Cost-benefit analysis and ideas for cost sharing of groundwater irrigation: evidence from north-eastern Ethiopia

The government of Ethiopia has invested in groundwater development for smallholder irrigation in the Raya Valley and Kobo Valley, north-eastern Ethiopia, where the hydrogeological potential is large but not fully developed. A cost-benefit analysis shows that investment in deep groundwater irrigation development is viable at a 9.5% discount rate in 75% of the wells. Assuming full cost recovery of capital investment, the annual payment rates (annuity) that irrigation users should pay over the wells’ service life (25 years) were estimated. It is recommended that future investment be based on cost sharing rather than full cost recovery to facilitate uptake and address financial realities.     

The negative impact of subsidies on the adoption of drip irrigation in India: evidence from Madhya Pradesh

Abstract

Drip irrigation in India has expanded slowly. One reason cited is the high capital costs facing the smallholder-dominated agricultural sector. Governments have provided capital subsidies in response. This study finds that, rather than improving access to drip, the subsidy system holds the technology back, because its technical requirements, highly bureaucratic processes and pricing incentives turn many drip providers into rent-seeking agents rather than service providers to farmers, leading to price increases of 40% or more. If capital costs are truly the constraint on drip expansion in India, alternative models to address them are available.     

山西省地下水机井普查状况及其对策建议

通过对山西省地下水机井的普查,了解了山西省地下水资源开发现状,机井普查的数据也说明了机井超量开釆地下水带来的资源、环境、生态及管理问题,针对这些问题提出了相应的对策措施。     

Micro-irrigation development in India: an analysis of distributional pattern and potential correlates

ABSTRACT

In India, of late, micro-irrigation has received considerable policy focus. However, as of 2017, only about 10% of the potential area is under micro-irrigation. The present study analyzes the pattern and equity issues of distribution of micro-irrigation in India and identifies the potential correlates. The regression analysis reveals that the stage of groundwater development and agro-climatic differences significantly influence the spread of micro-irrigation. The relatively low spread of micro-irrigation in states with over-exploited groundwater needs attention. Overall, the study points to the need to revamp the current micro-irrigation development programmes, which focus excessively on subsidy.     

新的淡水水源——空气取水

介绍3种方法收集空气中的水资源:①制冷结露法,将湿空气温度降到露点以下,使其中的水蒸气结露而获得液态水;②吸附法,含湿空气流过吸附剂,其中的水蒸气被吸附,然后加热吸附剂使水分脱附,从而得到淡水;③聚雾取水法,将雾中小水滴分离出来的取水方法。为提高空气取水技术的取水率还需探讨含湿空气在甲虫背部的凝结析水机理和开发高效吸附剂。     

Poor state of irrigation statistics in India: the case of pumps,wells and tubewells

Groundwater is the main source of irrigation in India, but there is a huge uncertainty about the number of groundwater structures. This paper compares data from four government sources on wells and tubewells, diesel pumps and electric pumps for time periods from the mid-1980s to the mid-2000s. There is a wide divergence in data, which is not attributable to mere time lags or definitional differences. This is a cause for concern, because lack of reliable estimates of these numbers affects realistic calculations of important variables such as groundwater extraction, electricity subsidies, and the carbon footprint of agricultural groundwater use.     

Agricultural water and energy management in Tajikistan: a new opportunity

ABSTRACT

Agricultural water use in Tajikistan is largely based on mechanized irrigation pumps. The farming community cannot afford the cost of the energy used for pumping, resulting in large debts to the service provider. We propose limiting pumping facilities for five years in exchange for energy export to neighbouring countries. The energy export could cover the annual pumping expenditures, pay off agricultural debt and partly rehabilitate the irrigation network. We suggest three scenarios with different pumping energy reductions, and the relevant technical parameters of the set-aside scheme are assessed.     

Irrigation Development and Rural Poverty in Gujarat,India: A Disaggregated Analysis

Abstract

There has been renewed interest during recent times in the impact of irrigation development on rural poverty. For long, researchers asked whether irrigation development reduces the poverty of irrigators. However, the question being asked now is: does investing in irrigation—rather than in other public works—help reduce rural poverty in a region? Using Government of Gujarat's 1997 census of Below Poverty Line (BPL) households as well as the Village Amenity Survey of the same year, this paper explores the interplay between irrigation development and rural poverty in 177 predominantly rural talukas, which is an administrative unit with a population of around 100,000-150,000 people, of Gujarat state in western India. Our analysis shows that for the design of poverty-targeting programs, two variables have the highest appeal: primary education infrastructure and improved land productivity through irrigation. It also suggests that, over the long run, irrigation benefits far transcend the command areas of irrigation systems. As a result, irrigation impact studies focused at farm or command area level seriously underestimate overall livelihood impacts of irrigation development. This is because intensively irrigated areas act as magnets that attract rural poverty from their surround, especially from other dry areas. Population pressure on farm lands thus tends to get redistributed according to the carrying capacity of farm lands. Across 177 predominantly rural talukas of Gujarat, we find: a) an inverse relationship between land use intensity and land-man ratio; and b) as land productivity (output/hectare of net sown area) declines, output per rural person declines too, but far more slowly than would have been the case without the “magnet effect.”     

Appraisal and optimization of agricultural water use in large irrigation schemes: II. Applications

In this paper, the theoretical approach presented in Part I is demonstrated by means of case studies on the irrigation schemes of Rio Mendoza and Rio Tunuyán in the Province of Mendoza, Argentina. The object of the case studies was the determination of optimal allocation of surface water to reduce the use of groundwater. Current and optimal conjunctive allocation of ground and surface water is studied by means of the developed simulation and optimization models.The second case study was designed on the basis of the experience gathered during the first one: each step of the case studies is compared. The comparison between the two case studies illustrates how to apply the proposed approach when the amount and quality of available data are different. For the more detailed Rio Tunuyán study, we determined the following physical characteristics of all terminal nodes: on-farm rotational intervals, mean water application depth, actual soil water storage capacity, crop water requirements, depth of groundwater table, aquifer transmissivity, and efficiency of groundwater use.The performance of the entire system is sensitive to changes in the water application depth, as it was shown by a simulation study.The application of our optimization approach to the conjunctive use of ground- and surface water showed that the total water requirements over a year can be met by a reassignment of water that reduces the total costs of a great amount.     

Managed aquifer recharge in community water supply: the Finnish experience and some international comparisons

This paper analyzes the use of managed aquifer recharge (MAR) in community water supply in Finland and presents some international experiences for comparison. The framework of MAR consists of the natural environment and physical infrastructure, as well as socio-economic aspects, all of which are interrelated. Local conditions form the basis of an MAR system and to a large degree determine infiltration options and the most suitable methods. Finnish hydrogeology, climate and local conditions are highly comparable to those in Sweden but differ from those of other parts of Europe, Australia, the USA and Asia. This article provides a holistic view of MAR not only as a technical means of resource enhancement for water supply but also as an element interacting with the natural environment and society.     

断面水量分摊法及其在南水北调供水成本分摊中的应用

调水工程的供水成本一般按照各受水区段供水量所占比例分摊,当考虑输水损失后,因输水损失分摊方法的不同,会产生不同的分摊用水量数据,从而有不同的供水成本分摊方法。本文对折算水量分摊法进行改进,提出了断面水量分摊法,该方法将南水北调工程中的输水损失在本区段净供水量和向北供水量之间进行分摊,将输水损失的水量按照受水比例在本区段及以后各区段之间进行分割,根据流经受益各区段断面的水量比例来分摊供水成本。该分摊方法更符合调水的实际情况。     

Institutional organizers and collective action: the case of water users' associations in Gujarat,India

Setting up water users' associations (WUAs) and involving them in the management of delivery systems is an important innovation in improving the performance of public irrigation systems. Most Indian states are in a great hurry to turn over management of “below-the outlet” systems to WUAs. Yet the crucial link between the work done by the institutional organizers who set up these WUAs, the efficacy of the WUAs and the eventual performance of the irrigation systems remains unexplored. This paper attempts to explore this link. It shows that overdrive in the formation of WUAs may reduce their institutional sustainability.     

基于PCA和SVM的遥感影像水体提取方法及验证

针对内陆湖泊水质及光谱特性空间差异性大、支流水系结构复杂而导致的遥感影像水体提取精度低的问题,提出了结合光谱主成分分析(PCA)及支持向量机(SVM)的PCA-SVM水体提取算法。基于GF-1卫星遥感影像,对原始影像光谱波段特征进行PCA降维,从中优选熵、方差、差异性纹理特征向量,结合原始波段及归一化差分水体指数(NDWI),构建了8维特征向量,并基于SVM算法提取湖泊水体。以巢湖洪水期与非洪水期影像为研究实例,分别采用NDWI法、传统SVM算法及PCA-SVM算法对水体进行提取,并进一步基于PCA-SVM算法对2020年汛期巢湖洪水期淹没演变过程进行反演和跟踪,定量解析特征向量组合及SVM惩罚系数C对水体提取性能的影响。结果表明：PCA-SVM算法提取的湖泊完整、支流连续,显著改善了含蓝藻水体漏提、建筑物误提等问题;洪水期和非洪水期提取结果的F1分数分别为95.08%和97.95%,虚警率分别为5.43%和1.13%,提取精度显著高于NDWI法和SVM算法。     

Farmer heterogeneity and water pricing reform: a case study from Vietnam

Water pricing has been recognized as an important policy instrument for improving the efficiency of irrigation and underpinning the sustainability of related services. However, establishing and charging the ‘right’ price is no simple task. This paper uses an exploratory factor analysis to isolate farmers’ motivations towards farming. A binary logit regression is then used to examine the relationship between motivation, household, and farmer characteristics and willingness to pay for improved irrigation services. Findings from this study suggest that a ‘one size fits all’ approach faces remote prospects of success and better targeting of reform effort is warranted.     

An inquiry into collective action and sustainable participatory watershed management: evidence from Southern India

Policies of devolution have been widely adopted in both developing and developed countries. This study investigates how the devolutionary policies ensure collective action in watershed management. It examines the factors that affect collective participation in watershed management and how collective action changes once the state withdraws and hands control over management to village panchayats (local governments) and other groups. The analysis of factors that influence ongoing maintenance of watershed structures indicates that collective action emerges when user groups are small and homogenous and communities are dependent on a large number of wells. Further, greater success is likely where user groups have more knowledge and control over funds available for maintenance activities after the state withdraws.     

Informal water vendors and the urban poor: evidence from a Nairobi slum

ABSTRACT

In Kenya, informal urban water markets serve the poor in areas where public utilities have failed to deliver. They often charge high prices, sell low-quality water and perform water transactions in a way that is unfair to the buyers. They still remain one of the most popular alternatives for water provision, as they can offer flexibility of supply arrangements and payment systems which are beyond the scope of large-scale water providers. In the major restructuring of Kenya’s urban water delivery system towards commercialization and privatization, these private vendors are being regularized for better service delivery in terms of regulation of prices and quality of water.     

Participatory water governance between theories and practices: learning from a community-based initiative in India

Abstract

Despite increasing convergence on the social learning concept as a theoretical foundation of collaborative practices for water governance, this article shows the pitfalls of its uncritical application as a normative ideal. The discussion is based on the analysis of a community-based initiative for water supply and slum upgrading in India, which is considered a best practice of good governance due to its collaborative approach. A different interpretation of the project is proposed through the analysis of its successes and failures from a community perspective. Finally, a recommendation for context-specific selection of theoretical bases for participatory practices is made.     

Urban water demand,climatic variation,and irrigation-water insecurity: interactive stressors and lessons for water governance from the Angat River basin (Philippines)

Climatic variation and intersectoral water competition increasingly challenge the effective provision of irrigation services. This article explores their combined effects on irrigation allocation from the Angat Reservoir (Philippines), where domestic water use in Metro Manila has overtaken regional irrigation as the dominant right-holder. Rules protecting Metro Manila’s large right to water ‘interact’ with dry spells to affect irrigation security in wet and dry seasons. Historically, irrigators were uncompensated because re-allocation’s cause was contested as (1) an unforeseeable climatic event (releasing domestic utilities of liability), or (2) produced by urban demand (requiring compensation). Trade-off rules must be prepared to navigate combinatory effects.     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.