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1.
Precision irrigation involves the accurate and precise application of water to meet the specific requirements of individual
plants or management units and minimize adverse environmental impact. Under precision irrigation applications, water and associated
solute movement will vary spatially within the root zone and excess water application will not necessarily result in deep
drainage and leaching of salt below the root zone. This paper estimates that 10% of the irrigated land area (producing as
much as 40% of the total annual revenue from irrigated land) could be adversely affected by root zone salinity resulting from
the adoption of precision irrigation within Australia. The cost of increases in root zone salinisation due to inappropriate
irrigation management in the Murray and Murrumbidgee irrigation areas was estimated at AUD 245 million (in 2000/01) or 13.5%
of the revenue from these cropping systems. A review of soil–water and solute movement under precision irrigation systems
highlights the gaps in current knowledge including the mismatch between the data required by complex, process-based soil–water
or solute simulation models and the data that is easily available from soil survey and routine soil analyses. Other major
knowledge gaps identified include: (a) effect of root distribution, surface evaporation and plant transpiration on soil wetted
patterns, (b) accuracy and adequacy of using simple mean values of root zone soil salinity levels to estimate the effect of
salt on the plant, (c) fate of solutes during a single irrigation and during multiple irrigation cycles, and (d) effect of
soil heterogeneity on the distribution of water and solutes in relation to placement of water. Opportunities for research
investment are identified across a broad range of areas including: (a) requirements for soil characterisation, (b) irrigation
management effects, (c) agronomic responses to variable water and salt distributions in the root zone, (d) potential to scale
or evaluate impacts at various scales, (e) requirements for simplified soil–water and solute modelling tools, and (f) the
need to build skills and capacity in soil–water and solute modelling. 相似文献
2.
Standard precipitation index to track drought and assess impact of rainfall on watertables in irrigation areas 总被引:1,自引:0,他引:1
The Standard Precipitation Index (SPI) is employed to track drought and assess the impact of rainfall on shallow groundwater
levels in three selected irrigation areas of the Murray-Darling Basin in Australia. The continuous SPI method can provide
better means of quantifying rainfall variability and correlating it with changes of shallow watertable levels since it is
based on continuous statistical functions comparing rainfall variability over the entire rainfall record. Drought analysis
in the Australian irrigation areas using SPI indicates that the recent 2000–2006 drought is not the worst drought that has
occurred in the recorded history, however if the current low rainfall pattern continues, it would be one of the most prolonged
drought. The shallow groundwater fluctuations in the Murrumbidgee Irrigation Area show a very strong correlation with winter
rainfall variation. The shallow piezometric levels in the Coleambally Irrigation Area show a weaker degree of correlation
with the SPI due to local and regional groundwater dynamics and changes in rice water use. The groundwater levels in the Murray
Irrigation Area show least correlation with the SPI, which may be attributed to improved irrigation management practices and
complex nature of the groundwater recharge and discharge processes in this area. The overall results however show that the
SPI correlates well with fluctuations in shallow ground water table in irrigation areas, and can also capture major drought
patterns in Australia. The correlation of SPI with groundwater levels can be adopted for environmental reporting and used
as a method of relating climatic impacts on watertables. Differences in piezometric response between years with similar winter
and yearly SPI values can be attributed to improvement in irrigators’ management practices. 相似文献
3.
Irrigation reliability and the productivity of water: A proposed methodology using evapotranspiration mapping 总被引:1,自引:0,他引:1
Chris Perry 《Irrigation and Drainage Systems》2005,19(3-4):211-221
Irrigation is the dominant user of water worldwide, but provision of potable water and water for industry are higher priorities
and give higher social and economic returns. Irrigation will continue to lose water to competing sectors and the productivity
of irrigation systems (since food demand continues to grow) remains a central issue in water management. Performance assessment
of irrigation has traditionally been difficult when based on field measurements of flows, deliveries and depths over large
areas. Furthermore, performance measures have shifted from narrow engineering indicators to broader productivity issues of
production achieved per unit of water consumed. Remote sensing, applied to the estimation of evapotranspiration (ET) over
large areas, provides analysts of irrigation systems with extraordinary new tools for the objective assessment of consumption
and production – constituting a quantum leap in the assessment of irrigation system performance. Awareness and utilisation
of these tools is spreading, but important areas remain to be “converted” from traditional approaches that rely on an array
of estimated parameters. The next challenge for remote sensing will be to map the frontier between the reliability of the
irrigation service and the productivity achieved. Reliability provides the inducement for farmers to invest in higher productivity
– to the benefit of themselves and society – and understanding better how the individual maximises profits within an uncertain
irrigation environment can provide important guidance to managers and system designers. 相似文献
4.
The paper presents an analysis of the needs, strategies and means for training and research in irrigation. Some of the existing and proposed training programmes in irrigation and related fields are evaluated. The importance of enhancing professional skills of irrigation personnel through training and research, and of training farmers and communal leaders in water management skills for succesful irrigation is highlighted. The major concerns in future irrigation training and research are focused on social, economic and political issues which affect the basic tenets of efficiency and quality in irrigation water allocation and management. Action programmes to enhance both capabilities and investment in training and research in irrigation are proposed. 相似文献
5.
The management of water resources by orchards in the south-eastern region of Australia is an increasingly important policy
issue, especially given the low water allocations and concerns about salinity in recent years. Optimal management for economic
and environmental sustainability can be described as best management practice (BMP). A project was developed to run an extension
program, which aimed to achieve behavioural change among orchardists through the adoption of irrigation BMPs and benchmarks.
The effectiveness of the extension program was evaluated and the drivers for adoption assessed. In the first stage of the
project both BMPs and benchmarks were determined for irrigation management. A survey of 200 growers showed no relationship
between yield and irrigation system or irrigation volume suggesting that increased yields were not a key driver for adoption
of sustainable irrigation practices. Stage two of the project involved undertaking an extension program aimed to facilitate
the adoption of BMPs and benchmarks and incorporated a suite of activities to meet the learning needs of a diversity of participants
(40 growers). The program was effective in establishing behavioural change for many of the growers involved; however, it was
resource intensive requiring significant one-on-one input. Stage three aimed to analyse the key drivers for adoption of sustainable
irrigation practices for the whole of the stone and pome fruit industry in south-eastern Australia using market research.
The study determined that water use efficiency was not a key driver for adoption of sustainable irrigation practices (micro
irrigation and soil moisture monitoring) and adoption was generally not limited by lack of knowledge. Groups of growers were
identified where extension programs could be effective by focussing on specific information e.g. redevelopment of orchard.
Other groups had no need and/or ability to change unless the external operating environment was to change e.g. regulation,
access to pressurised water. The voluntary adoption of more sustainable irrigation practices will probably require extensive
resources using one-on-one methodology. The extension program should not focus on the broader social objective of improved
water use efficiency but promote other potential benefits (e.g. labour saving, redevelopment of production systems, management
flexibility) with targeted messages for specific groups. 相似文献
6.
为实现纵向岭谷区农业水管理调控,宏观上以流域水资源综合规划为基础,从需求入手,采取强化节水措施,提高水的利用效率,抑制需水的不合理增长,到2030年农田有效灌溉程度达到32%,灌溉水利用系数提高到0.581,农业灌溉需水总量控制在89.8亿m3,需水年均增长率仅0.52%,以MKIE BASIN模型的配置结果显示,各规划水平年能达到水资源供需平衡;微观上应建立数字流域工程,提高对流域雨水工情的实时监测.推行农业高效节水灌溉制度,建立和完善包括实时灌溉预报、渠系动态配水、实时信息采集和预报修正、灌区空间信息管理等内容的流域单元农业灌溉用水及水资源的实时调度系统,利用水资源配置成果与短期实时调度相结合,实现流域单元的农业高效用水调控. 相似文献
7.
The paper reports research on engineering designs of irrigation systems in mountainous areas and the resulting implications for management. The engineering designs are important because they may or may not provide the social basis for local people to participate in system development and management. This hypothesis is analyzed by using field data from an irrigation development program in the Himachal Pradesh State in India. The development program will construct about 150 small-scale, gravity flow and lift irrigation schemes in a seven year period. The results of the analysis support the argument that the engineering designs critically influence local people's capability and willingness to manage irrigation facilities. In gravity flow irrigation schemes, water capture by permanent flow diversion structuress is extremely expensive and yet unreliable because of large variation in stream flow and unstable mountain slopes. A more practical alternative is to utilize diversion structures of temporary nature which are made with local materials. Construction and management of such structures will encourage local participation because of high maintenance requirements. In lift irrigation schemes a conventional design is to lift all water requirements to a single highest point in the command area. This practice results in unnecessarily high energy costs and in a water distribution system which is complex to manage. A better alternative is to design the pumps so that water can be delivered at variable elevations in the scheme area. This will allow disaggregation of the total area into smaller rotational units and, therefore, management of water distribution can be potentially easier and equitable. 相似文献
8.
A modified checkbook irrigation method based on GIS-coupled model for regional irrigation scheduling
Xiaopeng Li Jiabao Zhang Jintao Liu Jianli Liu Anning Zhu Fei Lv Congzhi Zhang 《Irrigation Science》2011,29(2):115-126
In this study, a regional irrigation schedule optimization method was proposed and applied in Fengqiu County in the North
China Plain, which often suffers serious soil water drainage and nitrogen (N) leaching problems caused by excessive irrigation.
The irrigation scheduling method was established by integrating the ‘checkbook irrigation method’ into a GIS-coupled soil
water and nitrogen management model (WNMM) as an extension. The soil water and crop information required by the checkbook
method, and previously collected from field observations, was estimated by the WNMM. By replacing manually observed data with
simulated data from WNMM, the application range of the checkbook method could be extended from field scale to regional scale.
The WNMM and the checkbook irrigation method were both validated by field experiments in the study region. The irrigation
experiment in fluvo–aquic soil showed that the checkbook method had excellent performance; soil water drainage and N leaching
were reduced by 83.1 and 85.6%, respectively, when compared with local farmers’ flood irrigation. Using the validated WNMM,
the performance of checkbook irrigation in an entire winter wheat and summer maize rotation was also validated: the average
soil water drainage and N leaching in four types of soils decreased from 331 to 75 mm year−1 and 47.7 to 9.3 kg ha−1 year−1, respectively; and average irrigation water use efficiency increased from 26.5 to 57.2 kg ha−1 mm−1. The regional irrigation schedule optimization method based on WNMM was applied in Fengqiu County. The results showed a good
effect on saving irrigation water, decreasing soil water drainage and then saving agricultural inputs. In a typical meteorological
year, it could save >110 mm of irrigation water on average, translating to >7.26 × 107 m3 of agricultural water saved each year within the county. Annual soil water drainage was reduced to <143 mm and N leaching
to <27 kg ha−1 in most soils, all of which were significantly lower than local farmers’ flood irrigation. In the mean time, crop yield also
had an average increase of 2,890 kg ha−1 when checkbook irrigation was applied. 相似文献
9.
Klaartje Vandersypen Abdoulaye C. T. Keita Bruno Lidon Dirk Raes Jean-Yves Jamin 《Irrigation and Drainage Systems》2008,22(1):103-113
In many irrigation schemes, Water Users Associations (WUAs) acquired the responsibility for water management after withdrawal
of the state. Based on the success of some indigenous irrigation schemes, it was assumed that farmers could easily become
managers. As decision-making was the exclusive terrain of the governmental agencies that ran the schemes, farmers never gained
the necessary experience with water management. Therefore, training of farmers and WUAs on the principles and processes of
water management is essential. This paper demonstrates a practical example of training material on water management that incorporates
research results on the process of Irrigation Management Transfer and resulting farmers’ water management for the case of
the Office du Niger irrigation scheme. The results of the paper explain how input from research was used in the four steps
of the construction of training material. These steps are (1) setting the training agenda, (2) selecting and adapting information
to be featured, (3) targeting the audience and (4) designing the actual training material. A first validation of the approach
and examples of the actual training material were obtained in a workshop uniting all stakeholders. 相似文献
10.
W. Wolters Nadi Selim Ghobrial H. M. Van Leeuwen M. G. Bos 《Irrigation and Drainage Systems》1989,3(2):103-123
A study of the water balances of The Fayoum irrigated lands and Lake Qarun was made to investigate the management of the irrigation
system and the efficiency of irrigation water use. The two water balances are strongly interrelated. The drainage flow to
Lake Qarun and the water level of the Lake are in delicate balance. A rise in Lake level causes the inundation of adjacent
land. Management of The Fayoum water balance assumes control over irrigation water flows, but this control has technical and
organizational limitations.
Also discussed is the influence of irrigation practices in The Fayoum on the water balance (e.g., the autumn flushing of fields
and farmers' preference for not irrigating at night in winter).
Notwithstanding a high overall efficiency, irrigation efficiency during the winter is low. The reasons for this are given,
together with the constraints against improving system management.
Improved uniformity of the division and application of irrigation water will enable a better technical control of flows and
will result in better water management in The Fayoum.
Abbreviations: FID — Fayoum Irrigation Department, 1 feddan (fe) — 0.4 ha, 1 mcm — 1 million cubic metres: an average annual flow of 3.17
m3/s gives 100 mcm, m3/fe.year — supplied volume (m3) per surface area (fe) per year: 1000 m3/fe.year equals 240 mm/year, MSL — Mean Sea Level 相似文献
11.
Recent community based actions to ensure the sustainability of irrigation and protection of associated ecosystems in the Murrumbidgee Irrigation Area (MIA) of Australia has seen the implementation of a regional Land and Water Management Plan. This aims to improve land and water management within the irrigation area and minimise downstream impacts associated with irrigation. One of the plan objectives is to decrease current salt loads generated from subsurface drainage in perennial horticulture within the area from 20 000 tonnes/year to 17 000 tonnes/year. In order to meet such objectives Controlled Water table Management (CWM) is being investigated as a possible ‘Best Management Practice’, to reduce drainage volumes and salt loads.During 2000–2002 a trial was conducted on a 15 ha subsurface drained vineyard. This compared a traditional unmanaged subsurface drainage system with a controlled drainage system utilizing weirs to maintain water tables and changes in irrigation scheduling to maximize the potential crop use of a shallow water table. Drainage volumes, salt loads and water table elevations throughout the field were monitored to investigate the effects of controlled drainage on drain flows and salt loads.Results from the experiment showed that controlled drainage significantly reduced drainage volumes and salt loads compared to unmanaged systems. However, there were marked increases in soil salinity which will need to be carefully monitored and managed. 相似文献
12.
L. McClymont I. Goodwin M. Mazza N. Baker D. M. Lanyon A. Zerihun S. Chandra M. O. Downey 《Irrigation Science》2012,30(6):461-470
Spatial variation in yield and fruit composition has been observed in many vineyards, leading to low productivity. In this study, site-specific irrigation was applied in a commercial vineyard (Vitis vinifera L. cv. Shiraz) block in the Sunraysia region of Australia to improve production in low-yielding areas of the block and decrease differences in yield and quality between irrigation management zones. Data collected under uniform irrigation management showed that spatial variation in canopy cover, yield and fruit composition across the vineyard block was substantial. Normalised difference vegetation index (NDVI) and canopy temperature data supported delineation of three irrigation management zones and decisions regarding irrigation strategy. Water use efficiency and yield improvements were achieved by implementing site-specific irrigation. Fruit composition results were varied; pH and titratable acidity showed increased similarity between zones, but other parameters maintained differences between zones. These results lend support to the use of NDVI to determine irrigation management zones. 相似文献
13.
文章为了使教育信息化技术与高等教育更深度的融合,在线下教育不能够有效进行的条件下,通过分析“数控单元实训”课程所面临的问题,并进行研讨实训教学实际、讨论解决方案到最终实施,提出了特殊条件下可以采用“多媒体课件+实训课程视频+虚拟仿真软件”的混合式教学方法,形成了实训课程线上教学的科学思路,保证了高校学生未返校期间实训教学任务有条不紊的推进,顺利完成了本学期工程实训教学计划,有效解决了工程实训线上教学中遇到的各种问题。 相似文献
14.
Water resources and water use efficiency in the North China Plain: Current status and agronomic management options 总被引:6,自引:0,他引:6
Serious water deficits and deteriorating environmental quality are threatening agricultural sustainability in the North China Plain (NCP). This paper addresses spatial and temporal availability of water resources in the NCP, identifies the effects of soil management, irrigation timing and amounts, and crop genetic improvement on water use efficiency (WUE), and then discusses knowledge gaps and research priorities to further improve WUE. Enhanced irrigation and soil nutrient (mainly nitrogen) management are the focal issues in the NCP for enhancing WUE, which are shown to increase WUE by 10-25% in a wheat-maize double cropping system. Crop breeding has also contributed to increased of WUE and is expected to play an important role in the future as genetic and environmental interactions are understood better. Agricultural system models and remote sensing have been used to evaluate and improve current agronomic management practices for increasing WUE at field and regional scales. The low WUE in farmer's fields compared with well-managed experimental sites indicates that more efforts are needed to transfer water-saving technologies to the farmers. We also identified several knowledge gaps for further increasing WUE in the NCP by: (1) increasing scientific understanding of the effects of agronomic management on WUE across various soil and climate conditions; (2) quantifying the interaction between soil water and nitrogen in water-limited agriculture for improving both water and nitrogen-use efficiency; (3) improving irrigation practices (timing and amounts) based on real-time monitoring of water status in soil-crop systems; and (4) maximizing regional WUE by managing water resources and allocation at regional scales. 相似文献
15.
英语学术论文写作是研究生培养过程中必不可少的环节,如何提高硕士研究生的英语学术论文写作能力是高校英语教学中亟待解决的难题。近些年来众多高校纷纷开设相关课程,虽然取得了长足的发展,但仍然缺乏对导致农业工程学科硕士研究生英语学术论文写作能力不高原因的系统分析。结合农业工程类硕士研究生专业特色,以提高硕士研究生英语学术论文写作能力为目标,从研究生、导师和高校3个方面深入分析了研究生英语学术论文写作存在的主要问题,并提出解决对策,以期构建农业工程学科硕士研究生英语学术论文写作能力培养模式。 相似文献
16.
Prasanna H. Gowda Jose L. Chavez Paul D. Colaizzi Steve R. Evett Terry A. Howell Judy A. Tolk 《Irrigation Science》2008,26(3):223-237
Evapotranspiration (ET) is an essential component of the water balance. Remote sensing based agrometeorological models are
presently most suited for estimating crop water use at both field and regional scales. Numerous ET algorithms have been developed
to make use of remote sensing data acquired by sensors on airborne and satellite platforms. In this paper, a literature review
was done to evaluate numerous commonly used remote sensing based algorithms for their ability to estimate regional ET accurately.
The reported estimation accuracy varied from 67 to 97% for daily ET and above 94% for seasonal ET indicating that they have
the potential to estimate regional ET accurately. However, there are opportunities to further improving these models for accurately
estimating all energy balance components. The spatial and temporal remote sensing data from the existing set of earth observing
satellite platforms are not sufficient enough to be used in the estimation of spatially distributed ET for on-farm irrigation
management purposes, especially at a field scale level (∼10 to 200 ha). This will be constrained further if the thermal sensors
on future Landsat satellites are abandoned. However, research opportunities exist to improve the spatial and temporal resolution
of ET by developing algorithms to increase the spatial resolution of reflectance and surface temperature data derived from
Landsat/ASTER/MODIS images using same/other-sensor high resolution multi-spectral images. 相似文献
17.
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19.
Summary Fine textured soils (> 40% clay) form a major proportion of irrigated soils in northeastern Australia. More than half these soils are irrigated with groundwater, some of which has high salinity (electrical conductivity > 2.9 mS cm–1). A simple prediction of salt leaching was sought to aid in land management decisions.An empirical model of leaching fraction is presented based on rainfall and easily measured soil properties related to hydraulic conductivity. The model is based on data from 766 soils. To account for the complexity of interactions between soil properties, the data was stratified into groups based on clay content and mineralogy (expressed here as CEC/clay ratio). This allowed simple linear regressions using ESP and rainfall to be developed to predict leaching fraction.When applied to irrigated soils, a salinity correction term (ECrain+irrigation/ECrain) was used to account for the flocculation effects of the increased salinity of irrigation waters. The model gave good predictions of leaching fraction for two irrigation regions with widely differing soil properties (Fig. 4). 相似文献
20.
Integrating satellite-based evapotranspiration with simulation models for irrigation management at the scheme level 总被引:2,自引:2,他引:0
Improvements in irrigation management are urgently needed in regions where water resources for irrigation are being depleted.
This paper combines a water balance model with satellite-based remote-sensing estimates of evapotranspiration (ET) to provide
accurate irrigation scheduling guidelines for individual fields. The satellite-derived ET was used in the daily soil water
balance model to improve accuracy of field-by-field ET demands and subsequent field-scale irrigation schedules. The combination
of satellite-based ET with daily soil water balance incorporates the advantages of satellite remote-sensing and daily calculation
time steps, namely, high spatial resolution and high temporal resolution. The procedure was applied to Genil–Cabra Irrigation
Scheme of Spain, where irrigation water supply is often limited by regional drought. Compared with traditional applications
of water balance models (i.e. without the satellite-based ET), the combined procedure provided significant improvements in
irrigation schedules for both the average condition and when considering field-to-field variability. A 24% reduction in application
of water was estimated for cotton if the improved irrigation schedules were followed. Irrigation efficiency calculated using
satellite-based ET and actual applied irrigation water helped to identify specific agricultural fields experiencing problems
in water management, as well as to estimate general irrigation efficiencies of the scheme by irrigation and crop type. Estimation
of field irrigation efficiency ranged from 0.72 for cotton to 0.90 for sugar beet. 相似文献