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Water shortage is a serious problem in most countries in theMiddle East. Irrigation water consumes about three-fourths of theavailable fresh water resources in Jordam and many othercountries in the region. This article presents a practical approachto manage and optimize the irrigation water use in the region.The ultimate objective is to minimize the outside water and tomanage the irrigation water use under geographic,socio-economic, and demographic constraints. This approach usesthe added value (net revenue) of one cubic meter of waterconcept in evaluating different irrigation water use management.This concept has been demonstrated, based on a case study in theJordan Valley.This case study shows that water scarcity can be incorporated inirrigation water management by proper choice of crops andfarming patters. The objective function is to maximize the netrevenue from the agricultural production process subjected tolimitation on water and other production and marketing factors.Results of analysis showed that a net water saving of about9%occurred if the objective function is to minimize water useunder the same level of profitability. This example shall beuseful for water and agricultural planners. Sometimes virtualwater is widely exported in form of crops that consumes largeamounts of water without full economic consideration to theadded value of water. In some cases, food imports may be afeasible option in water-poor countries instead of water import. 相似文献
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Malin Falkenmark 《国际水资源开发杂志》2001,17(4):539-554
The world is moving towards a dangerous situation of societal instability due to our failing ability to manage the life support system on the human-dominated planet. Contributing to this problem are inherited and biased ways of thinking, originating from the 17th century and based on fragmentation and sectorization. A fundamental shift in thinking is therefore needed urgently, to better bridge the partial realities addressed up until now. Awareness has to be built up around the need for societal adaptation to hydroclimatic constraints, and strong enough institutions must be developed, capable of supporting unpopular decisions. A proper conceptualization is badly needed of the life support system in a science of 'environmentology', in which water is acknowledged as the bloodstream of the biosphere. Both land/water linkages and water/ecosystem linkages will have to be properly entered into an integrated and catchment-based land/water/ecosystem approach. The goal has to meet both societal needs and environmental sustainability conditions. Attention will have to be paid to all water, both liquid blue water, supporting humanity and aquatic ecosystems, and vapour-form green water, supporting terrestrial ecosystems, agriculture and forestry. The economic resource will have to be seen as the precipitation over the basin. Both water-dependent and water-impacting activities and ecosystems in the basin have to be analysed. Joint attention will have to be paid to environmental security, water security and food security. Methods for compromise building between incompatible water-related interests and ecosystems will have to be developed. Societal acceptance will depend on awareness campaigns - make water everybody's business - and has to be secured by participation. A new ethics of hydrosolidarity will have to be developed between those living upstream and those living downstream in a river basin. 相似文献
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Applying Minimum Night Flow to Estimate Water Loss Using Statistical Modeling: A Case Study in Kinta Valley, Malaysia 总被引:1,自引:1,他引:0
Jaber M. A. Alkasseh Mohd Nordin Adlan Ismail Abustan Hamidi Abdul Aziz Abu Bakar Mohamad Hanif 《Water Resources Management》2013,27(5):1439-1455
Minimum night flow (MNF) is a common method used to evaluate water loss in a water network. In 2010, the average percentage of non-revenue water for the state of Perak in Malaysia was 29.4 %, a figure which resulted in major financial, supply, and pressure losses, as well as excessive energy consumption. In this study, a statistical analysis of the water distribution network and a modeling of MNF were carried out to estimate water loss in Kinta Valley, Perak. Flow and pressure for 361 zones were monitored for 24 h using PrimeWorks software (version: 1.5.57.0). Thirty study zones were randomly selected from 361 zones. MNF was screened within the time band of 1:00 am to 5:00 am. A total of 20 factors for physical, hydraulic, and operational variables were selected and correlated with MNF (L/s). Multiple linear regression was used as a statistical technique to determine factors that contributed to MNF (L/s). Consequently, pipe length (m) and pipe age (year) were the main contributors to MNF (L/s). The statistical model was finalized with R-Sq 0.706 and then improved to R-Sq 0.779. Results of the study revealed that 84.9 % of MNF frequencies for the 30 study areas were found at the time band 2:15 am to 4:15 am; therefore, the mean MNF for each zone in 2010 was determined to be between 1:00 am and 5:00 am. Statistical analyses showed that number of connections, total length of pipe, weighted mean of age of pipe, and type of pipe (100 mm asbestos cement) contributed to MNF. Moreover, approximately 97.5 % of registered repairs were conducted on pipes with small diameters of less than or equal to 50 mm. Pipes within this size range are usually used as service pipes and service connections. 相似文献
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根据目前普遍存在的政府投资项目审计中发现的工程变更问题,以余姚市为例,阐述了工程变更的各方面原因,并通过分析其原因,提出了有效减少工程变更的若干对策措施与建议. 相似文献
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分析了东莞市现状供水水源构成,总结供水系统中存在的主要问题包括过渡依赖东江水、供水能力不足、供水保证率低等,提出要保护并利用蓄水工程,改造供水管网,优化供水系统,强化供水管理等解决东莞市供水问题的对策及思路。 相似文献
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Cecilia Tortajada 《国际水资源开发杂志》2000,16(1):73-87
Mexico is well ahead of many developed and developing countries in many ways, especially in terms of the numbers of water projects constructed, successful transfer of irrigation districts and development of informal markets for groundwater. However, the deterioration of the natural resources of the country, water resources being one of them, due to improper management is not improving the lifestyle of the vast majority of the population in any significant way. Accordingly, extensive modifications in the planning and management processes, including consideration of environmental and social factors and stakeholder participation, are urgently necessary for the water sector. This paper includes an analysis of the environmental impact statements of water projects in Mexico which are under the responsibility of the national water authority. It concludes that the unsatisfactory quality of the EIS of water projects in Mexico represents a serious limitation for developing any post-project evaluation or impact management. The institutional arrangements necessary for implementing the proposed measures are not defined, and the costs of implementing any recommendation are not properly budgeted for in the cost tables. Finally, not only should the reports be critically analysed, but also the whole process of their preparation and approval should be objectively and critically reviewed. This analysis should indicate clearly the shortcomings of the process, and then outline what steps could be taken to overcome them in order to ensure the sustainability of water projects in Mexico. The emphasis should be on producing a streamlined and implementable process . 相似文献
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农民饮用水工程是一项民心工程,针对莲都区饮用水工程建设情况及建后管理工作存在的问题,介绍了当地政府关于强化饮用水建后管理采取的有效措施,并对解决饮用水建后管理提出了自己的思路。 相似文献
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城市水环境承载力灰色关联分析等级评价研究 总被引:1,自引:0,他引:1
从水环境承载力概念出发,通过建立城市水环境承载力评价指标体系、分级评价标准,引入灰色关联理论,构建了灰色关联分析等级评价模型,定量化地评价一定阶段内区域水环境与经济社会协调发展的程度,并通过实例对方法的可行性进行检验。结果表明:2001~2005年区域水环境承载力评价值均处于Ⅲ级,水环境与经济社会发展处于非协调发展状态;在现有经济技术条件下,水资源短缺和生态环境用水率低是影响该市水环境与经济社会协调发展的主要因素,必须努力开源节流,加大环保投入及水环境治理工作的力度。提出的模型具有计算简便,所得结果清晰、明确等特点,对于多因素、多指标的城市水环境承载力评价具有很好的适用性。 相似文献
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截流式污水处理厂采用沿河截流办法收集合流污水,合流污水包括由供水导致的“市政污水”及由流域径流导致的“旱季河水”。当“旱季河水”在水量中所占比例较大时,需要分析“旱季河水”在不同水平年的全年逐日过程,从而计算清楚截入污水厂的合流污水流量及浓度、截流管超负荷时溢出的流量及浓度、河流的流量及浓度,这对于正确确定污水处理厂的规模、选择合适的工艺与参数、评估对河流水质的保护程度,都十分重要。对截流式横岭污水厂,展开上述问题的研究,为同类工程建设提供参考。 相似文献
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水环境安全及其指标体系研究-以北京市为例 总被引:15,自引:0,他引:15
针对人类对水的需求的严峻形势,在环境安全研究逐渐成为科研热点的背景下探讨并系统提出了水环境安全这一新概念;在可持续发展指标体系研究的基础上,运用“压力(Pressure)-状态(Situation)-响应(Response)”(PSR)概念模型建立了水环境安全评价指标体系;应用综合指数法进行了水环境安全的综合评价;最后以北京市为例做了实证研究,并对其水环境安全保障提出了一些建议。 相似文献
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福州市水资源及水环境问题探讨 总被引:1,自引:0,他引:1
介绍了福州市沿海区域水资源和水环境概况。针对该市市区地处闽江下游 ,南、北港横穿城区的特点 ,指出闽江福州段存在的主要水环境问题是 :市区内河与北港中下游污染严重 ;北港河床下切 ,南港枯水期断流 ,影响水厂取水和引水工程建设。指出解决福州市水环境问题宜走工程建设和管理相结合的道路 ,并讨论了具体的方案和措施 相似文献
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Forecasting Urban Water Demand Via Wavelet-Denoising and Neural Network Models. Case Study: City of Syracuse, Italy 总被引:3,自引:3,他引:0
Forecasting urban water demand can be of use in the management of water utilities. For example, activities such as water-budgeting, operation and maintenance of pumps, wells, reservoirs, and mains require quantitative estimations of water resources at specified future dates. In this study, we tackle the problem of forecasting urban water demand by means of back-propagation artificial neural networks (ANNs) coupled with wavelet-denoising. In addition, non-coupled ANN and Linear Multiple Regression were used as comparison models. We considered the case of the municipality of Syracuse, Italy; for this purpose, we used a 7?year-long time series of water demand without additional predictors. Six forecasting horizons were considered, from 1 to 6?months ahead. The main objective was to implement a forecasting model that may be readily used for municipal water budgeting. An additional objective was to explore the impact of wavelet-denoising on ANN generalization. For this purpose, we measured the impact of five different wavelet filter-banks (namely, Haar and Daubechies of type db2, db3, db4, and db5) on a single neural network. Empirical results show that neural networks coupled with Haar and Daubechies?? filter-banks of type db2 and db3 outperformed all of the following: non-coupled ANN, Multiple Linear Regression and ANN models coupled with Daubechies filters of type db4 and db5. The results of this study suggest that reduced variance in the training-set (by means of denoising) may improve forecasting accuracy; on the other hand, an oversimplification of the input-matrix may deteriorate forecasting accuracy and induce network instability. 相似文献
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This paper presents a case study for the allocation pattern of available water resources within and among competing sectors that would achieve the highest economic return from water use. For this purpose, an optimization model using linear programming was developed. Considering constraints on greenhouse area, crop production and seasonal per capita water requirements along with the area-specific conditions and potential growth, the optimal water allocation pattern between the prevailing and future consuming sectors was determined. The results indicated that, at present, water resources are misallocated as well as under-priced; current municipal and agricultural water prices represent 61% and 69%, respectively, of the actual water cost. With the development of tourism in the area, the agricultural sector is expected to diminish as more profitable uses of water evolve. 相似文献
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Water Quality Assessment of the Santiago River and Attenuation Capacity of Pollutants Downstream Guadalajara City,Mexico
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The Santiago River in Mexico has been seriously polluted because of rapid urbanization and industrialization activities, lacking of appropriate planning and contamination monitoring policies. This research characterized the river water quality and recognizes some overall pollution sources, using two different information references: a dataset of 5 years from the Jalisco State Water Commission and a 14‐year dataset from the National Water Commission. Two zones have been identified as the main sources of pollution (hotspots), where the major events of urban and industrial wastewater discharges occur: (i) the urban fringe of Guadalajara city, with special emphasis in its southern area (nearby the so‐called El Ahogado stream) and (ii) downstream of Guadalajara City. Nevertheless, we have recognized some areas along the Santiago River where significant reduction of pollutants concentration takes place, possibly due to dilution by the inflow of tributaries and to the rainfall increasing. In addition, it is likely that hydropower dams are positively influencing the retention of pollutants along the river. In the lower zone, the water concentrations of O2 are consistently above acceptable levels (up to 5 mg L?1), and the majority of the pollution indicators parameters are below the maximum permissible values, despite the high pollution in Guadalajara area. This paper attempts to offer a methodological approach for a more accurate assessment of the river water quality and may assist in interpreting the sampling results derived from the regular monitoring, conducted by the state water authorities, while emphasizing the natural attenuation capacity of the Santiago River. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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XIE Hong-zhong 《水利水电快报》2006,27(24):11-21
1 IntroductionAnewgeneration of water wheel could be a modern solu-tion to the energy crisis and air pollution in the UK throughsmall-scale hydropower generation,eventhoughit hasfallen outof fashion over the past 50 years .Before the Industrial Revolu-tio… 相似文献
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Strategic Water Resources Planning: A Case Study of Bangladesh 总被引:1,自引:0,他引:1
Many agrarian countries have heavily invested in large-scale water projects to promote their agricultural development. There have been, however, few attempts to devise strategic water resources planning accounting for the macroeconomic linkages ofagriculture. This article presents such a strategic water resourcesplanning framework for Bangladesh. First, a dynamic costminimization model is solved to compute the optimal investmentneeded in various water projects such that an agricultural growthtarget can be met. Next, the minimum cost solution is againderived accounting for the macroeconomic linkages of agriculture,which, under different macroeconomic scenarios, results innoticeably different policy implications for optimal waterplanning. These results suggest that the traditional sectoralapproaches of planning water investment projects are generallyinconsistent with the broader macroeconomic reality of Bangladesh. 相似文献
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Gordleton磨坊小水电改造工程水能开发和环境影响评估 总被引:1,自引:0,他引:1
水能和环境影响的评估,对于判别英格兰新福里斯特区埃文河Gordleton磨坊重新安装一台改良水车或一台水轮机或一台阿基米德式螺旋水轮机的可行性和经济性是至关重要的。基于一个典型水文年份年平均径流量0.41m3/s且合理利用水资源的方案,Gordleton磨坊改造后的年电力输出为26000~30000kW·h。实地调查并记录了当前的环境变量,包括土地利用、植被、基层、水质、鱼类、无脊椎动物和噪音等。其中,鱼类洄游,特别是受法律保护的二龄鲑,将会受到工程影响,需要安装网格为1cm2的护鱼筛网并提供鱼道。噪音和振动也是主要的环境影响,采用隔音材料可以降低其负面作用。推荐采用0.15m3/s的旱季生态系统的补偿流量。 相似文献