Assessing the financial performance of water user associations: a case study at Great Menderes basin,Turkey

Management, operation and maintenance services of about 1.7 million ha irrigation areas, constructed the scheme by State Hydraulic Works (DSI) were turned over to Water User Association (WUA) in Turkey. The number of the WUAs is 330 in Turkey for 2005. There is therefore an urgent need to study methods of measurement and evaluation of financial performance of WUA in order to improve the financial performance and raise the management level of WUA. This paper proposes 12 financial indicators in order to measure and evaluate the financial performance of WUAs. Based on the results in four irrigation schemes and WUAs in Great Menderes basin, Turkey, the methods of measurement and calculation of financial performance indicators selected, and difference factor value related to each indicator are presented. Several financial performance indicators and difference factor values varied widely 1999 to 2004. Therefore, these financial performance indicators should be carefully evaluated and monitored for financial sustainability of WUAs.     

Using satellite remote sensing to assess irrigation performance in Water User Associations in the Lower Gediz Basin, Turkey

The aim of this research was to assess the irrigation performance of the Salihli Right Bank, Salihli Left Bank, Ahmetli, Gokkaya, Turgutlu, Mesir, Sarikiz, Gediz, Menemen Right Bank and Menemen Left Bank Water User Associations (WUAs) in the Lower Gediz Basin in western Turkey, using remote sensing techniques. To reach this aim the performance of the irrigation system for the 2004 irrigation season was determined according to five indicators, namely overall consumed ratio (e_p), relative water supply (RWS), depleted fraction (DF), crop water deficit (CWD) and relative evapotranspiration (RET). Potential and actual evapotranspiration parameters used in determining these indicators were estimated according to the Surface Energy Balance Algorithm for Land (SEBAL) method using NOAA-16 satellite images.Seasonal averages of these indicators ranged from 0.59 to 2.26 for e_p, 0.47-1.66 for RWS, 0.43-1.31 for DF, 180.5-269.5 mm month⁻¹ for CWD, and 0.61-0.74 for RET. According to the seasonal average values of all the performance indicators, the irrigation performance of all WUAs was usually poor. The performance indicators showed that less irrigation water was supplied to WUAs than was needed. It was concluded that proximity to the source could be an advantage in obtaining water, and that when water was insufficient, groundwater in the crop root area could be used.     

High density NOAA time series of ET in the Gediz Basin, Turkey

An evapotranspiration method comparison was carried out by the International Water Management Institute (IWMI, Sri Lanka), at two locations in the Gediz Basin, Turkey, in the period from May to September 1998. In the IWMI study a number of ground-based techniques were compared with results obtained by remote sensing methods. Recently, a search of the satellite active archive yielded over 70 high quality level 1b images from NOAA/AVHRR over the same time period. The processing of these images with the SEBAL algorithm enabled us to build up a detailed time series of sensible and latent heat fluxes for a period of 120 days. In this paper a comparison is made between the sensible and latent heat fluxes determined from the present series of NOAA-14/AVHRR images and the results obtained earlier from various other prediction methods applied during the 1998 IWMI project. Specifically, the NOAA/SEBAL results are assessed against the scintillometer and temperature fluctuation methods. The results show that the NOAA derived evapotranspiration values follow the seasonal irrigation cycle quite well and correspond closely to the Landsat derived values, although they are lower than the results obtained with the traditional crop factor and Penman–Monteith methods.     

Assessing basin irrigation and scheduling strategies for saving irrigation water and controlling salinity in the upper Yellow River Basin, China

Water saving in irrigation is a key concern in the Yellow River basin. Excessive water diversions for irrigation waste water and produce waterlogging problems during the crop season and soil salinization in low lands. Supply control and inadequate functionality of the drainage system were identified as main factors for poor water management at farm level. Their improvement condition the adoption of water saving and salinity control practices. Focusing on the farm scale, studies to assess the potential for water savings included: (a) field evaluation of current basin irrigation practices and further use of the simulation models SRFR and SIRMOD to generate alternative improvements for the surface irrigation systems and (b) the use of the ISAREG model to simulate the present and improved irrigation scheduling alternatives taking into consideration salinity control. Models were used interactively to define alternatives for the irrigation systems and scheduling that would minimize percolation and produce water savings. Foreseen improvements refer to basin inflow discharges, land leveling and irrigation scheduling that could result in water savings of 33% relative to actual demand. These improvements would also reduce percolation and maintain water table depths below 1 m thereby reducing soil salinization.     

Assessing the performance of participatory irrigation management over time: A case study from Turkey

In many countries today, irrigation systems have been transferred to the water user associations (WUAs). Accordingly, it is believed that the performance of the irrigation systems is dependent on the performance of the WUAs.In this study, the performance of participatory irrigation management (PIM) over time is assessed with regard to the Kestel WUA serving a wide area of Turkey's Aegean coast. Data relating to the WUA is obtained from both the State Hydraulic Works and WUAs’ own records. In addition, two surveys have been carried out with the members of the WUA with an 8-year interval between them. Data have been analyzed within the framework of selected irrigation performance criteria and indicators. The non-parametric Mann-Whitney U test was used to compare the perceptions of the farmers on the WUA at different survey periods. A Logit model was estimated to evaluate the relationship between the irrigation problems and the level of satisfaction from the WUA.The performance of the WUA with the indicators of utility, productivity, sustainability and financial efficiency was found to be positive; while the performance of adequacy was identified as poor. The farmers were generally satisfied of the WUA's operation, with their level of satisfaction improving over time. On the other hand, the farmers were not fully convinced that they had input with the system management. The initial design of the channel system and its maintenance were identified to be the key factors affecting user satisfaction.Overall, the Kestel WUA may be considered a successful example, thus supporting a promising future for PIM. Yet improved control and farmer education is needed for a superior performance of all indicators; and further enhanced farmer participation in management should be achieved in order to raise the level of farmer satisfaction.     

Valuing irrigation water using survey-based methods in the Tungabhadra River Basin, India

The paper discusses the challenges in using survey-based methods of economic valuation of water: choice experiments, residual value of water and water trading prices. The three different approaches to economic valuation of irrigation water are compared, all based on data from a farmer survey conducted in two irrigation command areas in the Tungabhadra sub-basin (Karnataka State, India). Prices reported by farmers for sale and purchase of an additional irrigation are of the same order as willingness to pay estimates derived from a choice experiment. Because of small number of water trades there is large variation in market-price based estimates. Financial returns to a given crop as a function of irrigation frequency show values that are both lower (for rice) and higher (for areca nut) than choice experiment estimates. Low convergent validity of different economic valuation methods of irrigation water, is in part due to the large variation in water availability and farm conditions across the watershed, but also because of methodological weaknesses. While recognizing these weaknesses, the paper shows that representative farm surveys using a combination of valuation methods can identify heterogeneity in farm conditions and preferences that may otherwise be overlooked when carrying out irrigation pricing reform.     

Temporal irrigation performance assessment in Turkey: Menemen case study

During the recent decades, there has been an increasing effort to transfer the management of irrigation schemes from government organizations to non-governmental organizations as decentralization gained momentum and as states started to devolve some of their functions to different groups in the society. Irrigation management in Turkey was also affected by these developments. Since 1993, approximately 90% of the public irrigation schemes were turned over to the locally managed farmer organizations.This study was conducted in the Menemen Irrigation Scheme, to assess the temporal variations of agricultural, water use, environmental and financial performance indicators for the pre-transfer (1984–1994) and the post-transfer (1995–2004) periods.Results showed, after 10 years of transfer, a continued improvement in irrigation performance. The most important finding of the study was a considerable increase in output per unit of land and per unit of water after turnover. Irrigation management transfer (IMT) provided a dramatic achievement in water fee collection efficiencies and more financially self-sustaining organizations. Therefore, it can be safely concluded that the transfer process created more sustainable management for irrigation.     

Performance of Locally Managed Irrigation in Turkey: Gediz Case Study

Performance indicators for locally managedirrigation systems in the Gediz Basin,Turkey, show that during the first fouryears after management transfer there wasbeen a continued improvement in irrigationperformance. While the area cropped usingsurface water has only marginally improved,yields and water productivity have shownsignificant increases. These benefits canbe attributed in part to favorable marketconditions for cotton and grapes, but alsoto a management system that values level ofservice so that farmers are not constrainedby uncertainties in water deliveries. Individual systems are managed quitedifferently within the Gediz Basin showingthat there is scope for considerablediversity in Irrigation Associationspractices without affecting the resultingperformance of systems.     

石羊河流域咸水灌溉对土壤物理性质的影响

为揭示咸水灌溉对土壤水力特性的影响机制,探求西北内陆干旱地区的合理灌溉模式,对石羊河流域中游地区开展制种玉米咸水灌溉田间试验,通过设置4种灌溉水矿化度水平(0.71,3.00,6.00,9.00 g/L),研究土壤盐分对土壤容重、孔隙度、质地和饱和导水率的影响.研究结果表明:对土壤进行咸水灌溉会引起土壤容重、孔隙度的改变,从而改变土壤饱和导水率.随着灌水次数的增多,各个处理土壤容重都越来越大,孔隙度越来越小,从而使得饱和导水率越来越小.此外咸水灌溉还会引起土壤质地的改变,特别是黏粒含量的增大,会使土壤饱和导水率减小.研究成果对咸水资源的高效利用及农业的可持续发展,具有重要的理论意义和实用价值.     

Agricultural and environmental changes after irrigation management transfer in the Develi Basin,Turkey

Develi Basin is a semi-arid basin in central Turkey where water sustains both irrigated agriculture and an internationally important wetland, the Sultan Marshes. Agricultural and environmental changes in the Develi Basin have occurred since irrigation management was transferred in 1994 from a state authority (DSI) to irrigation associations (Kovalı and Ağcaaşar IAs). In this paper we evaluate the practices of the IAs using extensive data from interviews with farmers and IA officials, as well as data from reports prepared by DSI and the IAs, using comparisons with case studies reported in the scientific literature. Irrigated areas and surface water use in the Develi Basin showed significant fluctuations from 1995 to 2003. The area allocated to high water-consuming plants increased. Maintenance activities became dependent on fee collection rates. Quality of the irrigation water did not changed significantly. Ground-water levels, flow rates from springs, and water levels in the Sultan Marshes all dropped. Overall analyses indicate that the water requirements of the Sultan Marshes have not been met, while water use for irrigation has been effective but not efficient. To reconcile agricultural and wetland water requirements, a basin-wide approach in water planning is recommended. Amounts of water to be allocated to the IAs and wetlands need to be clearly defined. DSI has to monitor canal maintenance by the IAs more closely, and IAs need to be given more responsibilities for future rehabilitation of the canals. Realistic water pricing, increased reliability of irrigation scheduling, higher on-farm irrigation efficiency, and in the long-term, modernization of the irrigation system need to be considered.     

Assessing water consumption of banana: traditional versus modelling approach

The water consumption, expressed as ‘actual evapotranspiration’ (ET_a), plays an important role in understanding the soil–water–atmosphere–plant environment. This paper highlights two different methods to assess the water consumption of banana, a traditional and modelling approach, respectively.The first method to assess ET_a was based on the water balance equation and thus included field measurements. The second method involved the simulation model soil water atmosphere plant (SWAP). The results showed that both methods led to comparative results.This study also aimed at evaluating the performance of the SWAP-model under very different circumstances as for which it has been used previously. The uncertainty about the parameters of the SWAP model remained rather high. The most important drawback of SWAP is the enormous amount of data that is required. Since these data were not always available, this resulted in a large amount of parameters to be estimated and involved in the sensitivity analyses and calibration process. The final simulation results showed several inconsistencies. It seemed that, for successful predictions, more data were needed to describe the bottom boundary condition (BBC) of the considered soil profile in greater detail, especially when there is influence of groundwater. This BBC has indeed a great impact on the simulation results. SWAP offers several ‘simplified’ approaches concerning the BBC in case no data are available. However, in all cases SWAP seemed to overestimate the moisture content.     

过滤后黄河水对滴灌系统的影响

为探明黄河水经孔径为0.05 mm(300目)过滤器过滤后进行滴灌的可能性,模拟大田滴灌研究了黄河水滴灌条件下4种滴灌带(Nf0.72,Nf1.60,Nf2.20,Dy1.38)不同位置流量变化规律,滴灌系统平均相对流量Q_r与流量变异系数C_v、系统均匀度C_u变化规律及相关关系.结果表明:黄河水对滴头的堵塞早期呈快速发育状态,不同类型引黄滴灌系统平均相对流量随灌水次数的增加呈平缓下降—快速下降—平缓下降的规律,均在相对流量75%附近快速下降;滴头流量变异系数在系统运行初期线性增大,之后平缓变化,且与系统平均相对流量具有很好的线性关系(p<0.001);当系统平均相对流量Q_r大于75%时,滴灌系统克里斯琴森均匀度系数C_u与Ln Q_r呈线性关系(R²=0.790 9),因此,引黄滴灌系统可通过系统平均相对流量Q_r来判断系统均匀度C_u,以方便及时快速了解系统堵塞状况,以便对其运行管理进行决策.     

Assessing impacts of surge-flow irrigation on water saving and productivity of cotton

To improve water saving and conservation in irrigated agriculture, a range of field evaluation experiments was carried out with various furrow irrigation treatments in cotton fields to estimate the possibilities of improving furrow irrigation performances under conditions of Central Fergana Valley, Uzbekistan. The research consisted in comparing surge and continuous-flow in long furrows and adopting alternate-furrow irrigation. The best results were achieved with surge-flow irrigation applied to alternate furrows. Field data allowed the calibration of a surface irrigation model that was used to identify alternative management issues. Results identified the need to better adjust inflow rates to soil infiltration conditions, cut-off times to the soil water deficits and improving irrigation scheduling. The best irrigation water productivity (0.61 kg m⁻³) was achieved with surge-flow on alternate furrows, which reduced irrigation water use by 44% (390 mm) and led to high application efficiency, near 85%. Results demonstrated the possibility for applying deficit irrigation in this region.     

Agricultural water productivity assessment for the Yellow River Basin

Agricultural water productivity (WP) has been recognized as an important indicator of agricultural water management. This study assesses the WP for irrigated (WPI) and rainfed (WPR) crops in the Yellow River Basin (YRB) in China. WPI and WPR are calculated for major crops (corn, wheat, rice, and soybean) using experimental, statistical and empirically estimated data. The spatial variability of WPI and WRR is analyzed with regard to water and energy factors. Results show that although irrigated corn and soybean yields are significantly higher than rainfed yields in different regions of the YRB, WPI is slightly lower than WPR for these two crops. This can be explained by the seasonal coincidence of precipitation and solar energy patterns in the YRB. However, as expected, irrigation stabilizes crop production per unit of water consumption over space. WPI and WPR vary spatially from upstream to downstream in the YRB as a result of varying climate and water supply conditions. The water factor has stronger effects on both crop yield and WP than the energy factor in the upper and middle basin, whereas energy matters more in the lower basin. Moreover, WP in terms of crop yield is compared to that in terms of agricultural GDP and the results are not consistent. This paper contributes to the WP studies by a basin context, a comparison between WPI and WPR, a comparison of WP in terms of crop yield and economic value, and insights on the water and energy factors on WP. Moreover, policy implications based on the WP analysis are provided.     

Integration of economic and hydrologic models: Exploring conjunctive irrigation water use strategies in the Volta Basin

We describe the development, calibration and preliminary application of a dynamically coupled economic–hydrologic simulation–optimization model ensemble for evaluating the conjunctive use of surface and groundwater in small reservoir-based irrigation systems characteristic of the Volta Basin, Africa. We focus on a representative small reservoir-irrigation system located in the Antakwidi catchment in Ghana. The model ensemble consists of the physical hydrology model WaSiM-ETH and an economic optimization model written in GAMS. Results include optimal water storage and allocation regimes for irrigated production, given conjunctive surface water and groundwater systems. The goal of our research, conducted within the GLOWA Volta project, is to develop a decision support system for improving the management of land and water resources in the face of potential environmental change in the Volta Basin.     

Trickle irrigation: Predominant bacteria in treated Colorado River water and biologically clogged emitters

Summary Bacterial numbers and predominant bacterial types were determined in trickle irrigation systems receiving treated Colorado River water. Fourteen bacterial genera were isolated and identified from 86 water and sediment samples collected from trickle emitter systems receiving six water treatments. The bacteria identified were common aquatic and soil microbes and the genera in order of prevalence were Pseudomonas, Flavobacterium, Vibrio, Brevibacterium, Micrococcus, and Bacillus. A greater diversity of bacterial types was found in water that was sand filtered and received no chemical treatment. Regardless of the water treatment, Pseudomonas stutzeri was the predominant bacterium followed by Flavobacterium lutescens. The data indicated that pigmented bacteria, F. lutescens and ytophaga hutchinsonii caused the yellow color of the slime deposits in biologically clogged emitters; and, their growth was presumably supported by P. stutzeri., a nonpigmented bacterium. The occurrence of Bacillus sp. was enhanced by sand and screen filtration and markedly reduced by chemical conditioning the water with either chlorine and acid or acid alone. No strictly anaerobic bacteria, such as Clostridium sp., were detected in water treated with chlorine and acid. Iron bacteria, Sphaerotilus spp., were not detected in any water or sediment samples from trickle irrigation systems.Contribution from the U.S. Department of Agriculture, Science and Education Administration, Agricultural Research     

Cumulative relative water supply: A methodology for assessing irrigation system performance

This paper discusses the usefulness and limitations of using the concept of Relative Water Supply (RWS) for evaluating the performance of irrigation systems, with special reference to systems irrigating rice. It then describes and demonstrates the use of a modification of RWS called Cumulative Relative Water Supply (CRWS), which can be used in conjunction with RWS. The advantage of CRWS is that it provides a measure of the cumulated RWS throughout a season, both in absolute terms at any given time, and in terms of the overall seasonal trend. It allows comparison of performance of an irrigation system or subsystem both to the target, and to other systems or subsystems. It can therefore be used both as an analytical tool by researchers, and as an operational tool by managers. The use of CRWS in conjunction with RWS is illustrated with examples from Sri Lanka.     

Assessment of water delivery efficiency in irrigation canals using performance indicators

Agricultural water is delivered by open irrigation canals in system of reservoirs with a widespread distribution in South Korea. Traditional irrigation management problems include water distribution systems with less capacity than the peak demand, irregular delivery rates, and low irrigation efficiency and uniformity. It is necessary to strategically compare the estimated irrigation demands with the actual water supplies for decision making in order to maintain the water supply according to the demand. Accurate measurement and monitoring of water distribution systems is essential in order to solve the problems of water efficiency and availability. Auto water level gauges installed at the head and tail sections of each irrigation canal in the Dongjin River were used to measure the discharge during irrigation periods. In this study, we introduced an approach to assess the water delivery performance indicators of the open irrigation canals, which is essential for identifying the key issues for water management improvement. The irrigation efficiencies according to the water delivery performance indicators were measured with an automatic water gauge in the irrigation canals and were calculated from the spatial and temporal distribution of the water supply for the lack of planning in water delivery. The calculated performance indicators are useful to understand the irrigator behavior and general irrigation trends. Analysis of the results yielded insights into possible improvement methods in order to develop water management policies that enable irrigation planners to improve the temporal uniformity and equity in the water distribution.     

西藏拉萨河谷灌溉供需水分析

以拉萨河下游河谷地区为研究对象,依据1989-2010年拉萨、墨竹工卡气象站气象资料和Landsat卫星遥感影像提取的主要作物(青稞、冬小麦及油菜)种植面积,计算不同典型年份研究区总灌溉需水量;结合拉萨水文站1989-2010年径流序列资料,分析区域灌溉用水的供需平衡.结果表明:拉萨河谷地区的种植模式以粮食作物为主,河谷区种植面积在1990-2010年间增长约8%,作物种植结构没有发生显著性的变化.农作物种植面积的增加引致灌溉需水量大幅度增加,2010年的灌溉需水量达到16亿m³,比1990年增长约35%,青稞为灌溉需求最大的作物.河流径流量及灌溉用水需求的季节性变化存在差异,每年4-6月灌溉供需关系较为紧张,灌溉量占径流量近10%~20%,每年12月至次年4月正值河流枯水季,尽管该期间灌溉需水量较低,但对水资源造成的压力也是不容忽视的.拉萨河谷地区水资源供需关系较为紧张.     

Economics of drip irrigation of olives in Turkey

Agricultural growers need investment and cost guidelines for drip irrigation to evaluate the economics of getting crops into production as quickly as possible and to minimise economic losses from drought during the productive life of an olive orchard. The benefits of irrigation may include; better olive survival, earlier crop production, greater yields, efficient nutrient distribution, less plant stress, reduced yield variability and improved crop quality.This research was conducted to help olive growers make decisions regarding investments in drip irrigation systems. This analysis was aimed at the farm business level to provide an economic rationale for investing in drip irrigation systems.The net present value (NPV) criterion was used to determine the discounted break-even investment results from published responses to drip irrigation systems. Growers with typical drip irrigation systems can expect investments of US$ 2244 ha⁻¹ with 1.6 ha blocks of olives. Analysis of survey findings indicate that net present value was US$ 3464 ha⁻¹ after an initial investment of US$ 2244 ha⁻¹.