水价政策对农户灌溉用水行为的影响——基于农户行为模型的理论分析

水资源用水总量控制与定额管理相结合的制度已成为我国水法的重要制度.但是定额管理制度的实行必须与水价政策相结合才能有效地激励人们节约用水,而且不同的水价政策对人们用水行为的影响也可能存在差异.通过建立农户灌溉用水行为模型,利用比较静态分析方法分析单一水价与超定额累进加价这两种水价政策对农户用水行为的影响.分析表明,单一水价与超定额累进加价均会激励农户采用灌溉效率高的灌溉技术或对农户的种植面积和种植结构产生影响并对当地的农地流转市场产生影响.进一步的分析表明,超定额累进加价政策对农户行为的影响更大,但其有效性取决于合理的定价.     

北京市用水结构预测分析

城市化进程给城市用水量与用水结构带来了显著的改变,通过研究北京市用水结构的发展趋势,为区域水资源的科学管理与合理配置提供依据.用水结构主要包括农业用水、工业用水、生活用水和生态用水四类,可将历年用水量作为一系列按照时间顺序排列的成分数据,运用球坐标变换的成分数据预测方法,研究了北京市用水量结构的动态规律,并对未来两年的用水量结构作出预测.     

基于水量水质耦合多目标模型的辽源地区水资源优化配置

对水资源进行优化配置是解决社会经济发展与水资源可用量紧张的有效手段.采用区域水质—水量耦合水资源优化配置模型,以吉林省辽源市2010年数据为基准,对2020年水资源配置进行优化预测.研究结果表明,辽源市在规划期内"三生"用水结构由89:10:1调整到81:18:1.其中生产用水中第一产业用水量下降2.17%,第二产业用水总量下降2.78%.第三产业用水量提升4.29%,同时降低了水污染的排放.优化方案可有效降低辽源市水资源消耗与水环境污染,为水资源的可持续利用提供了有效的技术支持.     

可变模糊集理论在江西省水资源承载力评价中的应用

结合江西省2009年自然、社会和经济以及水资源资料,选取降水量、灌溉率、水资源开发利用程度、生活用水定额、人均供水量、万元GDP用水量、生态环境用水率、缺水率作为评价指标,应用可变模糊评价模型对江西省11个市的水资源承载力进行了评价研究.能够科学、合理地确定样本指标对各级指标标准区间的相对隶属度、相对隶属函数,并且能够通过变化模型及其参数,合理地确定出样本的评价等级,提高对样本等级评价的可信度.最后与模糊识别理论计算出的结果进行比较,评价等级基本保持一致.研究结果表明,江西省整体水资源承载力等级为1~2级,水资源开发利用已具有一定规模,部分区域水资源开发潜力较大.     

基于二层规划的流域水资源交易决策模型

对于一个流域而言,解决水资源短缺及污染最为有效的经济手段是建立以流域统一管理为基础,兼顾水权交易和排污权交易的市场体系.在水交易市场运作过程中存在着流域管理机构和具体用户之间的利益矛盾,为此本文构建了以流域管理机构作为流域水资源系统整体计划、控制和协调中心的上层决策者,各用户作为具有相对自主权的下层决策者的决策管理机制,并利用二层规划方法对流域水资源的交易进行建模研究,期望实现流域水资源的最优分配.最后,应用算例验证了模型及求解方法的可行性和有效性.     

天山北坡经济带农户借款行为的影响因素研究

基于对天山北坡经济带450个家庭的调查数据,通过构建双变量logistic模型,对该地区农户正规金融与非正规金融借款行为的影响因素进行估算.研究得到以下基本结论:1)影响农户借款行为的关键性和主要因素是农户家庭的特征;2)金融环境对农户借款行为影响显著;3)受民族聚居的影响,民族这一因素对地区农户借款的可获得性有所差异,对非正规金融借款行为的影响度高于对正规金融借款行为的影响.     

耕地面源污染与农户经营行为典型关系的实证研究

考虑到果蔬茶等农业产业耕地面源污染日益严重,基于新疆甜瓜种植农户调研数据,运用典型相关分析模型,对农户经营行为与耕地面源污染的关系进行实证分析.研究结果显示,新疆耕地面源污染与农户经营行为具有典型的相关关系,新疆耕地面源污染中最主要的是农膜污染,其次是化肥污染和农药污染;转变农户生产经营行为方式是实现农业面源污染防治的重要途径,通过提高农户组织化程度,推进土地流转和农地确权,扩大农业经营规模化、专业化等方式可以有效减少耕地面源污染.     

农产品电商对农户有机肥施用行为影响研究——基于农户绿色认知的中介效应

阐释了农产品电商对农户有机肥施用行为的影响机制,并引入农户绿色认知变量,根据四川、陕西两省686户猕猴桃种植户的调查数据,通过主成分分析确定农户绿色认知指标体系-农户政策认知、责任认知和环境认知,运用Bootstrap中介效应模型实证验证了农产品电商对农户有机肥施用行为的影响以及农户绿色认知对农产品电商影响农户有机肥施用行为的中介效应.实证结果表明:农产品电商对农户有机肥施用行为产生显著正向影响,且通过绿色认知的部分中介效应间接影响农户有机肥施用行为.其中,农户政策认知在农产品电商和农户有机肥之间存在部分中介效应,占总效应的比重为87.91%,农户责任认知具有完全中介效应,农户环境认知不存在中介效应.基于此,分别从农产品电商和农户绿色认知层面提出相应政策建议.     

北京城市水资源供需系统研究

在研究北京市水资源供需现状的基础上,采用系统动力学方法构建了城市水资源供需模型.利用系统思考中学习型组织的信息反馈回路模式,引入基于可持续发展系统生存回路的水资源供需平衡指标,采用反映供需关系紧张的水供需一次、二次平衡作为衡量地区水危机的变量.按照人口增长与人均综合用水定额不同组合下的城市水需求总量,得到未来北京市水资源供需平衡变化的四种情境,通过动态模拟,分析不同情况下满足水需求的供应方案.结果显示,北京市现有的水资源条件与城市发展需水要求还有较大距离,应在挖掘本地水资源的基础上,依靠南水北调工程等境外调水,解决地区缺水的矛盾.     

不同禀赋农户对信息服务技术采纳行为的对比分析

首先指出了农村地区存在的信息化不平衡现象,并提出需要针对不同农户的禀赋特征研究他们的采纳行为.为了研究不同禀赋农户的采纳行为,结合层次聚类和K-均值聚类,根据学历、收入和农地大小将农户分为高禀赋和低禀赋两组,利用扩展的技术接受模型研究了不同禀赋农户对于短信定制服务的采纳行为.研究结果表明低禀赋农户更容易受到可试性、感知易用性和成本的影响,而主观规范、网络外部性和感知有用性对不同禀赋农户的影响并没有显著区别.     

Modeling voluntary participation in a cost‐sharing agricultural water quality management program

This economic analysis of farmers' voluntary adoption of water quality management alternatives integrates three biophysical simulators to predict crop yields and soil erosion/water quality impacts under uncertain weather and market conditions. Farmers' willingness to costshare was used to estimate expectations of net returns and associated water and soil pollution based upon government costshare scenarios. Simulations integrated into mathematical programming results indicate that irrigation and nitrogen fertilizer applications do not alter water quality in the Gum Creek Watershed as much as generally anticipated. Under limited government payments, pollution abatement through reduction of irrigation and/or nitrogen fertilizer applications significantly reduces farmers' net revenues and hence, without threats of other regulatory means, more farmers opt out of a voluntary program. Abatement of nitrogen runoff and leaching should consider other management alternatives and include nonagricultural sources of pollution.     

OPTIMIZING THE PERFORMANCE OF IRRIGATED AGRICULTURE IN EASTERN ENGLAND UNDER DIFFERENT WATER PRICING AND REGULATION STRATEGIES

Irrigation water shortage is becoming an increasingly serious problem in agricultural production. Growing pressure on water resources is leading to increasing restrictions on abstraction for irrigation and consideration of the use of economic instruments, such as increased abstraction charges and/or tradable licences, to restrict demand and encourage wiser use of water. We evaluate irrigation using selected economic, social, and environmental indicators of performance, including the value of water used for irrigation. A linear programming model is developed and used to simulate possible responses by irrigators and the impact on irrigation performance of intervention measures, namely abstraction quota restrictions and volumetric pricing that might be used to ration water and/or increase water use efficiency. Through the use of parametric programming a scenario analysis is performed to a case study in eastern England with regard to perturbations of irrigation water under alternative policy instruments.     

A mathematical programming model applied to the study of water markets within the Spanish agricultural sector

Spanish irrigated agriculture uses about 80% of all the nation's available water resources. The need to increase the economic efficiency of current uses of water in the agricultural sector is perceived as the top priority of the country's national water policy. In Spain surface water is centrally allocated among competing users based on allocation criteria dictated by the Water Law. The complete absence of price or market signals is a major obstacle to induce irrigators to use water more efficiently. Water markets within the agricultural sector is a promising, though scarcely analyzed in Spain, solution to increase its economic efficiency. This research is an attempt to evaluate probable water transfers among farmers and irrigation districts as well as water price equilibria resulting from different water market arrangements. Three interconnected mathematical programming models permit the simulation of water use at the farm level and water market arrangements in the Guadalquivir Valley (Spain). Results show that water markets would be highly dependent on the level of transaction costs and on the relative reductions of water allotments due to nonoverlapping drought cycles among water districts.     

基于主成分分析的需水量预测模型研究

用水是整个水资源系统中的一个重要环节,需水预测是制定水资源规划、管理以及国民经济计划的基础和依据.提出了基于主成分分析法分析的需水量预测模型,试图能探讨需水定额与经济社会各影响关系响应,以郑州市为例对2010年、2020年和2030年的工业、农业和生活的需水量进行了预测,并与郑州市水资源规划的预测结果进行了比较,分析及比较结果表明:该模型预测结果比规划结果偏低,2010年、2020年和2030年平水年分别需水162295×104m3、179966×104m3和194696×104m3,需水结构的变化基本反映了郑州市产业结构调整和社会经济良性发展的趋势.     

Individual transferable vessel quotas and efficient restructuring of the primary harvesting sector

Over the last three decades most of the world's fisheries have been subject to management programs that have tried to limit the use of key fishing inputs. Inevitably, these restrictions have proven ineffective at preventing rent dissipation and stock depletion. More noteworthy is that fishers have subverted the intentions of these restrictions by adjusting the primary harvesting technology. This has led to an inefficient industrial structure characterized by capital stuffing on the part of each vessel, excess employment, an inefficient mix of vessels in the fleet, and too many vessels altogether.A promising means of encouraging more efficient primary harvesting is the individual transferable vessel quota that allocates a given catch to each vessel, thereby giving an incentive to catch the quota at least cost. This paper examines efficiency gains and potential industry restructuring from the introduction of an ITVQ into a fishery that was previously subject to input restrictions.Using data from the British Columbia salmon fishery, this paper estimates restricted cost functions for each of four different vessel types and simulates the operations of a market for ITVQs. The demand for quota comes from individual vessels and is found by differentiating the cost function with respect to the shadow price of quota. The market for quota is in equilibrium when the total demand for quota is equal to the fixed supply of quota set by the government. This implicitly defines the equilibrium quota rental price. Results show that the ITVQ could generate unit rental prices for quota between 31 and 93 cents per pound (18–53% of the average landed price).Using this simulated price, each vessel's costminimizing strategy is defined and both low cost vessels (those that will buy quota) and high cost vessels (those that will sell quota and exit the fishery) are identified. Quota trades between the two groups result in efficiency gains. These include reduced capital stuffing, exit of less efficient vessel types, attainment of economies of scale, and an efficient composition of vessel types in the fleet. In aggregate these gains lead to an estimate of annual resource rent that is approximately equal to one third of the value of the catch.     

The economics of water resources for the generation of electricity and other uses

An optimal control approach is used to analyze the tradeoff between the use of water resources for electricity generation versus other economic uses (irrigation, industry, etc.). For that purpose, a dynamic model is presented which establishes relationships between economic growth, water resources management, and energy policy in the context of the aforementioned tradeoff, in an economy whose energy matrix is heavily dependent upon hydroelectric power. Among other results, the analysis establishes that in the market, the price of water for non-energy uses should be twice the price of the energy goods, indicating the necessity of substituting other sources of energy for hydroelectric power.     

春小麦水分敏感指数与有限水量生育期的最优分配

通过不同的受旱处理，确定了Jensen模型中的春小麦水分敏感指数。介绍了运用生态规划模型实现有限水量生育期最优分配的方法与步骤，并以辽西地区春小麦为例，确定了不同初始含水量和生育期可利用灌溉水量下的最优分配决策。     

市场经济体制下水资源管理形式探讨

水资源管理是一个动态、多层次、复杂的系统工程。文章分析了传统的水资源管理体制存在的弊端,着重探讨了社会主义市场经济体制下应该采取的水资源管理办法,旨在促进水资源的可持续利用及国民经济和社会的可持续发展。