不同灌溉方式下坝上高寒地区错季蔬菜种植的经济效益分析——以尚义县为例

结合坝上高寒地区的灌溉需水量大、水资源短缺严重、多种节水灌溉方式并存的实际情况,以尚义县为例,分析了该县种植的白萝卜、生菜、大白菜分别在膜下滴灌、喷灌、管灌的灌溉方式下的成本和效益,并对它们进行比较,得出该地区最具有经济效益灌溉方式--膜下滴灌.并对该灌溉方式所产生的节水、省工、增产、节肥、节地的社会经济效益加以论述.     

浅谈高效设施农业节水灌溉技术

本研究简单介绍了我国水情及设施农业发展节水灌溉的必要性,并重点介绍和探讨了设施农业吐灌、沟灌、膜下灌溉等6个目前设施农业中应用家广泛的节水灌溉技术,旨在说明设施农业发展节水灌溉的重要性.     

简讯

西部建设的重点今后 5～ 10年 ,西部地区基础设施建设的重点是 :水利方面 :内蒙古河套灌区、关中灌区、黑河流域灌区等重点灌区将实施节水工程 ;建设田间蓄水工程、抗旱保水工程、节灌补水工程、耕地培肥与监测工程等旱作节水农业示范基地 ;因地制宜推广渠道防渗、管道输水、喷灌、滴灌等实用节水技术 ;推行工业循环用水和居民生活节水 ,促进污水处理和中水回用 ;重点实施塔里木河、黑河整治工程 ,加强长江上游、黄河中上游水土流失综合治理 ;兴建岷江紫坪铺、黄河沙坡头、嫩江尼尔基、右江百色等水利工程 ;增加农业灌溉用水 ,解决农村人畜…     

浅谈水利工程灌区节水技术的改造

节水灌溉是一个针对性较强的概念,任何一项灌水技术的直接影响范围都只能是某个灌区.依据我国大型灌区的工程与管理现状,在分析节水灌溉涵义的基础上,结合某地灌区发展现状,提出了节水灌溉的技术措施以及发展节水灌溉需要研究的技术问题.     

也谈节水灌溉

节水灌溉具有公益性、社会性和综合性等特点,判断节水灌溉的标准要从灌溉水的利用效率、水分生产率、经济效益及环境影响等四个方面来衡量.选择节水灌溉方式,要遵循园地制宜、注重实效的原则,从工程基础条件、管理体制、经济调节、科技动手等方面综合考虑,采取多种措施,促进节水工作的深入开展.     

天钢游泳池水处理优化设计和节能应用

阐述了天钢游泳池水处理系统中的硅藻土过滤器的技术特点,通过对石英砂和硅藻土过滤设备过滤机理、技术性能、节水效果比较分析,并通过实地考察及使用人员调查,认为天钢游泳池采用硅藻土过滤技术先进可靠,有利于保证池水的卫生安全,节水节能,值得推广.     

节水灌溉水利设施探讨

我国是一个农业大国,引水灌溉历史悠久.近年来,由于地球生态环境恶化,植被人为破坏严重,部分地区沙化漫延,农业高耗水量作物的引进和推广,城镇人口增加,地下水超量开采等因素,缺水已成为制约我国国民经济发展的重要因素,农业灌溉用水日趋紧张.为了解决区域用水的紧张局面,党和国家提出对灌区实施渠道防渗等措施.各级水利部门也加大农业节水灌溉工程投资,积极推广先进节水灌溉技术.随着灌区更新改造、农业综合开发、世界银行贷款以及扶贫等多个项目的实施,灌区加大渠道防渗工程建设,以缓解农业灌溉用水的供需矛盾.     

华北区耗水型果树节水技术集成模式综合评价

运用熵权综合评价法对"耗水型果树减蒸降耗及种植管理节水技术集成与示范"项目形成的苹果、梨节水技术集成模式进行了评价.结果表明:梨以外围沟灌最优,局部灌溉次优,漫灌最差;苹果以局部灌溉最优,小管出流次优,漫灌最差.     

不同灌水方式对辣椒生长、生理的影响

[目的]为辣椒节水灌溉提供科学依据.[方法]通过盆栽试验分析了正常灌溉、根系分区固定灌溉与根系分区交替灌溉对辣椒生长及生理指标的影响.[结果]当灌水下限为75%θF时,分区固定灌溉的辣椒株高显著低于正常灌溉与分区交替灌溉;与正常灌溉相比,分区固定灌溉的辣椒叶宽降低明显;正常灌溉的辣椒叶绿素含量最高,分区交替灌溉次之,分区固定灌溉最低;正常灌溉的辣椒脯氨酸含量最低,分区交替灌溉居中,分区固定灌溉最高.同种灌水方法下不同灌水下限的辣椒叶绿素含量表现为75%θF>65%θF>55%θF. 当灌水下限为55%θF与65%θF时,分区交替灌溉辣椒脯氨酸含量显著高于分区固定灌溉.同种灌溉方法下辣椒叶宽随灌水下限降低显著下降.在同等灌水下限条件下,分区交替灌溉的辣椒叶宽显著大于分区固定灌溉.[结论]控制性根系分区交替灌溉是最节水高效的灌溉方式.     

高炉长寿技术——炼铁清洁生产技术

近年来高炉生产大型化,精料、高风温、高顶压、富氧、喷煤、节能、炉料分布控制技术以及高炉自动化水平方面都取得了显著的进步,现分述如下:(1)冷却水质量。软水或纯水闭路循环冷却技术,已大面积推广。它不仅避免了冷却器结垢,能长期保持冷却效率,而且节水效果显著。这项技术已     

Measuring On-Farm Irrigation Efficiency with Chloride Tracing under Deficit Irrigation

Water is a limited resource in agricultural production in arid climates. Under such conditions, high irrigation efficiency can be obtained either through implementation of efficient irrigation systems such as drip or sprinkler systems or through the age-old practice of deficit irrigation with gravity systems. The method used to increase irrigation efficiency is often dictated by economic and/or social factors. In either case, the effectiveness of water management at the farm level needs to be evaluated by measuring irrigation efficiency. The objective of this study was to evaluate the irrigation efficiencies for three crops in Southern New Mexico using the chloride technique. The chloride technique is a simple method in which the natural chloride in the irrigation water is used as a tracer to estimate the leaching fraction and the irrigation efficiency at the farm level. Soil samples were collected from various fields in 15 cm increments to a depth of 180 cm at the end of the irrigation season. The samples were analyzed for moisture and chloride content. In addition to the chloride technique, on-farm irrigation efficiencies were measured using applied water, yield, and water production functions. Water production functions and yields were used to estimate total evapotranspiration while flow measurements were used to calculate the amount of applied water. The results showed that high irrigation efficiency can be accomplished using deficit irrigation. Irrigation efficiency values ranged from 83 to 98%. Irrigation efficiencies using the chloride technique were compared with efficiencies estimated from direct flow measurements. The differences between the two methods ranged from 2 to 11.4%. The results showed that even though the chloride technique is subject to sampling errors and simplified theoretical assumptions, it can be used to estimate on-farm irrigation efficiency with considerable accuracy.     

Irrigation Offtake Sensitivity

This article is an attempt to develop an analytical framework to address sensitivity of irrigation offtakes. The perturbation of water depth and the deviation of the setting are considered for analysis. Sensitivity of delivery takes into account the impacts of the perturbations on the delivery (to the command area of the offtake). Sensitivity of conveyance assesses the effects on the conveyance discharge of the parent canal. Analytical formulations of six sensitivity indicators are provided. The concept of head loss equivalent is introduced to explicitly take into account the hydraulic behavior in the dependent canal downstream of the offtakes. Hydraulic perturbations are considered either as upstream deviations in the parent canal or downstream perturbations in the dependent canal.     

光伏灌溉系统的设计

介绍了光伏灌溉系统的相关配置方案、设计方法及主要设备参数的计算方式。光伏灌溉系统是解决缺水、缺电地区灌溉用水问题的新方法,对农业灌溉、荒漠治理有很好的利用价值。     

Operational Sensitivity of Irrigation Structures

The adjustment of structures along irrigation free-surface systems aims to achieve, or maintain, a targeted status of the canal network. The interaction between structures and reaches is an important aspect of canal control and the process of the operation itself can generate perturbations. These perturbations depend on the frequency and mode of operation as well as the sensitivity to the setting of the structures. Highly sensitive structures generate relatively large changes in their outputs for small input changes. Therefore, highly sensitive structures should be operated with more precision than others to minimize deviations between the actual and targeted states. Knowing which are the sensitive structures along a canal and how to operate them is essential for a cost-effective operational procedure. This paper presents a set of sensitivity indicators that enable the identification of sensitive structures and an assessment of their operational tolerance.     

Measuring Irrigation Well Discharges

Irrigation wells frequently discharge directly into canals. Upstream elbows, the pump head, or other pipe fittings may produce a distorted flow profile that is detrimental to the proper installation and operation of commonly available pipe meters. Before attempts to condition the flow with longer discharge piping or straightening vanes, it is desirable to know how distorted the flow profile really is. If this information can be provided, the meter technician can determine whether a correction in the meter coefficient will suffice, or if flow conditioning equipment is needed, or whether flow conditioning equipment, if already installed, is working effectively. An economical method of field evaluating the result of an installed meter in this compromised situation is described. The method uses a conveniently fashioned pitot-tube system that can be clamped to the pump discharge pipe. It is used to quickly detect the velocity at several points across the pipe diameter. Distorted profiles can be detected and measured. Pitot-tube systems have long been used in pipe flows. Most require that special taps be drilled in the outflow pipe of the well. Some use special double-tube constructions that are difficult to build using simple machine-shop procedures. This pitot impact tube, with its static pressure companion tube, can be constructed using common shop techniques and standard small pipe fittings.     

Effects of Magnetized Water and Irrigation Water Salinity on Soil Moisture Distribution in Trickle Irrigation

Magnetized water is obtained by passing water through a strong permanent magnet installed in or on a feed pipeline. This study was performed at Gorgan Agricultural and Natural Resources Research Center, Gorgan province, Iran, to investigate soil moisture distribution under trickle irrigation. Two main treatments of magnetic and nonmagnetic water and three subtreatments of irrigation water salts, including well water as a control, 200-ppm calcium carbonate, and 400-ppm calcium carbonate were used. The experiment was laid out with a complete randomized block design with three replications. Soil moisture distribution around the emitters were measured 24?h after irrigation during the 3-month irrigation period. The results showed that the mean soil moisture contents at depths of 0–20, 20–40, and 40–60?cm below the emitter for the magnetized irrigation water treatment were more than the nonmagnetized irrigation water treatment, and the differences were significant at the 5% level. The irrigation with magnetic water as compared with the nonmagnetic water increased soil moisture up to 7.5%, and this increase was significant at the 1% level. The effect of irrigation water salinity on soil moisture was significant. The highest soil moisture content was from the 400-ppm calcium carbonate subtreatment. The use of magnetized water for irrigation is recommended to save irrigation water.     

Benefits of Flexible Irrigation Water Supply

This paper develops a general introduction into the concepts of a flexible irrigation water supply in rate, frequency, and duration together with the benefits to the farmer for doing so. A flexible water supply allows the farmer the opportunity to choose an on-farm irrigation practice that best meets the needs of the desired crop, the cost and availability of labor, and other local economic or social situations. As water quality issues are more closely tied to the issues of water quantity, water use efficiency must improve. A flexible irrigation water supply can lead to improved efficiencies. Non-point-source pollution and in-stream flows also become factors in other social issues such as the care of threatened and endangered species. Flexible supplies can again help. This paper also shows, through a case study, the application of a limited rate arranged system to an irrigation district in Washington State where significant flexibility has led to efficient water use and economic and environmental benefits.     

Calibration of On-Demand Irrigation Network Models

In this study, a new procedure for calibrating on-demand irrigation network models was developed. This procedure used a new objective function called maximum data with a reasonable error (MDRE) for calibrating the network. It was compared with the two more commonly used objective functions in calibration procedures that are the simple least squares (SLS) and the maximum likelihood estimator for the heteroscedastic error case (HMLE). In order to carry out the calibration, a quasi-Newton optimization method was used having as variable the Hazen-Williams head losses coefficient (C). This procedure was applied to an on-demand irrigation network located in Tarazona de La Mancha (Albacete, Spain) where flow and pressure at hydrant level was measured. The calibration procedure using the MDRE objective function was applied considering all the pressure control points simultaneously and the obtained results were compared with the results of considering the pressure control points independently. Therefore, the effect of the location of the pressure control point was studied. Results showed that, when the proposed objective function was used, the root mean squared error (RMSE) comparing the measured and simulated data after calibration was lower than when the SLS or HMLE objective functions were used. The location of the pressure control points throughout the irrigation network could affect the results; therefore, it was more accurate to use all the control points simultaneously than independently in the calibration process.     

Analysis of Residential Irrigation Distribution Uniformity

Irrigation has become commonplace for residential homeowners desiring high quality landscapes in Florida. The goal of this project was to document irrigation system uniformity in Central Florida and to quantify distribution uniformity of residential sprinkler equipment under controlled conditions. The catch-can testing procedure used was a modified version of both the American Society of Agricultural Engineers standard and Florida Mobile Irrigation Laboratory (MIL) procedures. The modified version included a larger sample size to ensure complete sample collection over the entire irrigated area. The standard MIL procedure may overestimate the uniformity for residential systems. From the tests on residential irrigation systems, the average low quarter distribution uniformity (DUlq) value was calculated as 0.45. Rotary sprinklers resulted in significantly higher DUlq compared to fixed pattern spray heads with 0.49 compared to 0.41, respectively. From uniformity tests performed on rotor and spray heads under ideal conditions, rotor heads had more uniform distributions than the spray heads of 0.55 compared to 0.49, respectively. Spray heads had better uniformity when fixed quarter circle nozzles were used as opposed to adjustable nozzles. Both residential irrigation system and controlled tests resulted in (DUlq) at the low end of industry guidelines. Residential irrigation system uniformity can be improved by minimizing the occurrence of low pressure in the irrigation system and by ensuring proper spacing is used in design and installation.