Block-Rate versus Uniform Water Pricing in Agriculture: An Empirical Analysis

In this article we adapt Burtless and Hausman's (1978) methodology in order to estimate farmers' demand for irrigation water under increasing block-rate tariffs and empirically assess its effect on aggregate demand and inter-farm allocation efficiency. This methodology overcomes the technical challenges raised by increasing block-rate pricing and accounts for both observed and unobserved technological heterogeneity among farmers. Employing micro panel data documenting irrigation levels and prices in 185 Israeli agricultural communities in the period 1992–1997, we estimate water demand elasticity at −0.3 in the short run (the effect of a price change on demand within a year of implementation) and −0.46 in the long run. We also find that, in accordance with common belief, switching from a single to a block-price regime, yields a 7% reduction in average water use while maintaining the same average price. However, based on our simulations we estimate that the switch to block prices will result in a loss of approximately 1% of agricultural output due to inter-farm allocation inefficiencies.     

农田水利设施建设制度的变迁与匹配性分析——以中国封建时期农田水利设施建设与治理为例

农田水利设施建设的成功取决于有效的制度保障,而有效的制度安排则取决于"基础设施属性—参与者特质—制度环境"三个要素之间的匹配,中国古代农田水利设施的发展历程便证明如此。对于中国新时期的农田水利设施建设,本文提出相应的制度安排,即大型灌区灌溉设施的集权型制度、小型灌溉设施的农民自治制度以及类经济自立型排灌区的混合型制度安排。     

Adoption of improved irrigation and drainage reduction technologies under limiting environmental conditions

Modern irrigation technologies have been suggested as a means of conserving scarce water and reducing environmental pollution caused by irrigated agriculture. This paper applies an economic model of technology selection that provides a general framework to analyzing adoption of irrigation technologies under various environmental conditions. Data from the San Joaquin Valley of California is used to verify the theoretical relationships. Results suggest key variables to be considered by policy makers concerned with adoption of modern irrigation technologies. Among these variables are crop prices, water technology costs, farm organization characteristics, and the environmental conditions of the farm or the field. Policy implications were discussed and analyzed.This research was conducted while the first author was a visiting scholar with the Dept. of Agricultural Economics, University of California, Davis, and USDA-ERS, USA.     

淠史杭灌区水利建设与管理的思考

摘要：水利是现代农业建设不可或缺的首要条件,是经济社会发展不可替代的基础支撑。农田水利基础设施是提高农业生产力的物质基础。淠史杭灌区六十年来,在基础设施建设与综合管理中取得了长足的发展和进步。文章通过调查,分析了淠史杭灌区水利建设60年来的成功经验,剖析了其建设和管理中所存在的问题,并从建设过程和建成后管理两个角度提出了一系列相关的对策。     

Measuring Production and Irrigation Efficiencies of Rice Farms: Evidence from the Punjab Province,Pakistan

We employ a non‐parametric approach, data envelopment analysis, to estimate the technical and irrigation efficiency of rice farms in the Punjab Province of Pakistan. We use a cross‐sectional dataset of 80 rice growers, including 45 tube‐well owners and 35 water buyers. Mean technical efficiency scores show that tube‐well owners and water buyers are operating at fairly high efficiency levels, indicating that access to technology is not a major constraint. However, irrigation inefficiency is pronounced, with water buyers being more inefficient than tube‐well owners. A bootstrap truncated regression is used to investigate the determinants of technical and irrigation efficiency. We suggest that groundwater management policies should be designed to address efficiency enhancing factors such as knowledge of crop water consumption requirement, better credit opportunities, outreach extension services and training programs.     

灌片节水配套改造工程的必要性和可行性研究

文章以4个灌片为例,探讨了灌片节水配套改造工程的必要性和可行性。通过对项目区渠系水利用系数极低、实灌面积严重缩减以及水资源供需平衡进行分析,得出灌片节水配套改造工程的必要性;通过对典型工程的实际设计,得出灌片节水配套改造工程的可行性。     

Impacts of climate change on lower Murray irrigation*

This article evaluates irrigated agriculture sector response and resultant economic impacts of climate change for a part of the Murray Darling Basin in Australia. A water balance model is used to predict reduced basin inflows for mild, moderate and severe climate change scenarios involving 1, 2 and 4°C warming, and predict 13, 38 and 63% reduced inflows. Impact on irrigated agricultural production and profitability are estimated with a mathematical programming model using a two‐stage approach that simultaneously estimates short and long‐run adjustments. The model accounts for a range of adaptive responses including: deficit irrigation, temporarily following of some areas, permanently reducing the irrigated area and changing the mix of crops. The results suggest that relatively low cost adaptation strategies are available for a moderate reduction in water availability and thus costs of such a reduction are likely to be relatively small. In more severe climate change scenarios greater costs are estimated. Adaptations predicted include a reduction in total area irrigated and investments in efficient irrigation. A shift away from perennial to annual crops is also predicted as the latter can be managed more profitably when water allocations in some years are very low.     

漳河水库灌区节水发展策略

漳河水库灌区人均与单位农田灌溉面积水资源占有量均低于全国和全省平均水平40%以上,是水资源比较紧缺的地区。但灌区水资源利用率低,用水浪费的问题依然存在,与节水先进地区相比存在较大差距,具有一定的节水潜力。从提高全民节水意识,推进节水型社会建设步伐,走可持续发展道路的目的出发,全面总结了灌区用水现状,分析了节水工作中存在的主要问题,提出了以灌区水资源可持续利用支撑经济社会可持续发展的节水策略,并制定了节水实施保障措施。     

虚拟水方法在干旱地区灌澌工程中的应用——以西藏拉洛水利枢纽及配套灌区工程为例

通过应用虚拟水及其理论，对西藏拉洛水利枢纽及配套灌区工程的灌区进行水足迹及相关指标的计算，结果表明：灌区在工程设计基准年总水足迹为33960245m^3，其中农作物生产耗水占87.31％；灌区的人均水足迹为1958．153m^3，与单位农作物的虚拟水含量一样都高于全国平均水平；由于农业生产对灌区水资源造成了很大的压力，建议干旱地区的水资源利用要采取符合当地实际的虚拟水战略。