河北平原农业灌溉水质监测评价

为及时掌握灌溉农业水环境的状况及变化趋势,参照农田灌溉水质评价标准,分流域选取11个监测项目,对农业灌溉水质进行了连续2年的监测,采用污染指数法对监测结果进行评价。结果表明,除个别灌溉水质存在单项超标外,地表灌溉水、地下灌溉水水质的综合污染指数均小于1。总体而言,地表灌溉水、地下灌溉水水质完全符合农业灌溉水水质要求,灌溉用水是安全、可靠的。     

联邦德国农业灌溉水质标准综述

无论国内外,农业灌溉用水均占有较大比重,水量一般可以通过工程措施等综合技术措施加以解决,但要使灌溉水完全达到作物要求的水质标准却相对很困难,因为生活和工业污染源对各种用途的循环水的污染,在未给予充分稀释后灌溉农作物常发生危害,因而要求制定农业灌溉水质标准。     

我国田间灌溉技术节水效果比较

田间灌溉技术是提高灌溉水利用率的最后环节,也是农业节水的重点环节。大力发展田间节水灌溉技术是提高我国农业用水效率,维持农业可持续发展的重要措施。从水分利用效率及灌溉水利用效率的角度对不同田间灌水技术的节水效果进行比较分析,认为提高田间灌溉水的利用率研究应以减少灌溉水的损失为中心,通过多种田间农业节水技术的优化配置,形成一整套综合的由节水栽培、节水灌溉、节水管理有机结合的田间节水技术体系,促进我国农业节水事业的发展。     

灌溉水利用系数分析及其影响因素探讨

我国是一个水资源匮乏的国家,随着经济增长速度的加快,水资源短缺问题严重制约着我国农业的发展。为了有效地解决农业可持续用水问题,大力发展节水灌溉技术成为必然。因此,研究灌溉水利用系数和其影响因素意义重大。基于我国灌溉水利用系数测算分析方法,结合文成县灌溉水利用现状,建立了"首尾测算法"灌溉利用系数计算模型,并综合分析了灌区规模、灌溉类型、管理水平对灌溉系数的影响,希望为今后农业高效灌溉技术的发展提供帮助。     

渭北地区农村灌溉水环境存在问题及对策

水资源浪费和水质污染是造成当前农村灌溉水环境恶化的重要原因,本文结合东雷抽黄合阳灌区灌溉中的实际情况提出相应的对策和解决办法.可供相关单位参考.     

渭北地区农村灌溉水环境存在问题及对策

水资源浪费和水质污染是造成当前农村灌溉水环境恶化的重要原因,本文结合东雷抽黄合阳灌区灌溉中的实际情况提出相应的对策和解决办法.可供相关单位参考.     

基于水资源总量控制的灌溉面积动态分析

采用现状统计与水利普查分析修正、用水比例、水土平衡综合法分析表明,干旱新疆区地方系统,农业用水占总供水量93%和90%时,2020年灌溉面积为423.1和409.7×104hm2,相当于达到灌溉水利用系数0.52及综合毛灌溉定额9 075 m3/hm2水平;2030年灌溉面积为470.5和454.8×104hm2,相当于达到灌溉水利用系数0.57及综合毛灌溉定额8 355 m3/hm2水平,分析指出,降低灌溉定额、提升灌溉水利用系数和农业高效节水规模,是稳定和推进灌溉面积的技术保障。     

灌溉水对土壤污染的影响及防治措施

通过对土壤及污染灌溉水组成的分析,指出污染灌溉水对土壤所造成的危害,并通过分析灌溉水污染的特点,提出了解决因灌溉水而造成污染的具体措施。     

农业灌溉水利用系数分析方法及运用实践微探

农业灌溉水利用系数是一种可评价灌溉节水效率、节水潜力等的指标,其对农业节水和水资源的合理利用具有积极的意义。在实际的农业灌溉水利用系数运用中,需要对具体的分析方法进行掌握,确保运用效果。故此,展开对农业灌溉水利用系数分析方法的简单分析,并对几种方法的比较和测算类型等进行阐述,再结合实例,对农业灌溉水利用系数运用进行阐述,旨在综合提升农业节水效率、发挥节水潜力,推动农业持续健康发展。     

灌溉水中盐分对土壤结构性质及水流运动特征的影响

再生水和微咸水等用于农田灌溉对缓解农业用水紧缺、保证粮食稳产高产方面作用显著。但这些非常规灌溉水中的盐分进入受灌农田土壤会引起土壤结构性质的改变,进而引起入渗水流运动特征的变化,增大了农业灌水和施肥的管理难度及地下水受污染的风险。本文通过室内灌水入渗试验,研究了灌溉水盐分浓度(0、1.0、3.0和5.0 g/L)、灌水频率(1天1次、2天1次、4天1次)、含盐灌溉水-清水交替灌溉模式(纯清水灌溉、纯含盐灌溉水灌溉、含盐灌溉水-清水交替灌溉)对受灌土壤容重、团聚体结构稳定性、孔隙结构特征、地表入渗性能以及入渗水流运动非均匀特征的影响。结果表明,适度的盐分浓度、较低的灌水频率但较大的灌水定额、含盐灌溉水-清水交替灌溉均有利于提升土壤团聚体的稳定性、抑制土壤板结、改善受灌土壤的地表入渗性能、降低入渗水流运动的非均匀性。研究成果对再生水和微咸水农田灌溉制度设计具有参考价值。     

黄河流域灌溉农业节水技术模式及发展对策

针对黄河流域灌溉农业的特点，分别对渠灌区、井灌区、井渠结合灌区、机电提水灌区、集雨灌溉、城郊灌溉、抗旱灌溉等提出了各自的灌溉农业节水技术模式，并指出黄河流域灌溉农业节水发展应加强对黄河水资源的统一规划、调度和管理，必须建立稳定高效的投入保障机制，制定鼓励管理机构发展灌溉农业节水的政策。依靠科技创新促进灌溉用水方式的改革，推进农业经济结构调整和改革传统的农业生产方式。     

A New Model for Simulating Supplemental Irrigation and the Hydro-Economic Potential of a Rainwater Harvesting System in Humid Subtropical Climates

Here we have developed a new model to simulate supplemental irrigation and the hydro-economic potential of a rainwater harvesting system in rainfed agricultural areas. Using the model, soil moisture in rainfed crop land, supplemental irrigation requirements, rainwater storage in an on-farm reservoir (OFR) system, and surface and ground water availability were predicted. In an irrigated system, an OFR was used to harvest rainwater during the rainy season, and stored water was applied to cropland as supplemental irrigation (SI). An economic analysis was performed to calculate the benefits due to an OFR irrigation system, and gains from increased crop yield and downstream water availability in the irrigated OFR system were compared with rainfed system (i.e. no OFR). In addition, we calculated the impacts of dry and wet seasons on total value gains (grain and water gains) for irrigated and rainfed conditions and performed a sensitivity analysis to quantify the impacts of model input parameters on total value gains. Analyses showed that the OFR system can produce crop yields three times greater than rainfed agriculture. During a water stress season, the total water use in the irrigated system was 65 % greater than for the rainfed system. Water use efficiency of the irrigated system was 82 % higher than for the rainfed system. In a dry season, the total value gains due to increased crop yield by supplemental irrigation and downstream water availability of the irrigated system were 74 % greater than for the rainfed system, while in a wet season the total value gain of the irrigated system was 14 % greater than for the rainfed system. A precipitation scenario analysis of wet and dry seasons indicated that the benefits of a rainwater harvesting system can be considerably greater in dry seasons than wet seasons.     

Policy Options to Improve Water Allocation Efficiency: Analysis on Egypt and Morocco

Abstract

Because of political risk, economic feasibility, and cultural concerns, it has been a great challenge for economists to provide palatable remedies to governments to promote water allocation efficiency. Considering the limitation of water pricing to irrigation water, this research addresses questions of which strategic policy alternatives to water pricing might improve irrigation water allocation efficiency. An empirical framework is provided to compare irrigation policies for allocating scarce water to agricultural production in Egypt and Morocco. Partial-equilibrium agricultural sector models specific to Egypt and Morocco were employed for policy tests. Consumer and producer surplus from agricultural based commodities is maximized subject to various resources, technical, and policy constraints. Positive Mathematical Programming (PMP) was used to calibrate the model. Water pricing policy, water complementary input factor tax policy, and output tax policy are tested using these two agricultural sector models. Results suggest that effective policy depends on the social, economic, and environmental contexts of specific regions. For countries like Egypt where most agricultural land is irrigated, taxes on Nitrogen (N) fertilizer and energy and output tax on water-intensive and low profit crop production may be more effective than others. For the Moroccan case, taxation on crop inputs and outputs not only affect water use in the public irrigation sector, but also private irrigation sector and rain-fed as a whole. Water pricing and output tax policies are better suited and effective than water complementary input factor taxation. Findings from Morocco might be generalized to other countries with similar irrigation characteristics and diversity in irrigated (public and private) and rain-fed land. The results for both countries demonstrate that some of the strategic irrigation policies can work towards directing cropping decisions to less water intensive crops and also generating revenues for governments in situations where governments choose not to price water.     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

不同管距时玉米渗灌效果的试验研究

在运城市夹马口灌区和红旗灌区进行了1996,1997两个年度的玉米渗灌试验,研究了不同毛管间距条件下渗灌对其产量及水分生产率等的影响。结果表明,玉米渗灌毛管间距采用0.8~1.0 m较为适宜。毛管间距愈大,产量愈低;渗灌较地面灌平均减产7.23%,较旱地平均增产30.8%;玉米生长期内总耗水量地面灌最大,渗灌次之,旱地最小。渗灌可明显提高玉米水分生产率,渗灌处理水分生产率平均为1.65 kg/m3,是地面灌的1.2倍,是旱地的1.33倍;两年度渗灌较地面灌平均节水44.4%。     

Rational Pricing of Water as an Instrument of Improving Water Use Efficiency in the Agricultural Sector: A Case Study in Gujarat,India

The agricultural sector in India accounts for over 85% of the total water used for various purposes in the country. However, the efficiency of water use in agriculture is very low, approximately 40% for surface irrigation and 60% for groundwater irrigation. Part of the reason for the low efficiency is the highly subsidized price of irrigation water that encourages the excessive application of water to crops. This paper is based on a case study conducted in the command area of a public irrigation canal in the state of Gujarat, India. It attempts to explore the role of the rational pricing of canal irrigation water in motivating farmers to use water judiciously and thereby enhance the water use efficiency in irrigated agriculture. The paper contends that farmers are sensitive to an increase in irrigation water charges, but unless the administered price is increased to the level that would prevail in a free market, it will not have its intended effect on irrigators.     

井灌类型区农业高效用水模式及产业化示范

农业高效用水管理示范工程是国家科技部在“九五”期间批准立项的重大科技产业工程项目。井灌类型区农业是我国重要的灌溉农业类型区一，提高井灌区的灌溉水利用率和单方水的生产效率，对节约用水，提高农业生产水平具有重要的意义。河北省三河市通过提高井灌区水的利用率，创建和发展了相关产业，使该项目成为农业高效用水科技产业示范工程。     

再生水农业灌溉的研究

介绍了北京市农业灌溉用水现状及污水处理的发展.结合国内外的利用情况及研究成果,证明二级处理水完全可以用于农业灌溉.经过样本分析,得出二级处理水用于农业灌溉基本可以忽略重金属的影响,研究重点应集中在养分和盐分含量的增多所引起的生态效应,并根据水质分析结果,建立再生水农业灌溉生态效应指标.     

节水灌溉工程技术在迎门山灌区中的应用

迎门山灌区因地制宜,采用多种节水灌溉工程措施,解决了灌区水资源紧缺问题,为灌溉农业的发展创造了条件,使灌区的农业发展有了保障,是灌区节水灌溉应该提倡和推广的。