共查询到20条相似文献，搜索用时 31 毫秒
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We analyze tunnel wells (surangams), traditional water harvesting systems, which have been innovated and nurtured by farmers in the Enmakaje panchayat in the state of Kerala in South India for decades. We show how the genesis and design of the indigenous knowledge-based water harvesting systems are shaped by agro-ecological conditions. We also identify issues that affect the sustainability of tunnel wells in the changing agrarian context in this region. The significance of tunnel wells is declining, even though the smallholders, who dominate the agricultural landscape, are highly dependent on tunnel wells to meet their water requirements. Grass roots efforts are needed to revive this traditional water harvesting system. 相似文献
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PLC变频调速节能灌溉系统的设计 总被引：1，自引：0，他引：1
在分析了变频调速灌溉系统与阀门开度调节灌溉系统的节能效果之后,得出了一种新型的农业灌溉系统供水方式,即利用PLC结合变频器的方式来实现恒压变流供水。给出了变频调速灌溉系统结构图,并进行了系统软件流程设计。系统能够连续采集水泵流量,与设定的工作压力进行比较,实时改变水泵电机的工作频率调节灌溉流量。从而改变了传统农业依靠控制阀门开度及人工启停水泵电机的操作方法。经过实验证明,采用变频调速的节水灌溉系统,比传统模式节能20%~69%。对设备寿命周期的延长,节约电能和人工成本,提高灌溉可靠性方面均有极积的意义。 相似文献
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K. Brooksbank E.J. Veneklaas D.A. White J.L. Carter 《Agricultural Water Management》2011,100(1):76-83
Shallow groundwater can often develop when perennial ecosystems are replaced by annual agriculture. Returning trees to these landscapes is one option available to farmers to use more of the incident rainfall and stop the rising water table before it begins to affect production of the traditionally planted crops and pastures. This study examines the growth and water use of mallee (multi-stemmed) eucalypts in landscape positions with different water availability, integrated into an annual cropping and pasture farming system in the dryland agricultural zone of Western Australia. We found a ten-fold difference in biomass accumulation and a six-fold difference in rates of water use depending on water availability. Water use on a leaf area basis appeared to be independent of changes in water availability but transpiration efficiency in terms of grams of carbon fixed per litre of water transpired increased with increasing water availability. Thoughtful placement of trees in the landscape will minimize the area of land required to be planted to have the desired effect on the local hydrology, thus maximizing the amount of land on which the traditional annual crops and pastures can continue to be grown. 相似文献
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Hans Charles Komakech Marloes L. MulPieter van der Zaag Filbert B.R. Rwehumbiza 《Agricultural Water Management》2011,98(11):1719-1726
Although spate irrigation systems are risk-prone, they can be an important component for livelihood security in semi-arid areas. Spate uses water (flood water), which upstream users often do not require, as rainfall during these periods is more than sufficient. The use of this flood water for spate irrigation is therefore a good opportunity to convert water with a low opportunity cost to high value water. As more rivers are closing, due to socio-economic and climate changes, spate irrigation may become increasingly relevant in semi-arid areas. Spate irrigation systems pose institutional and technical challenges: collective action is challenged by complex upstream-downstream interactions between users within the system, and the high labour demands for regular reconstruction of temporary diversion weirs and intake structures. This paper describes a spate irrigation system in Makanya village, Tanzania that emerged in response to increased upstream water use. We use three of the four dimensions (hydrological, hydraulic and sociological) of spate irrigation proposed by Van Steenbergen (1997) to assess the Makanya spate irrigation system. The Makanya spate irrigation system has an organisational structure that is similar to the canal irrigation (furrow) committees located upstream, and effectively deals with the institutional demands of managing water in spate irrigation systems. Water allocation is reminiscent to the water sharing arrangements existing in the full irrigation system, which previously was in place at the site and in the high- and midlands of the Makanya catchment and therefore set this system apart from the traditional spate irrigation practice elsewhere. Technically, a major challenge is the reconstruction of the head works after each flood. Another aspect is the changes in the river bed. Flash floods carry sediments that deposit on the fields, raising the elevation of the irrigated land every year and making it increasingly difficult for the river water to enter the plots. Improving system efficiency through modernisation of the diversion and distribution structures in this case is not feasible due to the huge amounts of sediments delivered to the system each year. Instead investments in conjunctive use of groundwater could be the solution because it involves a relatively small intervention, minimises the physical disturbance of the system, and therefore is likely to respect the existing locally developed water management arrangements. 相似文献
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海水淡化作为淡水资源的开源增量技术,已成为解决全球水资源危机的重要途径。近年来,热法和膜法海水淡化技术的应用日益广泛,然而在海水淡化中仍存在着能耗大、运行成本高等突出问题,节能、高效海水淡化技术的研究和应用已受到普遍重视。综述了压缩空气储能发电技术（CAES）、大深度反渗透海水淡化技术（ROID）以及CAES和ROID集成海水淡化技术的发展现状,提出了大深度CAES和ROID集成海水淡化系统的设计方案,并对大深度CAES和ROID集成海水淡化和传统海水淡化系统的能耗进行了对比分析,淡水产量相同时,大深度CAES和ROID集成海水淡化系统的能耗仅为传统海水淡化系统的20%。 相似文献
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通过对水稻浅湿间歇灌溉适宜间歇天数的试验研究 ,得出水稻分蘖期、拔节孕穗期、抽穗开花期和成熟期的适宜间歇天数分别为 6～ 8d、2～ 4 d、3～ 6 d和 3～ 6 d,综合节水率为 1 8.2 % ,增产率为 1 0 .1 %。这一成果对水稻浅湿间歇灌溉节水技术的推广应用具有重要价值。 相似文献
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W.R. Norman W.H. Shayya A.S. Al-Ghafri I.R. McCANN 《Irrigation and Drainage Systems》1997,12(1):35-48
This paper reports on results from a case study on water management within a traditional, falaj irrigation system in northern Oman. In the planning and design of regional irrigation development programs, generalized assumptions are frequently made as to the efficiency of traditional surface irrigation systems. Although qualitative accounts abound, very little quantitative research has been conducted on on-farm water management within falaj systems. Daily irrigation applications and crop water use was monitored during an 11-month period among 6 farm holdings at Falaj Hageer in Wilayat Al-Awabi. Contrary to the frequent assumptions that all surface irrigation systems incur unnecessarily high water losses, on-farm ratios of crop water demand to irrigation supply were found to be relatively high. Based on actual crop water use, irrigation demand/supply ratios among monitored farms varied from 0.60 to 0.98, with a mean of 0.79. Examination of the soil moisture budget indicates that during most irrigations of wheat (cultivated in the low evapotranspiration months of October–March) sufficient water is applied for the shallow root zone to attain field capacity. With the exception of temporary periods of high falaj delivery flows or periods of rainfall, field capacity is usually not attained during irrigations within the more extensive root zones of date palm farms. The data presented in this paper should provide a better understanding of water use performance by farmers within traditional falaj systems. Moreover, these data should also serve to facilitate more effective development planning for irrigation water conservation programs in the region. 相似文献
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首先对农村供水管网管段流量设计计算的传统方法进行了分析，指出其适用条件和局限性。在此基础上，提出了加权人畜用水当量法。该方法结合农村供水的实际情况，既考虑了人畜分布的不均，又考虑了用水量的差别，并且计算公式简单，设计易与实际相一致，是一种计算农村供水管网管段设计流量的有效方法。 相似文献
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针对长期以来传统水利工程点多、面广、线长,通讯不便,管理手段落后、粗放,工程效益差,灌溉效率低,"人治"痕迹深,安全管理不合理、不到位,事故频发的问题,充分利用智能感知技术、3S技术、云计算云存储技术、物联网技术以及WebGIS等先进信息技术,实现由传统水利向数字水利过渡,最终彻底向智慧水利转型,建立数字唐徕信息化管理系统。系统包括数字地图决策指挥平台、综合数据分析查询平台、智能灌渠专家辅助系统、掌上唐徕移动信息终端、数字唐徕渠业务管理支撑平台、自动化采集测控平台的"数字唐徕渠"的六个"一"的功能架构。是一套真正满足灌区管理需求的呈现数字化、控制智能化、决策科学化、管理协同化的灌区生产指挥管理平台,为全渠管理部门提供了科学的决策依据。 相似文献
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针对传统灌溉施肥方式无法切实满足作物生长需求和水肥资源浪费严重的问题,设计一种基于PSO和BP神经网络优化PID模型的水肥控制系统。系统通过结合作物种植环境水肥浓度信息,利用PSO和BP神经网络算法优化PID控制参数,以解决水肥施灌过程中系统的非线性、时变性和滞后性等问题。综合MATLAB/simulink仿真试验结果可知,利用PSO和BP神经网络优化的PID控制模型较传统PID控制模型系统响应速度提高9.33%,调节时间缩短72.24%,超调量仅为PID控制的11.78%,优化效果较好。系统试验结果表明,施灌过程中系统控制稳定,在一定程度上达到水肥浓度精准控制的效果,具有实际应用价值。 相似文献
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为研究解决池塘养殖污染、水资源浪费和水产品安全等问题,针对传统淡水鱼类池塘养殖特点,设计了一种生态工程化循环水池塘养殖系统,系统由生态沟渠、生态塘、潜流湿地和养殖池塘组成,面积比为1︰5︰3︰30,系统中池塘呈串联结构排列,池塘对角方向建设有水层交换过水设施,系统利用1级动力提升形成循环水流。在池塘养殖密度0.20～0.82 kg/m3和系统水体日交换量10%～15%的情况下,水质检测结果表明,池塘养殖水体中的铵氮、亚硝态氮、硝态氮、总氮、总磷、化学需氧量（COD）等水质指标分别低于1.89、0.20、1 相似文献
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Since the early-1960's, when modern rice production technologies became available, more than 90% of the total irrigation water developed in south and southeast Asia is used for rice culture. But currently rice culture is highly inefficient in water use. As fresh water availability for agriculuture is becoming increasingly scarce, greater efficiency of water use in rice culture is deemed essential. Past experience indicates that effective implementation of water-efficient irrigation methods in rice farms within public sector irrigation systems is restricted by the difficulty of controlling water deliveries and distribution, and establishing a water charge system based on the actual amount of water used by farmers. Clearly, a rice production method that is inherently less water-requiring, or more water-efficient, would have an advantage over the traditional method in this respect. Recent studies conducted in the Philippines indicate that wet-seeded rice culture is superior to the traditional transplanted rice culture in terms of water efficiency. Other advantages of wet-seeded rice culture include its greater drought tolerance, less labor requirement for crop establishment and weed control, and higher returns from rice farming. This paper presents a comparative study of wet-seeded and transplanted rice cultures focusing on these aspects. 相似文献
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基于两线解码技术的水肥一体化云灌溉系统研究 总被引：2，自引：0，他引：2
针对传统设施农业水肥利用效率低、信息采集量少、数据挖掘利用弱等问题,设计了基于两线解码技术和云计算的设施农业水肥一体化智能云灌溉系统,包括智能云灌溉控制系统、全自动水肥一体机和高效节水灌溉系统3部分。该系统通过两线解码技术,利用各种传感器实时采集各单个设施农业作物生长环境的参数信息,并将各类采集数据及时传输和存储于数据管理云平台,根据设施农业种植区采取的环境信息和作物的需水需肥规律,利用云集群的计算和分析能力,科学确定设施农业中不同环境条件下作物生长的水肥需求和灌溉施肥制度,实现水肥一体化的智能控制。通过2个设施农业种植基地的应用实例表明,相比传统灌溉方式,水分和肥料的利用率分别提高了25%~40%和15%~35%,并且大幅度减少了劳动时间和劳动力。 相似文献
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【目的】研究平原河网区不同尺度下水稻不同灌溉模式的节水和减污效应。【方法】于2017年在浙江平湖灌溉试验站选取水稻常规灌溉、节水灌溉、蓄雨节水灌溉3种模式在试验小区和田块2种尺度下开展对比试验,记录田间水量平衡过程并检测排水和渗漏水样中的TN、TP、NH_4^+-N、NO_3^--N的质量浓度变化。【结果】无论试验小区还是田块尺度,蓄雨节水灌溉的节水效果最好,较常规灌溉和节水灌溉减少了43.4%～87.7%的灌溉量,同时减污效果也最明显,TN排水负荷减少了22%～90%。不同尺度对比中,试验小区的田间管理水平更高,产量略高于田块尺度;小区田间水分控制更精确,灌排次数和水量较田块更多,蒸发蒸腾量和渗漏量则略少于田块。在减污效果上,单位面积下同种灌溉模式的田块的排水污染物负荷比试验小区低37%～57%,渗漏负荷比试验小区高4%～61%,由于排水污染物负荷要远大于渗漏污染物负荷,在总的污染物负荷上田块要小于小区。【结论】本试验中蓄雨节水灌溉模式取得了较好的节水减污效果,但是要注意蓄雨时间和高度,长时间的淹水可能会对水稻产量造成不利影响。 相似文献
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