An evaluation of the Porac River irrigation system     

James A. Weller 《Irrigation and Drainage Systems》1991,5(1):1-17

An irrigation water management research programme was implemented by Hydraulics Research in collaboration with the National Irrigation Administration of the Philippines on the Porac Area of Porac Gumain Rivers Irrigation System. The objectives of the study are to monitor the response of the main canal network to changes in water availability and assess its capability to deliver crop water requirements to sub-areas jointly managed by National Irrigation Administration staff and existing Irrigator Associations. This paper presents an analysis of the response of the main system to the varying irrigation demands, and assesses the conjunctive use of groundwater with surface water and the potential of computer models to assist management with the preparation of the annual irrigation schedules.  相似文献   

Division of irrigation water in The Fayoum,Egypt     

W. Wolters  Nadi Selim Ghobrial  M. G. Bos 《Irrigation and Drainage Systems》1987,1(2):159-172

The division of irrigation water in The Fayoum, Egypt, has been measured. Factors influencing this division are discussed: the hydraulic conditions at structures and canals, the operation regime of gates, lack of reliable gauge data for system operation, shortage of labour, and the water level in Lake Qarun. A deviation from uniform supply has been found for the entire Fayoum, but also along a lateral and sub-lateral. The reasons for this are discussed and suggestions for possible technical improvements of The Fayoum system are given.Abbreviations FWSBM Fayoum Water and Salt Balance Model Project - MSL Mean Sea Level at Alexandria - FID Fayoum Irrigation Department - mcm million cubic metres  相似文献   

长时序海量土地利用时空数据统计优化方法     

郜允兵  张翼鹏  高秉博  潘瑜春  张晓东 《农业机械学报》2015,46(S1):290-296

针对任意查询区域年度现状地类面积统计困难、长时序变更流量分析计算耗时等问题,提出基于时空变化图模型的统计优化方法。运用图的连通性原理,对查询统计区域内和边界处的要素实体进行分类,实现了时序快照统计优化算法,解决了任意查询区域时点现状统计困难的问题,提高了时序快照统计的效率。运用多商品流原理进行时空网络图约化性判定,实现了变更流量统计优化算法,减少了要素空间叠置分析次数,解决了长时序土地利用变化变更流量统计耗时问题,提高了统计的效率。最后,以2009—2012年琼海市土地利用数据为例,进一步验证优化算法的有效性和可行性。  相似文献   

Effects of arrangement of surge-rootirrigation emitters on growth,yield andwater use efficiency of apple trees     

LI Zhongjie  FEI Liangjun  HAO Kun  LIU Teng  CHEN Nanshu  ZHANG Quanju  HUANG Deliang 《排灌机械工程学报》2020,38(7):713-719

Six-year old apple trees were selected for field experiment. The objective of this study was to obtain the reasonable arrangement of surge-root irrigation emitters in apple orchards. There were three factors: the buried depth H( 25,40,55 cm),the horizontal distance L( 30,40,60 cm) between the emitters and the trunk of the experimental tree,and the number of the irrigation emitters N( 1,2,4). The effect of the arrangement of surge-root irrigation emitters on the growth,yield and irrigation water use efficiency( IWUE) of apple trees were studied in Northern Shaanxi where the irrigation quota takes 60%-75% of the field water capacity. The results showed that the arrangement of emitters for surge-root irrigation had a significant effect on apple tree yield and IWUE,especially,the yield and IWUE reached 28 388. 17 kg/hm2 and 16. 83 kg/m3 in treatment T3,respectively. At the same L and N levels( T1,T2,and T3),the yield and IWUE in treatment T3 were the highest,and the yields in treatments T1 and T2 were decreased by 26.22% and 31.48%,while IWUE is reduced by14.02% and 18.12% compared with T3,respectively. At the same H and N levels( T3,T4,and T5),the yield and IWUE of apple trees were decreased with increasing L level. Especially,when L was 30 cm( T3),the yield and IWUE were the highest. The same L and H levels( T3,T6,and T7) could promote the growth of apple trees when N was 2( T3). Compared with treatment T3,it was found that the increment of new shoots was decreased by 8.07%-18.71%,and the fruit diameter was decreased by 5.41%-9.11%. Therefore,two emitters should be arranged symmetrically on both sides of an apple tree,each was buried at a 40 cm depth and 30 cm away from the trunk of the tree to effectively improve the yield and IWUE of the apple tree in mountainous areas in Northern Shaanxi.  相似文献   

滑动轴承在农业机械中的使用与维护     

张凯  郝静  李漫江 《农机化研究》2007,(11):74-76

轴承主要用来支承轴及轴上零件,并保持轴的旋转精度和减少转轴与支承之间的摩擦和磨损.为此,探讨了滑动轴承的工作原理、常见故障类型及采取的防范措施,针对故障原因对滑动轴承进行日常维护,为推动轴承在农业机械中的合理使用和维护提供参考依据.  相似文献   

秸秆覆盖对冬小麦耗水特征及水分生产率的影响   总被引：13，自引：0，他引：13  

许翠平  刘洪禄  车建明  赵立新 《灌溉排水学报》2002,21(3):24-27

2季冬小麦试验结果表明 ,秸秆覆盖具有减少土壤棵间无效蒸发的作用 ,冬小麦返青前 1 m土层贮水量在砂壤土条件下秸秆覆盖处理比无覆盖处理增加 2 %～ 2 5 .8% ,粘壤土条件下增加 2 %～ 1 4.5 %。返青前秸秆覆盖处理比无覆盖处理的日耗水量普遍小 ,返青后情况则相反。秸秆覆盖能够促进作物生长 ,与无覆盖相比 ,提高水分生产效率 4.6%～ 2 5 .2 %。  相似文献   

城市生活用水考核指标体系   总被引：1，自引：0，他引：1  

张庆华  王正山  兰孝新 《中国农村水利水电》2004,(6):37-39

提出了城市生活用水考核的指标体系。该考核体系分城市生活用水单元和城市总体生活用水两个类型，从生活用水、重复利用、排水、用水管理等4个方面对生活用水进行考核，从而全面的反映城市生活用水情况，对城市生活用水的规范化、科学化管理，促进节约用水将起到积极的作用。  相似文献   

上海市水权交易的潜力分析—从产     

张文斌  周彩丽  蒋文闻 《中国农村水利水电》2007,(9):33-35

随着城市经济的发展，农业、工业、生活和生态环境用水之间竞争加剧，运用市场机制和经济手段来合理分配水资源是目前国际社会所采取的战略举措。基于不同产业的用水效率和效益的差异分析，说明在产业间开展水权交易可优化水资源配置。现以工业化程度最高的上海为例，对上海的用水结构与产业结构进行对比分析，揭示水权交易的内在去驱动力，并提出了推动水权交易实践的政策建议。  相似文献   

Effects of planting density on the productivity and water use of tea (Camellia sinensis L.) clones: I. Measurement of water use in young tea using sap flow meters with a stem heat balance method     

Julius M. Kigalu   《Agricultural Water Management》2007,90(3):224-232

Sap flow meters based on the stem heat balance method were used to measure the mass flow rates or water use in young potted tea (Camellia sinensis L.) plants of clones AHP S15/10 and BBK35. The meters were constructed on site and installed onto the stem or branch sections of field growing plants in an experiment originally designed to study the effects of plant population density and drought on the productivity and water use of young tea clones. The objective of the study was to use the SHB method as a first attempt to use sap flow meters for determining the water use of young tea growing in the field under well watered conditions in Tanzania. The results are reported and recommendation made for further work on using the technique.  相似文献   

GIS在农业水土领域的应用与研究进展   总被引：5，自引：0，他引：5  

卢敏  张展羽 《中国农村水利水电》2004,(9):8-11

介绍了近年来国内外GIS在农业灌溉管理、精确农业和农业区划、土壤利用和土壤侵蚀方面的研究和应用情况，并对GIS在该领域的研究进行归纳和总结，此外探讨了GIS在当前农业领域应用的主要发展方向。  相似文献