干旱区微咸水灌溉的水-土环境效应预测研究

本文运用MODFLOW及SWAP模型对微咸水灌溉的水-土环境效应进行了预测.模型参数用2004年的观测资料进行率定,并用2002年的资料对模型的可靠性进行了检验.结果显示,淋洗灌溉定额条件下,不同作物的土壤盐分积累及作物相对减产率分别比正常灌溉定额条件下有所降低;微成水灌溉后土壤盐分的积累随着时间的推移呈递减趋势,大约在10年后盐分达到进出平衡状态,平衡时土壤的含盐量(0.126%)仍属于轻度盐渍土;抽取地下微咸水灌溉后,淋洗灌溉定额条件地下水位的下降幅度及含水层盐分的增加量都比正常灌溉定额条件下有所降低.采用微咸水灌溉,淋洗灌溉比正常灌溉对环境有利.     

Determining Minor Head Losses in Drip Irrigation Laterals. I: Methodology

Minor head losses at emitter insertions along drip laterals were predicted by a derivation of Bélanger’s theorem and analyzed by the classic formula that includes a friction coefficient K multiplied by a kinetic energy term. A relationship was established for K as a function of some emitter geometric characteristics. These take into account the flow expansion behind the reduction of the cross-sectional area of the pipe due to obstruction by the emitter. Flow constrictions at emitter insertions were estimated by analogy with contraction produced by water jets discharging through orifices. An experimental procedure was also developed to determine minor losses in situ, in the laboratory or in the field. An approach is suggested to calculate either K or the emitter equivalent length le as a function of lateral head losses, inlet head, and flow rate. Internal diameter and length of lateral, emitter spacing, emitter discharge equation, and water viscosity must be known. Approximate analytical relations to study flow in laterals were developed. They may be used to design and evaluate drip irrigation units. Analytical and experimental procedures are validated in the companion paper by Juana et al.     

GIS支持下的江西省农田节水灌溉系统研究

以GIS技术支持下的江西省农田节水灌溉系统为研究对象,阐述了系统研究的主要内容、方法和技术框架,并对GIS技术在节水灌溉中应用的特点及优势进行了分析。     

观光农业园区节水灌溉技术的应用设计

阐述了观光农业是旅游消费市场的一种新型农业生产经营形态和新兴农业艺术。并简介了观光农业园区中的几种节水灌溉技术及采用节水灌溉后产生的增产增收和节水效益。     

景电一期灌区节水扩灌措施

对景电一期灌区的概况进行了介绍,分析了节水扩灌的必要性,提出了具体的节水措施,包括畦田灌溉、沟灌、地膜覆盖灌水、衬砌防渗节水、调整农作物的种植比例等,从而推广和应用先进的节水经验.     

Infiltration Variability in Furrow Irrigation

In this paper, the contribution of different sources of variability to irrigation water depth variability was quantified using a combination of variance techniques. This method was applied using field measurements from irrigation events performed on a loamy soil with a low-infiltration rate. Infiltration variability was estimated with blocked furrow infiltrometers. The assumptions made for the application of the combination of variance techniques proved to be valid. The major variability source turned out to be the soil intake characteristics, whose variance accounted for 45–71% of the variance in infiltrated depth under first irrigation conditions. Opportunity time and wetted perimeter were less variable in subsequent irrigations and the soil intake characteristics variability accounted for a percentage of total variance beyond 76%, being at times beyond 95%. The combination of variance techniques can be used to complement standard evaluation methods in order to take into account the influence of different variability sources.     

基于灰色聚类法的水利枢纽灌区PPP 项目风险评价研究

基于水利枢纽灌区 PPP 项目的一般特点及其特殊性,提出不同责任主体的 6 个风险一级指标、25 个风险二级指标的风险评价体系,通过 AHP 法确定各级风险指标权重值,运用灰色聚类法中的三角白化权函数的评估方法,将分散的风险评价信息处理成不同灰类度的评价量,从而得出项目的综合风险等级。结合 B 灌区二期工程项目进行应用分析,为我国水利枢纽灌区 PPP 项目规避风险、降低损失提供切实可行的理论指导依据。     

3#航煤膜片评级质量问题的解决办法

临氢脱色装置长期加工含硫油的腐蚀和原料带进系统的部分硫化铁微粒造成管线中残留有大量硫化铁,以及临氢脱色装置采用炉后混氢工艺引起3#航煤产品膜片评级波动,为了保障分公司2010年完成加工500万吨原油的战略任务,荆门分公司采取了频繁瞬时调量冲洗系统和活性炭吸附等措施解决了杂质微粒对航煤质量的影响。     

帕德里克·布朗克:欧洲“垂直花园”设计的发明者

本文通过对欧洲"垂直花园"设计发明者帕德里克·布朗克的生平、设计作品及设计思想源泉进行梳理和研究,深入阐述由布朗克设计的垂直花园系统的技术工艺原理及其对植物群落生境设计的思想,让人们进一步了解其在景观创作领域中的独特视角及艺术个性。     

人工湿地法治理沈抚灌渠污水的研究

采用小型人工湿地试验装置处理沈抚灌渠污水,对COD和氨氮的去除情况进行连续试验,结果证明,潜流人工湿地法可保证沈抚灌渠污水处理后完全达到COD、氨氮的设定排放标准。