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1.
This study analyzes the effects of irrigation modernization on water conservation, using the Riegos del Alto Aragón (RAA) irrigation project (NE Spain, 123354 ha) as a case study. A conceptual approach, based on water accounting and water productivity, has been used. Traditional surface irrigation systems and modern sprinkler systems currently occupy 73% and 27% of the irrigated area, respectively. Virtually all the irrigated area is devoted to field crops. Nowadays, farmers are investing on irrigation modernization by switching from surface to sprinkler irrigation because of the lack of labour and the reduction of net incomes as a consequence of reduction in European subsidies, among other factors. At the RAA project, modern sprinkler systems present higher crop yields and more intense cropping patterns than traditional surface irrigation systems. Crop evapotranspiration and non-beneficial evapotranspiration (mainly wind drift and evaporation loses, WDEL) per unit area are higher in sprinkler irrigated than in surface irrigated areas. Our results indicate that irrigation modernization will increase water depletion and water use. Farmers will achieve higher productivity and better working conditions. Likewise, the expected decreases in RAA irrigation return flows will lead to improvements in the quality of the receiving water bodies. However, water productivity computed over water depletion will not vary with irrigation modernization due to the typical linear relationship between yield and evapotranspiration and to the effect of WDEL on the regional water balance. Future variations in crop and energy prices might change the conclusions on economic productivity. 相似文献
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王凤娇 《国际沙棘研究与开发》2016,(4):32-34
灌区是农业发展的骨干,灌区耕地成为灌区内农村居民的衣食之源,其在我国农业产业化以及农村经济发展领域,一直具有不可或缺的功用,尤其是在改善区域内生态环境、水土保持等层面,地位极为重要.本文对月亮泡东灌区节水改造技术加以探究,在阐述灌区改造意义的基础上,重点介绍这一时期月亮泡东灌区节水改造形式,提出一种新型发展方向,即引入现代高新技术、绿色环保、高效低耗、环境友好型的灌区改造发展路径,包括灌区渠道的防渗节水设计、区域内管道输水灌溉设计,以及喷灌技术的应用等. 相似文献
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Globally, about 10 Mha of agricultural land is lost annually due to salinisation, of which about 1.5 Mha is in irrigated areas. While some climate and management aspects are common to semi-arid regions, the detailed mechanisms and options to secure ecological sustainability and economic viability may vary considerably from case to case. This paper applies a whole of system-water balance to compare irrigation in three semi-arid regions suffering from similar sustainability issues: Rechna Doab (RD), Pakistan; the Liuyuankou irrigation system (LIS), China; and Murrumbidgee irrigation area (MIA), Australia. Soil salinity, lack of adequate water resources and groundwater management are major issues in these areas. The MIA and LIS irrigation systems also suffer from soil salinity and low water-use efficiency issues. These similarities occur in spite of very different climatic and underlying hydrogeological conditions. The key data used to compare these different regions are climate and soils, available water resources and their use, as well as components of the water balance. In addition, the history of water resource development in these areas is examined to understand how salinity problems emerge in semi-arid regions and the consequences for production. Based on the efficiency parameters and the definitions of sustainability, approaches are explored to solve common environmental problems while maintaining economic viability and environmental sustainability for irrigation systems. 相似文献
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Cablegation is a simple system for automating surface irrigation in small- and medium-sized fields using a gated pipe. In
this work, a Programmable Logic Control, PLC, was used to develop an adaptive cablegation system capable of establishing the
infiltration equation in real time and then adjusting the irrigation times to the infiltration rate and field geometry. A
controlling program was developed for the on-field determination of the infiltration equation, simulation of advance in each
furrow, and the optimization and management of the irrigation event. The equipment was tested in three experimental stations,
including a Luvissol field organized in contour terraces with furrows of various lengths. The results demonstrate the capability
of the system to adapt the application times to the different furrow lengths and the gradual decrease in the soil infiltration
and to recommend an application depth that optimizes the Application Efficiency. Various improvements were made to this solar-powered
cablegation, resulting in a reliable surface irrigation system capable of unsupervised operation. 相似文献
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The growing necessity to develop more productive agriculture has encouraged the expansion of new irrigated lands. However, water use in agriculture may affect the natural regimes of water systems. This study aims to analyze, for the first time, water use and its dynamics during the creation of a newly irrigated land. Water use was studied through the development of water balances and subsequent application of quality indices for irrigation in two unirrigated years (2004–2005) and three years of gradual implementation of irrigation (2006, 2007 and 2008) in the Lerma basin (752 ha, Spain). Increases in evapotranspiration, drainage and water content in the aquifer were verified during the gradual transformation into irrigated land. Water balances closed adequately, giving consistency to the results and enabling the application of quality indices for irrigation. Irrigation quality analysis showed a use of available water resources equal to 84%. However, the estimated irrigation efficiency presented lower values, mainly due to irrigation drainage (15%) and combined losses by both evaporation and wind drift of sprinkler irrigation systems (13%). The results indicate that the use of water in the Lerma basin is at the same management level of other modern irrigation systems in the Ebro basin, although there is still margin for improvement in irrigation management, such as reducing the irrigation drainage fraction and the evaporation and wind drift losses of sprinkler irrigation systems. 相似文献
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美国灌溉现状分析 总被引：1，自引：0，他引：1
以１９９７年的美国灌溉统计资料为基础，结合近２０多年的数据，本文详细分析了美国的农田灌溉在近２０多年的发展状况，并从地理位置、气候类型和灌溉规模等不同角度全面分析了美国各种灌溉方法的构成、灌溉所用动力类型和灌溉农田上的作物结构。结果显示，近２０多年来，美国总灌溉面积中喷灌所占比例在不断增加，而地面灌溉比例则不断降低。１９９７的资料显示，在目前美国的灌溉面积中，喷灌是以中心支轴式系统为主，微灌以地表滴灌为主，而地面灌中则有３种类型的系统使用的较多。在灌溉农田的作物结构上，干旱地区的饲草类作物种植比例明显高于其它地区，而湿润地区的粮食作物、瓜果蔬类作物和棉花的比例较高。这种比例关系随分析的角度不同而有所变化 相似文献
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Growers who irrigate need to answer three questions throughout the growing season — (i) when should each field be irrigated;
(ii) how much water should be applied; and (iii) which field should be irrigated first. An heuristic solution procedure has
been developed to produce realistic irrigation schedules, within a practical time, for growers using hosereel-raingun irrigators.
The financial implications of the irrigation schedules are analysed over a short term period (typically 7 days). The constraints
are limited availability of equipment, labour and/or water. Use of the model is illustrated with a common situation faced
by a U.K. grower. 相似文献
10.
Irrigation performance assessments are required for hydrological planning and as a first step to improve water management. The objective of this work was to assess seasonal on-farm irrigation performance in the Ebro basin of Spain (0.8 million ha of irrigated land). The study was designed to address the differences between crops and irrigation systems using irrigation district data. Information was only available in districts located in large irrigation projects, accounting for 58% of the irrigated area in the basin. A total of 1617 records of plot water application (covering 10,475 ha) were obtained in the basin. Average net irrigation requirements (IRn) ranged from 2683 m3 ha−1 in regulated deficit irrigation (RDI) vineyards to 9517 m3 ha−1 in rice. Average irrigation water application ranged from 1491 m3 ha−1 in vineyards to 11,404 m3 ha−1 in rice. The annual relative irrigation supply index (ARIS) showed an overall average of 1.08. Variability in ARIS was large, with an overall standard deviation of 0.40. Crop ARIS ranged between 0.46 and 1.30. Regarding irrigation systems, surface, solid-set sprinkler and drip irrigated plots presented average ARIS values of 1.41, 1.16 and 0.65, respectively. Technical and economic water productivities were determined for the main crops and irrigation systems in the Aragón region. Rice and sunflower showed the lowest productivities. Under the local technological and economic constraints, farmers use water cautiously and obtain reasonable (yet very variable) productivities. 相似文献
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On-farm measurements and observations of water flow, water costs and irrigation labour inputs at the individual parcel level
were made in case studies of smallholder irrigation systems in sub-Saharan Africa and south-eastern Arabia. The systems, in
which the water source supplied either single or multiple users, were analysed to address the fundamental issues of labour
allocation for on-farm water management as this has important consequences for the success of such systems. Results show that
the costs associated with accessing water influenced labour input, because when they were low the farmers tended to increase
the irrigation rate and reduce the amount of time they spent distributing the water within their parcels. Conversely when
water costs were high, lower flow rates and more time spent in water distribution were observed, and this resulted in more
uniform irrigation and higher irrigation efficiency. Also, opportunities and demands for farmers to use their labour for activities
other than irrigation can lead them to modify operational or physical aspects of the system so that they can reduce the time
they spend distributing water within the parcels, particularly when the water is relatively cheap. Awareness and better understanding
of how farmers may allocate their labour for water management will lead to more effective planning, design and management
of smallholder irrigation systems. 相似文献
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Deficit irrigation has been suggested as a way to increase system benefits, at the cost of individual benefits, by decreasing the crop water allocation and increasing the total irrigated land. Deterministic methods are common for determining optimal irrigation schedules with deficit irrigation because considering the inherent uncertainty in crop water demands while including the lower and upper bounds on soil moisture availability is a hard problem. To deal with this, a constraint state formulation for stochastic control of the weekly deficit irrigation strategy is proposed. This stochastic formulation is based on the first and second moment analysis of the stochastic soil moisture state variable, considering soil moisture as bounded between a maximum value and a minimum value. As a result, an optimal deficit irrigation scheduling is determined using this explicit stochastic model that does not require discretization of system variables. According to the results, if irrigation strategy is based on deterministic predictions, achievement of high, long-term expected relative net benefits by decreased crop water allocation and increased irrigated land may have a higher failure probability. 相似文献
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Integration of economic and hydrologic models: Exploring conjunctive irrigation water use strategies in the Volta Basin 总被引：1，自引：0，他引：1
L. Bharati C. Rodgers T. Erdenberger M. Plotnikova S. Shumilov P. Vlek N. Martin 《Agricultural Water Management》2008,95(8):925-936
We describe the development, calibration and preliminary application of a dynamically coupled economic–hydrologic simulation–optimization model ensemble for evaluating the conjunctive use of surface and groundwater in small reservoir-based irrigation systems characteristic of the Volta Basin, Africa. We focus on a representative small reservoir-irrigation system located in the Antakwidi catchment in Ghana. The model ensemble consists of the physical hydrology model WaSiM-ETH and an economic optimization model written in GAMS. Results include optimal water storage and allocation regimes for irrigated production, given conjunctive surface water and groundwater systems. The goal of our research, conducted within the GLOWA Volta project, is to develop a decision support system for improving the management of land and water resources in the face of potential environmental change in the Volta Basin. 相似文献
14.
The environmental benefits of water table management (WTM), as a method to reduce nitrate pollution, are well known. However,
there are few published studies on the effects of WTM on water use efficiency (WUE). This paper highlights the agronomic interest
of WTM for increasing WUE of irrigated grain corn production. A field study was conducted in 2001 and 2002 at a large scale
WTM research facility in Québec, Canada. The region experienced periods of drought during the two growing seasons. This study
shows that, by keeping the water table at 0.80 m below the soil surface, there were on average 35% increases in grain corn
yields, compared to conventional free drainage. The WUEs obtained with WTM (5.1 kg m−3 in 2001 and 7.1 kg m−3 in 2002) indicate that the method is generally more water efficient than conventional sprinkler and furrow irrigation. The
WUE of WTM also compares well with that of water conservation methods such as alternate furrow irrigation and deficit sprinkler
irrigation. Moreover, WTM requires low inputs in terms of equipment, energy, and labour, because it makes use of existing
subsurface drainage systems, which are widespread in Eastern Canada due to the region's soils and climate, and because of
its design, which does not necessitate high-pressure pumps and allows for automated management. Hence, WTM appears to be an
interesting alternative to conventional irrigation methods due to its combined environmental and agronomical benefits. 相似文献
15.
《Agricultural Water Management》2005,75(2):137-151
The approval of the National Irrigation Plan (NIP) in Spain in 2001 accelerated the improvement and modernisation of the irrigated areas. The first step towards the implementation of performance of the actions envisaged in the plan is to analyse water-use in traditional irrigation. Moreover, the social impacts of irrigation on rural areas must be evaluated, and the common irrigation practices must be determined. This paper presents the results of a study conducted in the Lemos Valley irrigation district (NW of Spain). Irrigation evaluations were conducted in nine trial sites, representing the existing soil types. A sample of irrigation users were interviewed to gather information about water-use, land tenure and irrigation socioeconomics. This irrigation district is characterised by low water-use efficiency, significant losses in the distribution network, fragmented land ownership and a poor use of the available infrastructure. Yet, water availability and an important distribution network render the modernisation of this traditional irrigated land a challenging task that must be faced. 相似文献
16.
Prospects of micro-irrigation in India 总被引：2，自引：0，他引：2
R. K. Sivanappan 《Irrigation and Drainage Systems》1994,8(1):49-58
The demand for land and water in India is continuously escalating due to increased population. The land can be used intensively on even up to 3 crops in a year for which water is needed. Therefore water management and increased production are very essential and crucial for the development.Research studies conducted in India by various institutions have indicated that water saving is about 40–80% and the yield increase is up to 100% for different crops by using micro-irrigation. The incremental benefit-drip cost ratio (BI/CD) worked out for various crops ranges from 1.35 to 13.35 excluding water saving and 2.78 to 32.32 including water saving. It has also been proved that drip irrigation, which is a type of micro-irrigation, is technically feasible and socially acceptable not only for large farms but also in small and marginal farms.Drip irrigation can be adopted to large areas irrigated from wells especially for wide spaced high value crops. This method is also suitable for hilly and undulated tracts, coastal sand terrains, and to a great extent in the water scarce areas of South and Western India. About 18 million ha are under fruit, vegetables and plantation crops and the present area under drip is only about 55,000 ha. Therefore the potential and prospects of drip irrigation is very high in the coming years. 相似文献
17.
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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我国北方地区,一般是指淮河、秦岭、白龙江以北,包括黑龙江、吉林、辽宁、内蒙古、河北、北京、天津、山西、山东、宁夏、甘肃、新疆等省、自治区、直辖市的全部以及河南、安徽、江苏、陕西、青海等省的部分。土地总面积527.29万km~2,耕地面积85870万亩,人口42899.07万人。 相似文献
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针对西北干旱区灌区生态环境脆弱、水资源短缺、复杂不确定性等问题,以石羊河流域红崖山灌区为例,耦合2型模糊集、模糊可信度约束规划和多目标规划等理论方法,构建了基于2型模糊集的多目标农业-生态水土资源优化配置模型。模型以灌溉水损失最小、生态植被灌溉水满意度最大、生态植被灌溉水费用最小和主要粮食作物经济效益最大为目标,对红崖山灌区10个决策单元的地表水、地下水和粮食作物种植面积进行优化配置。求解模型得到不同可信度水平和不确定性程度下的水土资源优化配置方案。结果表明：耦合2型模糊集的模型能够提供丰富的配置方案,水量对可信度水平的敏感性高于不确定性程度,作物种植结构对可信度水平不敏感。以不确定性程度参数为0.5、可信度水平为0.7时为例,生态植被均通过地表水灌溉,作物通过地表水、地下水联合灌溉,玉米的产量和经济效益均大于小麦。相比前人研究,本研究考虑生态植被灌溉需求,优化结果更加真实合理。本研究可为决策者提供较为符合灌区实际的配置方案,为西北干旱区灌区现代化建设提供科学指导。 相似文献