共查询到20条相似文献，搜索用时 15 毫秒
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Most activities that support economic growth in the São Francisco River Basin (Brazil) need water. Allocation of the water resources to each competing use needs quantification in order to develop an integrated water management plan. Irrigation agriculture is the largest water consuming activity in the basin. It has produced large economic and social advancements in the region and has potential for further development. The local development agency in the São Francisco River has projected an increase of more than 500,000 ha in irrigation developments distributed within the basin.Water requirements of the projected irrigation expansions and their effects on river flow were quantified. A semi-distributed model was constructed to simulate the water balance in 16 watersheds within the basin. The watersheds were hydrologically characterized by the average precipitation, atmospheric demand and runoff as well as their variability. Water requirements for increased irrigated agriculture were calculated using an agronomic mass balance. A Monte Carlo procedure generated the variability of irrigation requirements and resulting decreased river flows from the multidimensional probability distribution of the hydrologic variables of each watershed.Irrigation requirements were found to be more variable during the wet season because of weather variability. In contrast to what might be expected, in drier years, irrigation requirements were often larger during the wet season than in the dry season because the cropped area is largest in the wet months and variability of precipitation is greater. Increased irrigation shifted downward the distribution of river flows but not enough to affect other strategic water uses such as hydropower. Further irrigation expansion may be limited by wet season flows. 相似文献
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Irrigation delivers major benefits in food security and human development. Irrigation also leads to waterlogging and salinity which threaten the sustainability of irrigated agriculture and pose major socioeconomic and environmental risks. The issue can be addressed by limiting net recharge to groundwater such that the water and salt keep natural equilibria. Often the information on net recharge within catchments is unavailable, particularly at lower spatial scales such as the farm or paddock; this offers little guidance for on-farm land and water management decisions—basic decisions that ultimately impact regional net recharge and waterlogging and salinity dynamics. This paper develops a cross disciplinary framework based on the concept of net recharge for setting paddock scale targets and to link these to the regional targets and community's goals for sustainable irrigation management. A management model, cast in a dynamic programming format to integrate a detailed hydrological model with an economic model was applied to estimate the productivity, profitability and sustainability of irrigated agriculture in a region of the Murray Darling Basin in Australia. SWAGMAN® Farm model was used to determine paddock scale net recharge. This interactive model enables an individual farmer to choose a profit optimizing crop mix while lowering net recharge; this in turn leads to a win-win outcome for all farmers. The net recharge metric can be used for the conversion of diffuse source groundwater recharge to a point source recharge at paddock scale, enabling the definition of private property rights to a common pool problem and assigning individual responsibilities for its management—a vexing issue and a new concept for the commons literature. Net recharge shows significant spatial and temporal variation which warrants a targeted/zonal approach to address the issue. Regional and targeted strategies and actions to address the issue are identified. Apart from its applied and action research orientation, the development of paddock scale net recharge metric is perhaps the most significant conceptual contribution of this research which can lead to shared management of groundwater aquifers. 相似文献
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Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance 总被引：1，自引：0，他引：1
The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured performances to farmers’ irrigation practices, and these practices to the underlying logic of farmers who operate these systems. This approach was applied to 22 farms in Morocco. Four sets of variables helped explain the gap between the actual irrigation performance and the performance obtained in experimental conditions: (1) farmers have agro-economic motivations or want to improve their social status, and for them, irrigation performance is at best an intermediate objective. (2) Irrigation performance is not a static value, but a rapidly evolving process, related to the (perceived) ability of farmers to change irrigation practices and renew irrigation equipment, but also to farmers’ aspirations. (3) The social network of farmers, supporting the introduction and use of drip irrigation, determines how farmers may share experience, information and know-how related to drip irrigation. (4) Today, there is no social pressure to irrigate carefully to save water; only the state explicitly links the use of drip irrigation to saving water. Making the drip user visible in research and policy studies would lead to more realistic assessments of irrigation performance and draw the attention of policy makers to the actual conditions in which drip irrigation is used, and as a consequence help incorporate ‘saving water’ as an objective for drip irrigation users. 相似文献
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应用线性规划数学模型对河南省韩董庄引黄灌区作物种植布局和引黄水及地下水联合运用进行了分析.对作物种植规划,作物灌溉增产效益,引黄工程及井灌工程运行费用,引黄供水能力等参数进行了详细分析计算,建立了灌溉水资源优化调配模型,应用计算机求解提出了灌区作物种植优化布局方案及水资源优化调配方案,并给出了各种灌溉方案条件下的灌溉效益,所得结果对灌区规划与发展具有重要参考价值. 相似文献
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基于水足迹的河套灌区多目标种植结构优化调整与评价 总被引：1，自引：0，他引：1
针对黄河水量逐年减少和农业面源污染日趋严重等因素导致内蒙古河套灌区农业用水短缺、生态环境不断恶化的问题,本文将水足迹概念（蓝水足迹、绿水足迹、灰水足迹）引入多目标优化模型和多目标决策评价模型,对灌区有限的水资源进行合理配置。以河套灌区为例,本文选取小麦、玉米、葵花、瓜类、番茄5种典型作物,从经济、社会、资源以及生态4个角度对作物的种植结构进行优化,并耦合模糊层次分析和TOPSIS法对多种优化方案（多目标优化方案、单目标优化方案、现状情景方案）进行评估优选。结果表明,在保障粮食作物产量的基本需求下,减少粮食作物小麦、玉米的种植面积,增加经济作物葵花、番茄和瓜类的种植面积,可以达到增加经济收入、保证社会公平性、提高水资源利用效率及减少粮食生产过程中给环境带来负面效应的目的。并且,评价结果表明多目标优化方案兼顾经济、社会、资源和生态多方面,优化结果优于单目标优化结果和现状情景。研究可为河套灌区及类似地区作物种植结构调整提供相应的理论依据和决策支持,助力灌区可持续发展。 相似文献
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节水灌溉效益研究进展 总被引：3，自引：2，他引：1
节水灌溉的实施是人与自然、环境交互作用的集中体现,是典型的生态-经济-社会复合系统,因此节水灌溉的效益研究应同时考虑生态、经济和社会的耦合效应.回顾了国内外节水灌溉在节水、经济、生态及灌排工程效益等方面的研究进展,在此基础上分析了目前存在的主要问题,并提出节水灌溉效益的研究应从可持续的观点,也就是要从生态、社会、经济方面量化资源利用的"可持续性"水平出发.今后应加强节水灌溉条件下水文循环变化规律、农田尺度内生物群落及其环境效应、农田生态环境容量及水资源承载力等方面的研究. 相似文献
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During the recent decades, there has been an increasing effort to transfer the management of irrigation schemes from government organizations to non-governmental organizations as decentralization gained momentum and as states started to devolve some of their functions to different groups in the society. Irrigation management in Turkey was also affected by these developments. Since 1993, approximately 90% of the public irrigation schemes were turned over to the locally managed farmer organizations.This study was conducted in the Menemen Irrigation Scheme, to assess the temporal variations of agricultural, water use, environmental and financial performance indicators for the pre-transfer (1984–1994) and the post-transfer (1995–2004) periods.Results showed, after 10 years of transfer, a continued improvement in irrigation performance. The most important finding of the study was a considerable increase in output per unit of land and per unit of water after turnover. Irrigation management transfer (IMT) provided a dramatic achievement in water fee collection efficiencies and more financially self-sustaining organizations. Therefore, it can be safely concluded that the transfer process created more sustainable management for irrigation. 相似文献
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The management of water resources by orchards in the south-eastern region of Australia is an increasingly important policy
issue, especially given the low water allocations and concerns about salinity in recent years. Optimal management for economic
and environmental sustainability can be described as best management practice (BMP). A project was developed to run an extension
program, which aimed to achieve behavioural change among orchardists through the adoption of irrigation BMPs and benchmarks.
The effectiveness of the extension program was evaluated and the drivers for adoption assessed. In the first stage of the
project both BMPs and benchmarks were determined for irrigation management. A survey of 200 growers showed no relationship
between yield and irrigation system or irrigation volume suggesting that increased yields were not a key driver for adoption
of sustainable irrigation practices. Stage two of the project involved undertaking an extension program aimed to facilitate
the adoption of BMPs and benchmarks and incorporated a suite of activities to meet the learning needs of a diversity of participants
(40 growers). The program was effective in establishing behavioural change for many of the growers involved; however, it was
resource intensive requiring significant one-on-one input. Stage three aimed to analyse the key drivers for adoption of sustainable
irrigation practices for the whole of the stone and pome fruit industry in south-eastern Australia using market research.
The study determined that water use efficiency was not a key driver for adoption of sustainable irrigation practices (micro
irrigation and soil moisture monitoring) and adoption was generally not limited by lack of knowledge. Groups of growers were
identified where extension programs could be effective by focussing on specific information e.g. redevelopment of orchard.
Other groups had no need and/or ability to change unless the external operating environment was to change e.g. regulation,
access to pressurised water. The voluntary adoption of more sustainable irrigation practices will probably require extensive
resources using one-on-one methodology. The extension program should not focus on the broader social objective of improved
water use efficiency but promote other potential benefits (e.g. labour saving, redevelopment of production systems, management
flexibility) with targeted messages for specific groups. 相似文献
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石津灌区适宜田间灌水技术试验研究 总被引：2，自引：1，他引：2
为了研究石津灌区适宜的田间灌水技术，在对石津灌区现有灌水技术调查的基础上，对不同的田间灌水方法进行了田间试验，结果表明，储水灌溉既实现了高产，节水的目的，又适应灌区的运行管理，是今后灌区渠道灌溉地区田间灌水发展的重点技术之一；小畦灌和低压管道输水灌溉，灌水灵活，在井灌或井渠结合地区具有较大的发展潜力。 相似文献
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在界定节水农业综合效益概念和内涵的基础上,从经济、环境、社会三方面提出节水农业综合效益价值评估指标体系,应用基于单位化约束条件的综合集成赋权法确定指标权重,建立以货币为衡量标准的节水农业综合效益评估模式。以皂河灌区为例,对节水农业经济、环境、社会及综合效益进行估算,即估算节水农业实施后年效益流量,分析节水农业效益价值动... 相似文献
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Bruce Alistair Lankford 《Irrigation and Drainage Systems》1992,6(2):113-128
The use of measured water in controlling flows for the irrigation of sugarcane was found to be vital for the rehabilitation and management of surface irrigation on a 5000 ha sugarcane project. Methods of water delivery, measurement and control at Inyoni Yami Swaziland Irrigation Scheme (IYSIS) are described. Improvements to the irrigation, using existing methods of water measurement, were carried out over a period of four years. The lessons gained in this programme of improvements confirmed the benefits of using modulus gates which allow a constant, measured, discharge of water. 相似文献
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The achievement of sustainable irrigation in arid regions requires greater attention to waterlogging, salinization, and degradation of ground and surface waters, which are among the problems that continue to threaten productivity and degrade environmental quality. We consider sustainability to be achieved when irrigation and drainage are conducted on-farm, and within irrigation districts, in a manner that does not degrade the quality of land, water, and other natural resources, either on-farm or throughout an irrigated region. Sustainability may also be described as maintaining the productive resources required for irrigation, so that future generations may have the same opportunity to use those resources as we do. Given the increasing importance of irrigated land for food production, the time has come when it is vital to intercept, reuse, and isolate drainage waters within the regions in which they are generated. Adoption of this strategy can be enhanced by policies that require farmers, and irrigation districts, to consider the off-farm impacts of irrigation and drainage. Such policies include linking water rights with salt rights to require the monitoring and management of both irrigation water and the salt loads in drainage waters. We review the knowledge gained since the early 1970s regarding the economic and agronomic aspects of irrigation and drainage, with a focus on drainage water reduction and sequential reuse of drainage water on salt-tolerant crops. Economic incentives that motivate farm-level and district-level improvements in water management are also reviewed. We conclude that adequate knowledge exists for implementing strategies that focus on water use and salt disposal within irrigated regions, and we recommend policies that will motivate improvements in productivity and enhance the likelihood of achieving sustainability. 相似文献
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《Agricultural Water Management》2005,71(3):181-209
Australia is the driest inhabited continent on earth, and pressure on its water resources is already high and increasing. Environmental, social, and economic drivers are forcing horticultural industries in Australia to reassess their use of freshwater resources. Reclaimed water is potentially a major resource for the horticultural industry. In general, however, there has been some apprehension towards using reclaimed water for irrigation, owing primarily to uncertainties related to agricultural sustainability and human health. Here, we consider the current standing of the Australian horticultural industry in terms of its preparedness to use reclaimed water for irrigation. We address issues related to policy, economics, market access, pragmatic directives (such as state and federal guidelines), environmental impact, agronomic sustainability, and public health. From these appraisals, we have attempted to summarise the major impediments to the use of reclaimed water by the Australian horticultural industry. These are: insufficient knowledge of impacts on market access; commitment to provide continuity of quality and supply to markets; implications of substitution of alternative water sources on security of supply; insufficient knowledge of food safety issues; inadequate understanding of consumer perceptions; and uncertainty about pricing of reclaimed water. 相似文献
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长期再生水灌溉后土壤孔隙分布的多重分形特征 总被引：1，自引：0，他引：1
土壤结构是表征土壤质量的重要指标之一.为了定量表征长期再生水灌溉后土壤孔隙分布的非均匀性,以不同年限再生水灌溉后的土壤为研究对象,采用KYKY-2800B型扫描电子显微镜获取土壤数字图像,利用数字图像处理技术测定了土壤的孔隙分布特征,运用多重分形谱参数描述了土壤孔隙分布的非均质性,探讨了土壤孔隙分布多重分形曲线对称性的意义.结果表明:多重分形谱可以定量描述土壤孔隙分布的非均质性,土壤孔隙分布的多重分形奇异谱函数α-f(α)表现为非对称连续性分布,奇异谱宽度Δα表征了土壤孔隙分布的非均质特征,大兴区北野厂灌区农田土壤孔隙分布的多重分形谱宽度Δα普遍大于石景山衙门口灌区土壤,即具有30 a再生水灌溉历史的土壤其孔隙分布的非均匀性较50 a再生水灌溉历史的土壤孔隙分布的非均匀性大,且北野厂灌区土壤小孔隙的数目小于石景山衙门口灌区土壤小孔隙数目.多重分形参数可以作为定量表征土壤孔隙分布非均匀性的重要指标. 相似文献
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F. Martí n de Santa Olalla Ma as A. Brasa Ramos C. Fabeiro Cort s D. Fern ndez Gonz lez H. L pez C rcoles 《Agricultural Water Management》1999,40(2-3):195-205
The great expansion of irrigated lands using groundwater has often caused the exploitation of aquifer reserves beyond their recharge capacity. The development of management tools which can harmonize resource exploitation with reserve sustainability is the objective of an interesting experience being accomplished in the aquifer 08.29 in Mancha Oriental, Spain. This paper offers a summary of this ongoing project (GESMO), pointing out the specific role of the Irrigation Advisory Service. The general objective of the project is to create an integrated and integral management system of the aquifer as well as to prepare appropriate techniques for its adequate exploitation. Integral management means that both supply and demand management are considered, including the socio-economic and environmental perspectives. The concept of integrated management implies that the process must involve the majority of economic and social agents affected.
Management is founded on a Decision Support System (DSS) which takes into consideration different possible options. The DSS must contemplate the impacts on the environment, mainly the aquifer reserve losses and the increase of nitrates concentration in groundwater. The project directly affects more than 5000 agricultural users, irrigating about 100 000 ha with the aquifer water resources, as well as the whole population living in this region. Results of this project, including irrigation technologies developed may be useful for other areas in the Mediterranean Basin where similar cases occur. 相似文献
