The role of common pool problems in irrigation inefficiency: a case study in groundwater pumping in Mexico

Groundwater depletion is a serious problem in Mexico. Several policy alternatives are currently being considered in order to improve the efficiency of irrigation water use so that extraction of groundwater is diminished. An understanding and quantification of different sources of inefficiency in groundwater extraction is critical for policy design. Survey data from a geographically extensive sample of irrigators is used to gauge the importance of common pool problems on input‐specific irrigation inefficiency. Results show that mechanisms of electricity cost sharing implemented in many wells have a sizable impact on inefficiency of irrigation application. Moreover, irrigation is very inelastic to its own unitary cost. Therefore, results suggest that policies aimed at eliminating electricity cost‐sharing mechanisms would be significantly more effective than electricity price‐based policies in reducing irrigation application. Results also show that well sharing does not affect groundwater pumping significantly, suggesting either a limited effect of individual pumping on water level or absence of strategic pumping by farmers sharing the wells.     

Forty years of irrigation development and reform in China

This study reviews 40 years of irrigation development in China including the transformation of the institutional and incentive structures in irrigation management. After rural reforms in the 1970s, irrigation investments slowed until the late 1990s. In North China, farmers became major investors in groundwater irrigation, leading to property rights’ transfer of tube wells from collective to private ownership. Despite positive effects in cropping patterns, farmer income and development of groundwater markets, privatisation has accelerated groundwater table deterioration. Since the middle of 1990s, Water User Associations have replaced village collective management of surface irrigation. This approach was adopted by most provinces by early 2001 with mixed results; only institutions with water‐saving incentives realised efficient irrigation. The Government is reforming water price policies to provide water‐saving incentives to farmers while not hurting their income. While China has focused on water rights and markets, and despite regulations and pilot projects, full implementation of water rights has been slow. Research reveals greater policy scope for expanding irrigation technologies that generate real water saving to rural areas. Given pressure associated with water scarcity and concern for food security, further effective reforms in irrigation and policy incentives are expected. The Government has also initiated some pilot projects to resolve increasing water scarcity problems through adjusting agricultural production activities.     

Impacts of changing water inflow distributions on irrigation and farm income along the Drâa River in Morocco

Irrigation water is essential for agriculture in the arid Drâa River basin in Morocco but climate change leads to increasingly unreliable water supply in the area. This article analyzes impacts of changing water inflow distributions on irrigation and farm income extending a conjunctive river basin model toward a stochastic modeling approach. Regional climate scenarios are used to derive a maximum likelihood density estimate of current and future water supplies. Based on these distributions, Monte Carlo simulations are performed to obtain stochastic model results on surface and groundwater irrigation as well as economic indicators for six oases along the river. The probability of farmers to receive revenues below the subsistence level is around 2% under current conditions, but this is likely to rise to rates of 6% to 15% depending on the underlying climate change scenario. The composition of water sources for irrigation will shift to more groundwater use. The river basin model is able to represent complex spatial interactions between oases as well as a partial complementarity between groundwater and surface water irrigation due to salinity management effects. Interestingly, the value of groundwater is not necessarily increasing under future climatic conditions as salinity problems are aggravated with expanded groundwater use.     

Rice productivity in Bangladesh: What are the benefits of irrigation?

Green Revolution technologies transformed Bangladesh’s agricultural system through the introduction of high-yielding rice and wheat varieties, chemical fertilizers and pesticides, and the expansion of tubewell-irrigated area, enabling crop production during the dry season. However, serious challenges continue to plague the agriculture sector, including scarcity of land due to high population density, unbalanced use of fertilizers and pesticides, and great variation in water supply across seasons – from drought to stagnant flood conditions. Further expansion of irrigated area – including through the continued development and improvement of surface water systems – is being eyed by Bangladesh’s Ministry of Agriculture to address many of the remaining challenges facing the country. However, such expansion is not without risks or consequences, and a careful analysis of who benefits from irrigation, and how, must guide development priorities.We examine plot-level data for rice production during Bangladesh’s three rice seasons – aus, boro, and aman – across a nationally-representative household survey in Bangladesh. While rainfall is the most important determinant of rice yield during aus and chemical inputs are most important during aman, access to irrigation has the greatest influence on boro rice yield during the dry season, particularly for the coastal south. The government of Bangladesh is planning massive investments in the southern region for the improved provision of surface water irrigation. The expected decline in groundwater, coupled with our econometric findings, suggests that expanding boro production in the south may not be a good strategy to promote, for the region. Whether brackish shrimp aquaculture can provide an equitable and sustainable livelihood alternative should continue to be a focus of research.     

Non–Market Interventions in Water–Sharing:Case Studies from West Bengal, India

This paper deals with two issues that are important areas of concern in the recent literature on water management in less–developed countries: forms of ownership of groundwater resources and alternatives to anarchy in the exploitation and use of groundwater. The emergence of a market for irrigation water has been argued to have the potential to provide irrigation water to large numbers of small cultivators in developing countries. The development of free markets for water, however, has also been shown to be associated with the emergence of 'water–lords' and with contracts for the purchase and sale of water that are biased against the poor. By contrast, this paper presents two examples of viable non–market interventions in water–sharing – regulation of water markets by village councils and cooperative tubewell groups – from villages in West Bengal, India. These interventions both improved the efficiency of water–use and represented relatively equitable arrangements for water–sharing.     

圆形喷灌机节水示范区效益评价与分析

计算了圆形喷灌机节水示范区灌溉工程的建设投资费用、年运行费用和效益,并对其进行国民经济评价和社会效益、生态效益分析。结果表明,与地面传统灌溉方式相比,采用圆形喷灌机进行灌溉可以减少劳动强度,提高工作效率,增加作物种植收益,产生显著的经济、社会和生态效益。     

干旱区流域地下水生态调节与监测预警研究

[目的]干旱区流域地下水资源与生态环境具有紧密的响应关系。塔里木河流域是我国典型的干旱荒漠区,研究地下水对生态的调节功能以及对地下水的监测预警,对干旱区流域可持续发展具有重要的作用。[方法]根据流域地下水自动监测系统的长期监测,研究选取塔里木河上游阿拉尔、新渠满,中游英巴扎,下游恰拉、阿拉干共5个断面31眼监测井进行地下水位检测。[结果]监测显示,塔里木河流域上、中游的地下水位良好,下游地下水位较低,生态环境脆弱;地下水位最低值与最高值一般均出现在7~9月,对生态环境具有强烈的影响。[结论]根据对塔里木河流域地下水位的监测预警,为了更加有效地保护塔里木河流域地下水,要处理好流域地下水开发、保护与生产、生态用水之间的关系,提高用水效率,禁止开荒扩大生产,严格管理地下水开采,保护好地下水水质,加大对流域下游的生态输水,逐步恢复下游生态环境。     

Valuing groundwater recharge through agricultural production in the Hadejia-Nguru wetlands in northern Nigeria

This study applies a production function approach to value the groundwater recharge function of the Hadejia‐Nguru wetlands in northern Nigeria. The groundwater recharge function supports dry season agricultural production which is dependent on groundwater abstraction for irrigation. Using survey data this paper first carries out an economic valuation of agricultural production, per hectare of irrigated land. We then value the recharge function as an environmental input into the dry season agricultural production and derive appropriate welfare change measures. Welfare change is calculated using the estimated production functions and hypothetical changes in groundwater recharge and hence, groundwater levels. By focusing on agricultural production dependent solely on groundwater resources from the shallow aquifer, this study establishes that the groundwater recharge function of the wetlands is of significant importance for the floodplain.     

宁夏固海灌区可持续发展的思考

在总结宁夏固海灌区经济效益的基础上,分析了灌区多年来的用水量状况和灌区供水存在的主要问题。针对灌区运行管理中存在的问题,提出了增强运行管理单位的造血功能,创建多元化的供水市场,建立合理的水价机制,政府给予必要的扶持政策等建议。     

The allocative efficiency and conservation potential of water laws encouraging investments in on-farm irrigation technology

Agricultural water conservation statutes are emerging in the West encouraging private irrigators to improve on‐farm irrigation efficiency as a basinwide conservation measure. We investigate whether private improvements promote the economic efficiency and conservation of water use basinwide under a wide variety of hydroeconomic circumstances. The standard of efficiency is how an irrigation district manager should optimally invest in improving the irrigation efficiencies of individual farms located along a stream while internalizing intrabasin allocative externalities of these investments. The results indicate that the popular Oregon legislative model may be the least effective in conserving water and promoting economically efficient water allocation.     

An Economic Analysis of Groundwater Contamination from Agricultural Nitrate Emissions in Southern Ontario

This paper analyzes the costs and benefits of controlling groundwater pollution from agricultural use of nitrogen fertilizer in southwestern Ontario. The Village of Hensall, where nitrate concentrations have been observed above 10 mg/L in recent years, is selected as the study site.'The CREAMS simulation model is used to estimate the effect of reducing nitrogen fertilizer on nitrate leaching and consequently on nitrate groundwater pollution. Estimates of the value of groundwater are obtained from the literature and are used to calculate the off-farm cost of groundwater contamination. This procedure results in a wide range of values for the benefits of reducing nitrate pollution. Estimated annual benefits of improved ground-water quality range from less than $1,000 to more than $30,000 for the village. The off-farm benefits of nitrate groundwater pollution abatement outweigh the cost of using bottled water and also exceed the on-farm cost of reducing nitrogen fertilizer application rates. Placing a tax on nitrogen fertilizer would reduce the level of nitrogen applications, but the farm cost of compliance to a nitrogen tax policy is substantially higher than the compliance cost under a regulatory policy that imposes a quantitative ceiling on nitrogen application rates over the part of the aquifer from which the village draws its water supply.     

Groundwater Management: Efficiency and Equity Considerations

Groundwater has the characteristics of commonly owned property, and its use is likely to be inefficient in the absence of regulation. Several management tools can be used to regulate groundwater withdrawals, with no one tool dominating the others in terms of efficiency of water use. However, the welfare distributional effects of various management schemes on individual users who vary in their derived demands for groundwater might be quite substantial, and different users may find considerably different schemes attractive. The equity problems associated with the division of management benefits may dominate the decisions about support of or opposition to groundwater management, and hence they must be undertaken with considerable care and resolved by consensus among users. Although the negotiations are expected to be extensive and complicated, there is a substantial basis for agreement because all users stand to gain; the question is, who will gain the most?     

Evaluation of drought management in irrigated areas

This paper focuses on the economic consequences of droughts for the irrigation sector. We develop a dynamic‐recursive mathematical programming farm model that assumes imperfect mobility of capital and labour as well as rational expectations about future water availability. The model is calibrated to 12 representative farms belonging to three irrigation communities of the Guadalquivir Basin (south Spain) and used to simulate the 1991–1997 period, which included 3 years of intense drought. Results indicate that the drought imposed significant costs on farmers, but show also that water managers partly exacerbated these costs by allocating excessive amounts of water to irrigators in the abundant years. The model is also used to evaluate the benefits of a perfect water supply forecast and to simulate the economic gains of a voluntary water banking scheme. Results show that the benefits resulting from the perfect forecast of water supply 1 year ahead would represent a relative gain of 5%. However, a voluntary banking system would allow farmers to increase their benefits by 32–82% depending on the supply system.     

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。     

Golf course irrigation and self-sufficiency water in Southern Spain

During the first decade of the 21st century, many golf courses were developed in the Southeast of Spain, which greatly increased the number of these facilities. Almost all of these golf courses have been accompanied by large residential developments composed of thousands of dwelling units. This article seeks to identify the factors that influence golf courses’ water consumption and estimate the number of dwelling units that an associated residential development needs to have to provide the effluent necessary to fully meet the irrigation needs of a golf course. The study indicates that private golf courses achieve greater levels of irrigation efficiency than public golf courses and that the golf courses associated with residential developments subject the irrigation needs of the grassland to the sale requirements of the real estate properties. The study also estimates that a golf course requires approximately 3000 dwelling units with an average annual occupancy of 33% to achieve self-sufficiency for irrigation.     

Valuing financial,health, and environmental benefits of Bt cotton in Pakistan

Data from a farm survey and choice experiment are used to value the benefits of Bt cotton in Pakistan. Unlike previous research on the economic impacts of Bt, which mostly concentrated on financial benefits in terms of gross margins, we also quantify and monetize health and environmental benefits associated with technology adoption. Due to lower chemical pesticide use on Bt cotton plots, there are significant health advantages in terms of fewer incidents of acute pesticide poisoning, and environmental advantages in terms of higher farmland biodiversity and lower soil and groundwater contamination. Farmers themselves value these positive effects at US$ 79 per acre, of which half is attributable to health and the other half to environmental improvements. Adding average gross margin gains of US$ 204 results in aggregate benefits of US$ 283 per acre, or US$ 1.8 billion for the total Bt cotton area in Pakistan.     

农户灌溉用水的效率差异——基于甘肃、内蒙古两个典型灌区实地调查的比较分析

本文根据甘肃省张掖市与内蒙古自治区包头市典型灌区2007年的农户调查数据,基于单一投入要素技术效率测定理论,运用数据包络分析(DEA)方法客观评价被调查农户灌溉用水效率,并对两个典型灌区农户在灌溉用水方面存在的效率差异进行比较分析。研究表明,农户的生产目的、收入水平及来源、种植业能力等家庭特征,配水、输水设施条件与灌溉方式等生产条件与价格水平、水权安排等用水管理制度因素是导致农户灌溉用水效率差异的主要原因;发展农户参与式灌溉管理模式、优化水资源管理体制、扩大市场在农业水资源配置中的作用、强化农田水利基础设施建设、建立灵活便捷的灌溉供水系统是微观层面农业用水效率提高的关键。     

Evaluating irrigation investments in Malawi: economy‐wide impacts under uncertainty and labor constraints

Irrigation expansion is critical to increase crop yields and mitigate effects from climate change in Sub‐Saharan Africa, but the low profitability has led to little irrigation investments in the region so far. Using an integrated modeling framework, we simultaneously evaluate the returns to irrigation arising from both economic and biophysical impact channels to understand what determines the profitability of irrigation in Malawi. Our results confirm that the returns to irrigation cannot cover the costs in Malawi. While labor‐intensive irrigation expansion leads to unfavorable structural change in the short‐run, the profitability hinges on low irrigated yields that fall far from expectations due to insufficient input use and crop management techniques. On the other hand, we find that the nonmonetary benefits of irrigation regarding higher food security, lower poverty, and reduced vulnerability to climate change make investments in irrigation worthwhile to improve the livelihoods of smallholders.     

Mathematical optimisation of drainage and economic land use for target water and salt yields*

Land managers in upper catchments are being asked to make expensive changes in land use, such as by planting trees, to attain environmental service targets, including reduced salt loads in rivers, to meet needs of downstream towns, farms and natural habitats. End‐of‐valley targets for salt loads have sometimes been set without a quantitative model of cause and effect regarding impacts on water yields, economic efficiency or distribution of costs and benefits among stakeholders. This paper presents a method for calculating a ‘menu’ of technically feasible options for changes from current to future mean water yields and salt loads from upstream catchments having local groundwater flow systems, and the land‐use changes to attain each of these options at minimum cost. It sets the economic stage for upstream landholders to negotiate with downstream parties future water‐yield and salt‐load targets, on the basis of what it will cost to supply these ecosystem services.