促进长江流域灌溉发展 保障流域粮食安全

长江流域是我国重要农业生产区,为稳定和提高流域的粮食生产能力,保证未来流域内的粮食安全,流域灌溉规划至关重要。对照长江流域两次灌溉规划产生的历史背景和规划目标,分析了流域的灌溉现状及存在问题。从稳定和提高流域粮食生产出发,以国家粮食发展纲要为目标,依据流域内不同地区的实际情况,提出了发展流域灌溉的思路和目标,以及完成规划目标应采取的相应措施。规划目标实现后,将有效保障长江流域的粮食安全,并促进经济社会的和谐发展。     

话说农业灌溉

发展节水灌溉，才能保证我国的粮食安全，实现农业的可持续发展。     

灌区灌溉管理存在的问题与对策

灌区灌溉管理工作是一项系统工程,做好灌溉管理工作对于保障灌区粮食安全,保障国家粮食安全,增强农业综合生产能力,提高农民收入,改善生态环境,进一步夯实大中型灌区为主的农业基础设施,提高灌溉用水效率与效益,促进灌区现代化和农业现代化建设,促进农民增收和区域经济发展意义重大。     

加强农业节水的意义及发展方向

我国农业用水量大,占全国总用水量的62%左右,同时传统的农业灌溉方式浪费严重,与我国水资源短缺的局面极不协调。加强农业节水对于提高我国水资源的利用效率,确保我国水资源与农业生产的可持续发展,增加我国粮食安全都具有十分重大的战略意义。2011年6月召开的中央水利工作会议强调,在未来10年我国将大力加强农田水利建设,其中加强农业节水将是农田水利建设的重要内容,大中型灌区的渠系改造、喷微灌节水灌溉技术的推广应用等将成为未来我国水利投资的重点。     

加快灌区建设与发展的对策探讨

我国的人口问题和耕地、气候、水资源等自然条件，决定了水利是农业生产的根本保障，农业必须走灌溉农业的发展道路。因此，加强灌区建设、改造和利用是保障国家粮食安全的重要途径。     

建昌县高效节水灌溉工程建设与运行管理分析

高效节水灌溉项目的实施既适应了新阶段农业发展需要，又进一步提升农业发展的总体水平，解决了建昌县农业灌溉新方法。它既推动农业节水灌溉技术的普及与深入发展，又改善了农业生产条件，确保了粮食综合生产能力的提高，为国家粮食安全提供坚实支撑。文章对建昌县高效节水灌溉工程建设与建后运行管理的必要性和重要性进行了分析，并使工程能够发挥出其最大的能力，发挥其应有的效益，运行发挥得更长久一些是非常必要的也是非常重要的。     

甘肃省临泽县水资源约束与农业生产承载力评价

水资源总量短缺、利用效率偏低等问题是我国粮食安全面临的严峻挑战,保障粮食安全的水资源问题长期存在。进入新发展阶段,如何有效应对水资源约束对我国粮食安全的威胁,已成为当前亟待解决的重大难题。以甘肃省临泽县为例,梳理水资源开发利用现状和农业生产情况,通过评价农业生产灌溉承载力,综合分析区域水资源对农业生产的影响,并从盘活水资源存量、严控水资源总量、去除水资源增量、提高水资源质量等四个方面提出保障粮食安全的基本举措,为科学高效利用水资源、切实保障粮食安全提供重要参考。     

创新驱动节水灌溉高质量发展 夯实农业强国建设基础

论述了我国节水灌溉发展现状和存在问题，从建设农业强国、夯实粮食安全基础、推进国家现代化和生态文明建设等方面分析节水灌溉面临的新形势，阐明了新时期节水灌溉高质量发展目标和任务，提出健全政策制度、强化两手发力、增强管理与服务、加强技术创新、催化效益驱动等对策措施。     

21世纪全国及九大流域片粮食需求预测分析

中国人多地少，粮食安全保障很大程度依赖于灌溉。水资源短缺的现实要求科学合理地制定未来灌溉面积发展、农业用水及国家食物安全政策，而对未来我国粮食需求的准确预测分析是其基础和前提。因此，本文利用开发的CAPSIM-PODIUM模型为工具，预测分析了2010和2020年全国及九大流域片包括大米、小麦和玉米等粮食需求量。研究表明，人口增加和收入提高后间接引起饲料粮需求增加是未来粮食需求增长的主要原因。预计2020年全国粮食(贸易粮)需求将达到5．07亿t，比2000年提高25％。人均口粮消费还会缓慢下降。玉米等饲料粮需求将快速增长。     

节水灌溉与粮食安全

当前,保障粮食安全已成为日益关注的重大政治、经济和社会问题。人口增长,耕地减少,水资源紧缺,对安徽省未来的粮食安全产生直接影响。本文在分析安徽省粮食生产及其主要影响因素的基础上,初步分析了节水灌溉对保证粮食安全和农业可持续发展的关键作用。     

Policy Options to Improve Water Allocation Efficiency: Analysis on Egypt and Morocco

Abstract

Because of political risk, economic feasibility, and cultural concerns, it has been a great challenge for economists to provide palatable remedies to governments to promote water allocation efficiency. Considering the limitation of water pricing to irrigation water, this research addresses questions of which strategic policy alternatives to water pricing might improve irrigation water allocation efficiency. An empirical framework is provided to compare irrigation policies for allocating scarce water to agricultural production in Egypt and Morocco. Partial-equilibrium agricultural sector models specific to Egypt and Morocco were employed for policy tests. Consumer and producer surplus from agricultural based commodities is maximized subject to various resources, technical, and policy constraints. Positive Mathematical Programming (PMP) was used to calibrate the model. Water pricing policy, water complementary input factor tax policy, and output tax policy are tested using these two agricultural sector models. Results suggest that effective policy depends on the social, economic, and environmental contexts of specific regions. For countries like Egypt where most agricultural land is irrigated, taxes on Nitrogen (N) fertilizer and energy and output tax on water-intensive and low profit crop production may be more effective than others. For the Moroccan case, taxation on crop inputs and outputs not only affect water use in the public irrigation sector, but also private irrigation sector and rain-fed as a whole. Water pricing and output tax policies are better suited and effective than water complementary input factor taxation. Findings from Morocco might be generalized to other countries with similar irrigation characteristics and diversity in irrigated (public and private) and rain-fed land. The results for both countries demonstrate that some of the strategic irrigation policies can work towards directing cropping decisions to less water intensive crops and also generating revenues for governments in situations where governments choose not to price water.     

Optimization of Irrigation Scheduling Using Soil Water Balance and Genetic Algorithms

In arid and semi-arid countries, the use of irrigation is essential to ensure agricultural production. Irrigation water use is expected to increase in the near future due to several factors such as the growing demand of food and biofuel under a probable climate change scenario. For this reason, the improvement of irrigation water use efficiency has been one of the main drivers of the upgrading process of irrigation systems in countries like Spain, where irrigation water use is around 70 % of its total water use. Pressurized networks have replaced the obsolete open-channel distribution systems and on farm irrigation systems have been also upgraded incorporating more efficient water emitters like drippers or sprinklers. Although pressurized networks have significant energy requirements, increasing operational costs. In these circumstances farmers may be unable to afford such expense if their production is devoted to low-value crops. Thus, in this work, a new approach of sustainable management of pressurized irrigation networks has been developed using multiobjective genetic algorithms. The model establishes the optimal sectoring operation during the irrigation season that maximize farmer’s profit and minimize energy cost at the pumping station whilst satisfying water demand of crops at hydrant level taking into account the soil water balance at farm scale. This methodology has been applied to a real irrigation network in Southern Spain. The results show that it is possible to reduce energy cost and improve water use efficiency simultaneously by a comprehensive irrigation management leading, in the studied case, to energy cost savings close to 15 % without significant reduction of crop yield.     

确定农田灌溉定额的三种优化目标的比较

本文针对灌水量与作物产量间所经常表现出的二次抛物线的情况，就分别以追求产量、生产效率和生产弹性系数的最大值为目标的农田灌溉定额的判定结果进行了比较。研究表明，使灌水生产效率达到最大的灌溉定额只有当作物在雨养条件下无产量形成时才存在，而使生产弹性系数达到最大的灌溉定额只有当作物在雨养条件下有产量形成时才存在。考虑经济因素后的结果与此类似，区别在于此时不仅与雨养条件下能否形成产量有关，还与除灌水以外的单位面积固定费用、单位产量及单位灌水量的综合价格有关。文章同时认为，对于线性的产量与灌水量关系而论，在灌水量的取值区间内，三种优化目标的解是不存在的。     

Domestic Use of Irrigation Water: Health Hazard or Opportunity?

In an environment of growing scarcity and competition for water, there is increasing pressure on the irrigation sector to make irrigation for crop production more efficient and to transfer water to the urban, industrial and environmental sectors. However, irrigation water is extensively used for non-agricultural purposes, including domestic purposes, and an exclusive focus on water efficiency in agriculture could actually reduce the availability of domestic water within irrigated areas. It is argued, based on available literature, that this would have important health implications because in many developing countries the availability of water, rather than the quality of water, is of crucial importance to health. Two case studies are presented from Sri Lanka and Pakistan where people make use of irrigation water for a range of domestic activities. Water resource policies have to take these uses into account to avoid negative health implications for poor disadvantaged segments of the population. Barriers to optimizing benefits of linking the irrigation water supply to domestic needs seem to be institutional and psychological rather than medical, technical or economic.     

基于作物耗水定额控制的灌溉管理模型

海河流域水资源供需矛盾突出,其中农业灌溉所占用水量和耗水量比例最大,而其水分利用效率相对偏低,因此节水潜力较大,为合理调控区域灌溉用水,本文将田间试验观测为基础的灌溉节水理论和方法与遥感数据反演区域耗水(ET)的点面优势相结合,提出了基于作物耗水定额管理的农业灌溉管理模型,通过控制区域上的作物耗水量分布,促进区域灌溉水资源的合理调配和利用,实现资源性节水。模型主要功能包括遥感反演数据统计分析、区域耗水目标分解、作物ET定额分配、种植结构调整、节水潜力分析以及净灌溉需水量估算。可实现从区域综合耗水控制目标向主要作物ET定额的分解,并转化为灌溉用水管理中可控制的灌溉定额,通过逐年设置主要作物的ET控制定额和种植结构情景方案,分析区域的节水潜力,消除奢侈耗水,实现不同水文年和耗水控制阶段目标下的灌溉定额管理,为区域灌溉水管理提供技术支持。     

Evaluation of Crop Models for Simulating and Optimizing Deficit Irrigation Systems in Arid and Semi-arid Countries Under Climate Variability

The variability of fresh water availability in arid and semi-arid countries poses a serious challenge to farmers to cope with when depending on irrigation for crop growing. This has shifted the focus onto improving irrigation management and water productivity (WP) through controlled deficit irrigation (DI). DI can be conceived as a strategy to deal with these challenges but more knowledge on risks and chances of this strategy is urgently needed. The availability of simulation models that can reliably predict crop yield under the influence of soil, atmosphere, irrigation, and agricultural management practices is a prerequisite for deriving reliable and effective deficit irrigation strategies. In this context, this article discusses the performance of the crop models CropWat, PILOTE, Daisy, and APSIM when being part of a stochastic simulation-based approach to improve WP by focusing primarily on the impact of climate variability. The stochastic framework consists of: (i) a weather generator for simulating regional impacts of climate variability; (ii) a tailor-made evolutionary optimization algorithm for optimal irrigation scheduling with limited water supply; and (iii) the above mentioned models for simulating water transport and crop growth in a sound manner. The results present stochastic crop water production functions (SCWPFs) that can be used as basic tools for assessing the impact on the risk for the potential yield due to water stress and climate variability. Example simulations from India, Malawi, France and Oman are presented and the suitability of these crop models to be employed in a framework for optimizing WP is evaluated.     

现代灌溉新技术旱作膜袋灌

通过对华北平原地区旱作大田作物田间灌溉方式的调查研究,发现传统的地面灌水方法存在着蒸发量大、深层渗漏多,水分利用效率低,田间灌水均匀度差等问题。为了提高旱作大田的水分利用效率,提出一种新的灌溉新技术——旱作膜袋灌,实现适时适量精细控制灌溉。通过试验研究,膜袋灌能够较好地提高大田作物的田间水分利用效率,避免沟灌、畦灌等传统地面灌水方法存在的棵间蒸发和深层渗漏,同时也能够解决滴灌、微润灌、喷灌等灌水方法易堵塞、系统复杂、田间工程量大和经济成本高等问题,对现代的高效节水农业具有重要的现实意义。     

黄土旱区作物-水分模型

本文依据田间试验数据，采用Jensen模式，研究了黄土旱区冬小麦、春玉米这两种优势作物的 水分模型。研究结果表明，小麦在播种～返青期缺水敏感指数(λ)最大，对缺水最为敏感；拔节～抽穗期次之，然后是抽穗～灌浆期，而灌浆～成熟期和返青～拔节期的敏感性最小。总耗水量在320～420mm之间，灌水量为260～300mm左右、且分布在冬前和拔节～抽穗期是节水高产高效的灌水模式。玉米拔节-抽穗期和抽穗-灌浆期对缺水最敏感，拔节前和灌浆-成熟期敏感性小。说明拔节后到抽穗期补水对产量作用最大，其次为抽穗-灌浆期。这为黄土旱区制定灌溉制度提供了重要理论依据。     

基于供求关系和生产函数的灌区水量使用权交易模型

随着市场在资源配置中的作用日益重要,水权交易对优化水资源配置、提高用水效率、促进节水势在必行,现已成为我国最严格水资源管理制度试点建设的重要内容之一。本文运用水资源系统分析与经济学理论,建立了基于供求关系和生产函数的灌区水量使用权交易模型,该模型以交易双方各自收益最大化为目标,由C-D生产函数和供求关系确定水资源价值,以纳什均衡价格和供需水量为约束确定交易水量和交易收益。经湖北省高关水库灌区与应城市水量使用交易应用研究,结果表明:高关水库灌区随着节水深入,2013年现状、2020、2030规划水平年在50%平水年交易水量最大,分别为3 744.78万m3、4 743.51万m3、5 829.13万m3;75%、85%干旱年交易水量分别减少到1 225.28万m3~4 180.79万m3,213.65万m3~1 570.17万m3;90%特旱年则不具备交易条件。通过双方交易,可使应城市2013、2020、2030水平年50%平水年缺水情况明显缓解,75%和85%干旱年缺水率降低;还可提高高关水库灌区净收益201.73万元~7 0541.97万元,应城市净收益88.37万元~131 669.00万元。但要根本解决应城市干旱缺水问题,需要建立灌区节水量交易收益补偿投入机制,调动节水积极性,充分挖掘当地节水潜力。这对建立健全我国水权交易机制和最严格的水资源管理制度,提高水资源利用效益与效率,指导节水型社会建设,保障城乡供水安全,具有重要意义。     

宁夏半干旱区玉米滴灌灌溉制度试验研究

为了促进宁夏半干旱区节水灌溉技术的推广应用,本文针对宁夏扬黄灌区规模推广玉米大田滴灌缺乏相关滴灌灌溉制度的突出问题,采用大田小区对比试验与示范区技术应用监测相结合的方法,开展了玉米裸地滴灌灌溉制度试验研究。在综合分析玉米生育期灌溉定额、土壤含水率变化、耗水量、作物产量、水分生产效率的基础上,研究提出了玉米生育期滴灌11~12次、灌水定额300~450 m3/hm~2,灌溉定额4 200~4 425 m3/hm~2的滴灌灌溉制度。研究结果表明:玉米大田滴灌目标产量15 000 kg/hm~2,水分生产效率达到3.0 kg/m3,玉米滴灌较大田畦灌可提高经济效益3 735元/hm~2,同时节水1 800 m3/hm~2、节水30%以上。