, the pipe system is sized and the irrigation system is simulated to produce performance, environmental and economic indicators. These include uniformity of water application, potential for contamination with agrochemicals due to water percolation, and installation and operation costs. Those indicators are used as attributes of the selected criteria. All alternatives are then compared and ranked through multicriteria analysis where the weights giving the relative importance of the adopted criteria are defined by the user. These procedures allow selecting the best design alternative and solving the complexities involved in the design of microirrigation systems. The model is available from the website www://ceer.isa.utl.pt/cms or by contacting cpedras@ualg.pt. 相似文献
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15.
This paper evaluates the performance of the first drip irrigation scheme in commercial tea production in Tanzania with a view
to making recommendations for improved management and providing data for investment decisions. Uniformity, efficiency and
adequacy of irrigation were calculated and the scheduling of irrigation water was reviewed. Operators were interviewed to
highlight the main benefits and problems of the system. Investment and recurrent costs of drip and overhead sprinkler systems
were quantified and compared. Root development was assessed qualitatively using excavation pits. Irrigation uniformity DU and efficiency ranged between 88 and 95% in the 10 out of 14 irrigation blocks where endline pressures were at least 0.5
bars, and between 77 and 89% in the four blocks were endline pressure was less than 0.5 bars. Scheduling drip irrigation using
tensiometers offered potential water savings of 26% in comparison to a water balance schedule, but these are not currently
realised. Gross marginal income was very sensitive to tea price and yield. Economically optimal fertilizer rates vary in dependence
of tea price and yield and appear to be lower than the current level of 300 kg N ha−1. The higher costs under drip, compared to overhead sprinklers, were mainly for purchase and installation and fertilizer.
The costs of labour for applying water and fertilizer were reduced by nearly 50%. At average 2002 tea prices of 1.31 US$ kg−1, drip irrigation would improve the grower’s gross margin if an additional yield of at least 411 kg ha−1 was achieved. The main threats to drip system performance are discussed. Future research efforts should aim at establishing
the yield response of tea to water and fertilizer under drip irrigation. 相似文献
16.
乌中灌区是贵州省的大型灌区之一,灌区工程多修建于上世纪50至70年代。至今,大多渠道老化难以正常工作,渠系老化率平均达0.55;灌区有效灌溉面积锐减,现状有效灌溉面积为设计灌溉面积的37%-54%,其中改种占相当比例;灌溉水利用系数较低,在0.39—0.42之间。本文以5个典型样点灌区为例,分析渠系老化对农田灌溉的影响。 相似文献
17.
种植盆栽需要科学合理的浇灌方式。为此,设计了基于微控制器的浇灌装置。该装置充分考虑了给植物浇灌各种主要因素,如季节、水温等,采用了传感器、加热部件、继电器等检测控制部件。该装置在硬件平台上移植了嵌入式操作系统,更好地实现了多任务调度。虽然本装置是基于盆栽的小型浇灌系统,但也可以用于大规模的浇灌系统,具有很强的推广性。 相似文献
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19.
On-farm measurements and observations of water flow, water costs and irrigation labour inputs at the individual parcel level
were made in case studies of smallholder irrigation systems in sub-Saharan Africa and south-eastern Arabia. The systems, in
which the water source supplied either single or multiple users, were analysed to address the fundamental issues of labour
allocation for on-farm water management as this has important consequences for the success of such systems. Results show that
the costs associated with accessing water influenced labour input, because when they were low the farmers tended to increase
the irrigation rate and reduce the amount of time they spent distributing the water within their parcels. Conversely when
water costs were high, lower flow rates and more time spent in water distribution were observed, and this resulted in more
uniform irrigation and higher irrigation efficiency. Also, opportunities and demands for farmers to use their labour for activities
other than irrigation can lead them to modify operational or physical aspects of the system so that they can reduce the time
they spend distributing water within the parcels, particularly when the water is relatively cheap. Awareness and better understanding
of how farmers may allocate their labour for water management will lead to more effective planning, design and management
of smallholder irrigation systems. 相似文献
20.
Subsurface drip irrigation of processing tomatoes is increasing in California. The common design approach is to bury drip
lines 0.2–0.36 m deep in the middle of the plant row, which places drip lines directly beneath plant rows. This design limits
the use of the drip irrigation system to only those crops compatible with this drip line and bed spacing, and thus, other
design approaches are being investigated to increase the flexibility of the drip systems. These approaches are installing
drip lines in alternate furrows and installing drip lines in every furrow, both of which place drip lines midway between plant
rows. The furrows are the result of the cultural practices used to form beds for planting.This study investigated the effect
of the different drip line placements on crop yield and quality. Results showed that the highest yields occurred for the buried
placement and the smallest yields for the alternate furrow placement. For the buried placement, soil water content and root
density were concentrated around the drip lines, directly beneath the plant rows, while for the furrow placements, zones of
high soil water content and root density did not coincide with the plant rows. However, some growers have found the furrow
placement to reduce some of the disease problems normally experienced with the traditional furrow irrigation methods. 相似文献