Latent vs. Observed Variables: Analysis of Irrigation Water Efficiency Using SEM and SUR

In this paper we compare conceptualising single factor technical and allocative efficiency as indicators of a single latent variable, or as separate observed variables. In the former case, the impacts on both efficiency types are analysed by means of structural equation modeling (SEM), in the latter by seemingly unrelated regression (SUR). We compare estimation results of the two approaches based on a dataset on single factor irrigation water use efficiency obtained from a survey of 360 farmers in the Guanzhong Plain, China. The main methodological findings are that SEM allows identification of the most important dimension of irrigation water efficiency (technical efficiency) via comparison of their factor scores and reliability. Moreover, it reduces multicollinearity and attenuation bias. It thus is preferable to SUR. The SEM estimates show that perception of water scarcity is the most important positive determinant of both types of efficiency, followed by irrigation infrastructure, income and water price. Furthermore, there is a strong negative reverse effect from efficiency on perception.     

Optimisation of water procurement decisions in an irrigation district: the role of option contracts

Water supply instability is one of the main risks faced by irrigation districts and farmers. Water procurement decision optimisation is essential in order to increase supply reliability and reduce costs. Water markets, such as spot purchases or water supply option contracts, can make this decision process more flexible. We analyse the potential interest in an option contract for an irrigation district that has access to several water sources. We apply a stochastic recursive mathematical programming model to simulate the water procurement decisions of an irrigation district's board operating in a context of water supply uncertainty in south‐eastern Spain. We analyse what role different option contracts could play in securing its water supply. Results suggest that the irrigation district would be willing to accept the proposed option contract in most cases subject to realistic values of the option contract financial terms. Of nine different water sources, desalination and the option contract are the main substitutes, where the use of either depends on the contract parameters. The contract premium and optioned volume are the variables that have a greater impact on the irrigation district's decisions.     

Adoption of farm‐based irrigation water‐saving techniques in the Guanzhong Plain,China

This article analyses adoption of farm‐based irrigation water saving techniques, based on a cross‐sectional data set of 357 farmers in the Guanzhong Plain, China. Approximately 83% of the farmers use at least one farm‐based water‐saving technique. However, the traditional, inefficient techniques border and furrow irrigation are still prevalent whereas the use of advanced, more efficient techniques is still rather rare. We develop and estimate an adoption model consisting of two stages: awareness of water scarcity and intensity of adoption. We find that awareness of water scarcity and financial status enhance adoption of more advanced techniques whereas access to better community‐based irrigation infrastructure discourages it. We furthermore find both community‐based irrigation infrastructure and farm‐based irrigation water‐saving techniques have mitigating effects on production risk. From the results it follows that adoption can be stimulated via financial support and via extension aimed at enhancing awareness of water scarcity.     

Achieving environmental flows where buyback is constrained

Theory suggests that the development of common property increases national welfare, and consistent with this thinking Australia's Murray–Darling Basin (MDB) Plan uses a common property approach to recover environmental water rights in the national interest. Two water recovery instruments are used: purchasing water rights (buyback) from farmers, and saving water by subsidising irrigator adoption of technically efficient technology. A moratorium on buyback has focused environmental recovery on subsidised technically efficient technology adoption. Economists argue that national welfare is maximised via buyback and highlight the limitations of efficiency savings to recover sufficient environmental water. A risk is that water recovery targets may be reduced in future, limiting welfare gains from water reform. This article evaluates possible welfare trade‐offs surrounding environmental water recovery outcomes where arbitrary limits on buyback are imposed. Results suggest that, on average, strategies which attempt to obtain >1500 gigalitres (GL) of water from on‐farm efficiency investments will only provide sufficient resources to meet environmental objectives in very wet states of nature. We conclude that reliance on technically efficient irrigation infrastructure is less economically efficient relative to water buyback. Importantly, the transformation of MDB irrigation will significantly constrain irrigators' future capacity to adapt to climate change.     

粮食主产区妇女的农田水利管理模式偏好及参与灌溉管理意愿研究

粮食主产区担负着保障国家粮食安全的重任,农田水利是农业生产的基础。在新型城镇化背景下,妇女是农业生产的主要劳动力。粮食主产区妇女的农田水利管理模式偏好及参与灌溉管理意愿对确保粮食安全至关重要。结果表明,集体化、家庭化解决了分散、细碎农地的灌溉问题,乡村精英能降低农田水利市场化程度,男性青壮年劳动力可缓解农田水利的灌溉压力。"单打独斗"的灌溉管理模式不足以保障水田作物的季节性需求。农村教育、耕地面积、乡村精英管理有助于增进妇女参与农田灌溉管理的意愿。     

An empirical assessment of the value of irrigation water: the case study of Murrumbidgee catchment*

Evaluation of value of irrigation water is essential for supporting policy decision making relating to investments in the irrigation sector, efficient allocation of irrigation water and water pricing and for crafting policies to compare the variable impacts of water reform within and across sectors of the economy. This paper asks the question of how much an established irrigator would pay for water and at what price farmers planning to expand the area they have under irrigation would consider paying for the right to access water. An analytical framework is developed to estimate the net present value of both annual and perennial agricultural activities in the Murrumbidgee catchment. Using these estimates the total value of water used in Murrumbidgee catchment is estimated. An aggregate water supply curve is derived for the catchment from where water may be acquired from irrigators for environmental flows.     

THE DEMAND FOR IRRIGATION WATER IN AN INTENSIVE IRRIGATION AREA

Linear programming procedures offer a useful means of estimating irrigation water demand functions at the farm level. If such estimates are to be aggregated to form regional demand schedules, care must be taken in the selection of representative farms if aggregation error is to be minimized. Both seasonal and intra-seasonal demand schedules are presented since both are important when irrigation demand estimates are being developed.     

Implications of recent changes in Californian irrigation systems

This paper explains how, in view of competing demands for water in the western USA, the theme of water allocation and management has emerged as a vital political issue. In the Californian case, technical improvements in irrigation have extended the cultivated area and maintained productivity increases, and such developments have created the need for policy research. The author evaluates irrigation efficiency for both surface flow and sprinkler techniques, with particular reference to large-scale automated sprinkler systems, and concludes that a farmer's decision to apply developments in irrigation is strongly influenced by the requirements of energy conservation and efficient water management. The most significant issues likely to affect agricultural water demands over the next decade are identified.     

辽宁农业灌溉用水影响因素时空差异性研究

目的 文章基于2000—2019年辽宁农业灌溉用水相关数据，将农业灌溉用水压力、效率、用水价格、种植结构等因素纳入农业灌溉用水需求模型，估计各影响因素对农业灌溉用水需求的影响，更好地保障粮食和水资源安全。方法 利用时空地理加权回归模型研究辽宁各地级市农业灌溉用水影响因素作用的时空差异性。结果 （1）不考虑影响因素作用的时空差异性，用水价格和农村居民人均收入变动对辽宁农业灌溉用水需求的影响特别小。（2）考虑到影响因素作用的时空差异性，除了朝阳和大连，其余各地级市农业灌溉用水需求的价格弹性在2014年前后呈现出负向增大的态势，水价改革还有较大的效力空间。（3）辽宁农业灌溉用水效率和种植结构的回归系数在空间上呈现出中部低，四周高的特点。（4）城镇化程度对农业灌溉用水需求的影响呈现出由东北向西南逐渐递减，由正向较强逐渐向负向较强的演变。结论 依据辽宁农业灌溉用水的各影响因素的作用强度，种植结构、用水效率和城镇化程度是影响辽宁农业灌溉用水需求的主要因素，合理制定城镇化规划对该因素回归系数呈显著上升趋势的地级市尤为重要。     

甘肃省节水灌溉浅议

阐述甘肃省节水灌溉的必要性和紧迫性,并针对甘肃省的自然、土壤等情况,分析了不同地区应采取的节水灌溉模式,对比了节水增产效益,提出提高水的利用效率、改进田间灌水技术、推广田间保墒技术等加快节水灌溉的措施。     

灌溉用水权确权到户有关问题的思考

灌溉用水权确权到户是水资源资产管理的重点与难点,涉及数亿农户的权益,有关工作仍处于早期探索阶段。在大量调研的基础上,对该不该、能不能确权到户,管理能否到位等关键问题进行了探讨。研究认为:从国家发展战略、政策导向、技术流程、供水管理等多个视角考虑,灌溉用水权应当尽快确权到户,技术上完全可行,服务管理可以基本得到保障。建议将灌溉用水权确权到户作为新时代深化水利改革的重要内容,与农业水价综合改革、规范取水许可等工作有机结合,积极稳妥有序推进。     

农业灌溉水费“暗补”改为“明补”的必要性与可行性

通过梳理国内外水价政策,得到以下启示：对农业灌溉水费实行单纯的＂暗补＂是低效的,与我国的水资源形势不相适应;对农业灌溉用水实行＂明补＂是改变农业用水低效的最有效方式,应改变我国农业灌溉不收水费的＂暗补＂方式,实施水费征收与补贴并举。分析了农业灌溉水费＂暗补＂改为＂明补＂的必要性和可行性,并以河北省衡水市桃城区实施＂提补水价＂节水激励机制、节水效果明显为例,说明农民易于接受水费征收与补贴并举的方式。     

Water use and salinity in the Murray–Darling Basin: A state-contingent model*

The supply of water for irrigation is subject to climatic and policy uncertainty. The object of the present paper is to show how the linear and non-linear programming models commonly used in modelling problems such as those arising in the Murray–Darling Basin may be adapted to incorporate a state-contingent representation of uncertainty. Estimates showing the potential value of improved water use are also derived.     

我国农业现代化发展与农村水利建设关系的研究

[目的]研究我国农业现代化发展与农村水利建设之间的关系。[方法]文章以2009—2015年农业和水利建设有关数据构建回归分析计量模型,以农业现代化水平、人均耕地灌溉面积、水利建设投资完成额、水库容量和除涝面积为指标,具体研究了我国农业现代化发展与农村水利建设的关系。[结果]研究发现人均耕地灌溉面积、水利建设投资完成额、水库容量、除涝面积和农业现代化水平均有正向促进作用,所以农业现代化发展和农村水利建设也具有正向促进作用。[结论]由此研究认为应持续加强农村水利基础建设并提供有效供给,确保现代化农业产出水平稳步提升;总结和推广先进国家和地区水利发展经验,探索适合我国的农村水利发展道路;优化农村水资源配置,提高农村水利服务精准性,增强农业现代化背景下的农村水利供给能力,使两者在发展中相互促进,确保农业现代化的早日实现。     

新疆生产建设兵团各师灌溉水价变动对

以新疆生产建设兵团2000~2006年灌溉水价和与之对应的每公顷毛灌溉定额资料为基础,应用计量经济学需求函数模型,建立兵团灌溉水价与灌溉用水量的定量关系,利用以上研究成果对兵团灌溉水价改革进行预测,根据兵团各师农业灌溉节水量测算农业灌溉水价对农业经济的贡献率。结果表明,水价这一经济杠杆对当地农业经济的发展起到了促进作用。     

水利风景资源资产化管理初探

水利风景资源资产化管理既是水利行业对自然资产稀缺性凸显、生态产品需求趋旺的市场动态的主动把握,也是对党的"十八大"提出的"增强生态产品生产能力"的积极响应。水利风景资源资产化管理的目标是凸显水利风景区的生态、文化优势,全面实现水利风景区的物质产品、文化产品和生态产品的价值;难点是识别、展示水利风景区的生态系统服务,实现生态系统服务价值。水利风景资源资产化管理模式主要有:水库型、灌区型水利风景区的绿色农副产品开发,河湖型水利风景区的生态旅游发展,水保型水利风景区的生态补偿以及湿地型水利风景区的生态系统服务市场交易等。提出针对不同水利风景资源资产化管理模式应逐步配套不同的政策保障措施。     

Technology Adoption under Production Uncertainty: Theory and Application to Irrigation Technology

We propose a theoretical framework to analyze the conditions under which a farmer facing production uncertainty (due to a possible water shortage) and incomplete information will adopt a more efficient irrigation technology. A reduced form of this model is empirically estimated using a sample of 265 farms located in Crete, Greece. The empirical results suggest that farmers choose to adopt the new technology in order to hedge against production risk. In addition, we show that the farmer's human capital also plays a significant role in the decision to adopt modern, more efficient irrigation equipment.     

湄公河流域水资源开发利用现状

根据湄公河流域自然特征、水资源现状、水利工程现状及规划资料,分析湄公河各流域国水资源开发利用特点及未来趋势,为湄公河水资源可持续开发利用及我国同湄公河各流域国开展相关合作提供最基本的依据。研究结果表明,湄公河水资源开发利用率呈上升趋势;老挝未来将加快水电开发节奏,其规划水电总装机容量占湄公河总装机容量的70.0%;泰国对湄公河水资源的开发利用主要体现在农业灌溉方面,未来泰国灌溉引水有增加的趋势;柬埔寨和越南分别在湄公河干支流上有水电工程规划,但柬埔寨的用水需求主要体现在为保证其洪泛区土壤肥力,对湄公河上游雨季充足的洪峰流量的需求,越南是湄公河流域灌溉面积最大的国家,其主要的用水需求是旱季湄公河三角洲灌溉需水。     

新疆农业灌溉用水效率提升潜力分析

在对新疆农业用水现状分析的基础上,通过构建基尼系数法分析新疆灌溉用水效率,表明农业灌溉用水配置较公平,但农业灌溉用水效率较低,提高农业灌溉用水效率可以提高节水能力。通过区域间灌溉用水效率提升潜力分析表明,新疆各地州之间的节水潜力差异极大,且新疆农业灌溉用水效率具有较大的提升潜力。