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An experiment was conducted at CCS Haryana Agricultural University, Hisar during rabi 2010-11 and 2011-12, consisting of three irrigation frequencies viz. one irrigation at CRI, two irrigations at CRI and heading and four irrigations at CRI, late tillering, heading and milking in main plots and five nitrogen levels (0, 50, 100, 150 and 200 kg N/ha) in sub-plots in strip plot design with four replications. Grain yield and NUE increased significantly with increased irrigation levels. Increase irrigation frequency increased the N (33.4 and 31.3%), P (42.2 and 42.3%) and K (26.7 and 25.1%) uptake over one irrigation during 2010-11 and N (16.0 and 15.9%), P (19.4 and 20.7%) and K (11.2 and 13.5%) during 2011-12. Increased nitrogen dose increased the protein content, hectolitre weight, sedimentation value and grain yield over control. Maximum and minimum nutrient uptake was recorded with 200 and 0 kg N/ha. [ABSTRACT FROM AUTHOR]

One of the major shortcomings of the Participatory Irrigation Management/Irrigation Management Transfer (PIM/IMT) programs undertaken in many countries of the world, is the predominant absence of Monitoring & Evaluation (M&E) systems specifically addressed to accompany these processes, and become a major instrument to correct, improve and learn. To contribute to closing this gap, this paper presents the main features of 'MONEVA', an M&E system tailored to PIM/IMT programs, and adapted to different Mediterranean Countries. The system is based on the principles of the Logical Framework Analysis (LFA), which permitted the development of objectives, outcomes, outputs and appropriate indicators for the monitoring of results. MONEVA is integrated with seven menus and many submenus which detailed description is reported in the embedded User's Manual. Only selected options are presented in this paper. The important and innovative features of MONEVA are its capacity to adapt to every country by using only the indicators relevant to the country, and a simple and objective system of evaluation. The results of its application in the pilot countries Jordan and Tunisia, i) demonstrated its flexibility to adapt to local contexts and the easiness of its application which supported its adoption, and ii) validated its characteristics as a Decision Support System (DSS), having a great potential for improving the implementation of the PIM/IMT programs, through the identification of their criticalities and thus, facilitating the definition of corrective actions at government and agency levels, but particularly, at the Water Users' Association (WUA) level. [ABSTRACT FROM AUTHOR]

Behavioral experiments have demonstrated that people do cooperate in commons dilemmas. There are alternative theories that are proposed to explain the data. We will use agent-based models to compare alternative behavioral theories on a series of experimental data of irrigation games. The irrigation dilemma captures situations of asymmetric access to common resources while contributions of all participants are needed to maintain the physical infrastructure. In our model analysis we compare various alternative theories, including naïve simple ones like selfish rational actors and altruistic actors. We contrast these with various alternative behavioral models for collective action as well as inclusion of other-regarding preferences. The systematic comparison of alternative models on experimental data from 44 groups enables us to test which behavioral theories best explain the observed effects of communication. We do not find that one theory clearly outperform others in explaining the data. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article aims to propose a RFID system to detect the humidity of the soil in flowerpots and help farmers to judge whether the plants should be watered or not. By tuning the tag to dry soil state, it achieves higher dynamic range and sensitivity (20 dB) compared to a commercial RFID tag performance. This approach saves the addition of a sensor element to the RFID tag to operate as a wireless sensor. [ABSTRACT FROM AUTHOR]

Droughts and climate change in regions with profitable irrigated agriculture will impact groundwater resources with associated direct and indirect impacts. In the integrated water resource management (IWRM), managed aquifer recharge (MAR) offers efficient solutions to protect, conserve, and ensure survival of aquifers and associated ecosystems, as the Water Framework Directive requires. The purpose of this paper is to analyse the socio-economic feasibility of the MAR system in the overexploited Boquerón aquifer in Hellín (Albacete, Spain) under climate change and varying irrigation demand conditions. To assess, in monetary terms, the profitability of the MAR system, a cost-benefit analysis (CBA) has been carried out. The results for the period 2020-2050 showed that the most favourable situations would be scenarios involving artificial recharge, in which future irrigation demand remains at the present level or falls below 10% of the current irrigation surface, as these scenarios generated an internal rate of return of between 53% and 57%. Additionally, the regeneration of the habitat will take between 5 and 9 years. Thus, the IWRM with artificial recharge will guarantee the sustainability of irrigation of the agricultural lands of Hellín and will achieve water balance even in severe climate change conditions. [ABSTRACT FROM AUTHOR]

A 3-year study was conducted in the Catawba-Wateree River Basin during the spring and summer months of 2009-2011 to evaluate the water savings potential of three smart irrigation controllers compared with standard timer-based irrigation controllers. Thirty-six residential sites, 12 on each of three Duke Energy lakes (Lake Norman, Lake Hickory, and Lake Wylie), were selected for the study. A 3-year study was conducted in the Catawba-Wateree River Basin during the spring and summer months of 2009-2011 to evaluate the water savings potential of three smart irrigation controllers compared with standard timer-based irrigation controllers. Thirty-six residential sites, 12 on each of three Duke Energy lakes (Lake Norman, Lake Hickory, and Lake Wylie), were selected for the study. Each site had an automated, underground irrigation system that directly drew water from the Duke Energy lake that the property bordered. None of the systems had previously been metered and there was no charge to homeowners for withdrawing water from the bordering lake. All sites were instrumented with water meters in 2009 to monitor irrigation water withdrawals, and irrigation system audits were performed before installation of smart technologies. After collecting baseline water-use data in 2009, existing controllers were replaced with one of three smart controllers at 27 of the study sites in 2010, and irrigation was monitored through the end of the 2011 irrigation season. Irrigation treatments included a standard irrigation controller with an add-on soil moisture sensor system (SMS), an evapotranspiration (ET) based controller that received daily reference evapotranspiration estimates from a third-party provider (ET1), an evapotranspiration-based controller with an on-site weather sensor (ET2), and a comparison group that used the existing irrigation controller with no intervention (COMP). Weekly water withdrawals were monitored with on-site data loggers, and turf quality was visually rated and characterized with a normalized difference vegetation index (NDVI) meter. The SMS treatment applied the most irrigation per week (mean of 27.4 mm week-1), compared with 24.7 mm week-1 for the ET1 treatment, and the COMP and ET2 treatments that applied 20.9 and 19.9 mm week-1, respectively. Although applying the most irrigation, the SMS treatment had the greatest effect on water-use behavior for sites receiving technologies, reducing irrigation by 11.7 mm week-1 compared with the baseline year in which the SMS group applied the most water. There was no evidence of a change in water-use behavior in the COMP treatment, but collectively the smart treatments reduced irrigation from 60% more than the gross irrigation requirement (GIR) in 2009 to only 10% more than GIR in 2010 and 2011, without adversely affecting the turf quality. Visual turf quality ratings in the COMP treatment were slightly less than the minimally acceptable level, which may have resulted from underirrigation during high water demand periods. Several challenges to retrofitting existing systems and issues with smart controllers were observed, including poorly designed and maintained existing irrigation systems, incompatibility between existing controllers and SMS sensor modules, failure of all nine soil-moisture sensors, communication failures in ET-based controllers, and manual overrides of smart technologies by study participants. This study emphasizes the importance of proper installation, programming, and maintenance of smart technologies on suitable irrigation systems if they are to function correctly. To maximize water savings, smart irrigation retrofits should be targeted toward systems that historically overirrigate. [ABSTRACT FROM AUTHOR]

Performance indices can be used as indices of energy use in irrigation systems. Pumping stations (PSs) are elements that require energy for irrigation of rice fields by conventional flood irrigation. Interplay of physical, hydraulic, and electrical parameters generates indices that determine the performance in the diagnosis of PSs, operation, and projects for new sets. In this study, it was proposed and classified performance indices for PSs in rice fields, focusing on the efficient use of energy. The study was carried out through an investigation of 160 PSs in operation, located at the western border of Rio Grande do Sul, Brazil, which constituted an actual field situation. Next, PSs were optimized in relation to the selection of a piping system, using the lowest total cost, the choice of pump, and motors with better performance for the necessary situation as criteria. Results provided nine indices that classified the performance as "excellent", "very good", "good", "poor", and "very poor", which allowed the assessment of projects and the diagnosis of PSs. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a comprehensive approach for spatial and temporal demand profiling in water distribution systems. Multiple linear regression models for estimating network design parameters and decision trees for predicting daily demand patterns are presented. Proposed approach is a four-step procedure: data collection, data processing, data characterization, and spatial and temporal demand profiling. Continuous flow measurements and infrastructure and billing data were collected from a large set of water network areas and combined with census data. Main results indicate that family structures (i.e., families with elderly or adolescents), individuals' mobility (i.e., people employed in the tertiary sector and university graduates) and public consumption (i.e., public spaces' irrigation) are key-variables to profile water demand. Profiling models are of the utmost importance to describe water demand in areas with no monitoring but with similar socio-demographic characteristics to the ones analyzed, to improve network operation and to support network planning and design in new areas. Obtained models have been tested for new areas, showing good prediction performances. [ABSTRACT FROM AUTHOR]

Improving energy and hydraulic performance of large-scale pressurized irrigation is now perceived as a very pressing need, after large budgets have been allocated into systems modernization. This paper tackles this priority area by developing a management oriented multi-step methodology, that integrates different existing models, to sector the system according to the pressure requirements of the hydrants, and to regulate the pumping station for i) a fixed and a variable pressure head control, and for ii) an enhanced performance. When applied to an on-demand system in the Sinistra Ofanto irrigation scheme of Foggia (Italy), this integrated approach showed potential for energy saving under the optimal scenario of 49 %, and noticeable improvement in the system performance in terms of hydrant pressure heads, as compared to the actual conditions. The monetary assessment demonstrates that the achieved energy saving amounts to 23,636 Euros per irrigation season, 45 % among which are due to sectoring. [ABSTRACT FROM AUTHOR]

The saline groundwater irrigation is an important problem in the arid and semiarid region because it can cause soil salinization and reduce crop productivity. The accurate spatial distribution of groundwater salinity can be helpful to managers and decision makers. In this study, the mapping of salinity risk through groundwater electrical conductivity (EC) irrigation was performed based on data collected from 88 wells in the Lower-Cheliff plain (Algeria). The EC data showed a normal distribution based on elementary statistics. The EC classified using Riverside method point out a high risk of groundwater salinity (Class C3) or very high risk (Class C4) for soil salinization. The EC estimated by ordinary kriging method (OK) revealed on one hand, an underprediction of a high value, on the other hand, an overprediction of low value. The methodology of nonparametric and nonlinear of indicator kriging (IK) was performed by three thresholds: EC > 2.25, EC > 3, and EC > 5 dS=m. The map has been obtained from the combination of the local conditional cumulative distribution function (CCDF). The interpolated map by IK indicates the same overall spatial distribution of salinity with the one obtained by OK, enlightening differences in the shape and size of the area. The comparison between the groundwater EC estimated by OK and the one using IK demonstrates that IK has a better spatial prediction of salinity in terms of area and uncertainty. The groundwater salinity map was improved and accurately predicted by IK interpolation method. [ABSTRACT FROM AUTHOR]

In pressurized irrigation systems the total long-term costs can often be minimized by dividing the pipeline into segments of different diameters. To properly design such a system requires an accurate hydraulic analysis. In this study, an analytical procedure was developed to simulate the energy grade line along trickle laterals with dual pipe sizes. Appropriate equations were developed to accurately estimate several important design factors such as the total head loss (JTot), the total required head at the inlet (Ein) and the minimum pressure head along the lateral (Emin). The methodology takes into account the effect of the number of outlets along each reach of the lateral, outflow nonuniformity, friction factor variation, velocity head changes, and local losses. Friction losses were evaluated using the power form equation of the Darcy-Weisbach formula. Local losses and velocity head change were both addressed by obtaining an average along the lateral constant coefficient which is a function of the number of outlets and the outflow at the downstream end of each reach. Two power functions were also used to estimate the outflow nonuniformity along each segment of the lateral. The accuracy of the proposed method is very high in all cases examined and the results tend to accurately follow the numerical stepwise solution. Assuming a uniform outflow for the proposed method results in accurate estimations of Ein and Emin but generally not of JTot. The nonuniform outflow approach, on the other hand, calculates all three design parameters with a high degree of accuracy. [ABSTRACT FROM AUTHOR]

It has been well documented in specialized literature that, under certain circumstances, the Clément's first demand formula fails in estimating flow in water distribution networks. Through numerical examples, the authors show that the method fails when the number of hydrants supplied by a pipe is small or when the nominal flow rate of the hydrants is nonhomogeneous. In such cases, the normality hypothesis of the design flow rate random variable, an assumption needed by Clément's formula, cannot be made. An alternative method for calculating the design flow rate as a nonnormal random variable is presented. The method works very well in all analyzed examples, mainly because the normality hypothesis is not required. The paper also provides a free-software R-script using freely available software that allows applying the proposed method to user-defined cases. The script helps to understand the method's theoretical basis and can be used as a tool for checking the assumption of normality of data. Therefore, the program allows the applicability of Clément's method to be checked and provides an alternative accurate solution. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effect of different irrigation depths on the yield, water use efficiency (WUE), and yield response factor (Ky) of carrot (cv. 'Brasília') in the edaphoclimatic conditions of Baixada Fluminense, RJ, Brazil. Field trials were conducted in a Red-Yellow Argisol in the 2010-2011 period. A randomized block design was used, with 5 treatments (depths) and 4 replicates. Depths were applied by drippers with different flow rates, and the irrigation was managed by time domain reflectometry (TDR) technique. The reference (ETo) and crop (ETc) evapotranspiration depths reached 286.3 and 264.1mm in 2010, and 336.0 and 329.9mm in 2011, respectively. The root yield varied from 30.4 to 68.9t ha-1 as a response to treatments without irrigation and 100% replacement of the soil water depth, respectively. Values for WUE in the carrot crop varied from 15 to 31kg m-3 and the mean Ky value was 0.82. The mean values for Kc were obtained in the initial (0.76), intermediate (1.02), and final (0.96) stages. Carrot crop was influenced by different water depths (treatments) applied, and the highest value for WUE was obtained for 63.4% of soil water replacement. [ABSTRACT FROM AUTHOR]

Seasonal drought has become an important factor in agricultural production in humid and semi-humid areas. In this study, to mitigate the impact of seasonal drought, a new integrated mathematical model is proposed for optimal multi-crop irrigation scheduling, which is associated with conjunctive operation of reservoirs and ponds to maximize the annual returns for a reservoir-pond irrigation system. This objective is achieved via the use of two models: an operating policy model, which considers the regulatory role of ponds and optimizes reservoirs and ponds releases in one third of a month, and an allocation model, which optimizes irrigation allocations across crops by addressing water production function. The uneven distribution of ponds is also considered by dividing the irrigation district into many sub-districts. Artificial bee colony algorithm is innovatively improved by incorporating differential evolution algorithm and particle swarm optimization algorithm to solve this nonlinear, high-dimensional and complex optimization problem. The methodology is applied to the Zhanghe Irrigation Distict, which is located in Hubei Province of China, to demonstrate its applicability, and three additional models are simulated to demonstrate the validity of the integrated model. The results indicate that the integrated model can alleviate the impact of the seasonal drought and has remarkable optimization effect, especially for drought years. The average annual return calculated by the integrated model is 7.9, 7.0 and 3.1 % higher than that of the remaining three models, respectively. And in the special dry year, in which the frequency of rainfall is 95 %, the annual return calculated by the integrated model is 24.5, 21.8 and 10.1 % higher than that of the remaining three models, respectively. [ABSTRACT FROM AUTHOR]

Multi-purpose reservoir development have been always a big challenge for the management of water resources. This paper describes an integrated approach for investigating catchment hydrology in the development of a hydropower and a canal irrigation system based on model analyses. The investigation aims to adequately determine an optimal domestic and irrigation water resources allocation scheme based on an assessment of the reservoir water balance and capacity for hydropower. The soil and water assessment tool (SWAT) which characterizes basin hydrology and the water management and planning model MODSIM which provides a decision support system for water allocation optimization, were used in this study. The integrated approach was applied to Prek Te River basin in Cambodia. The water demand aspect was examined based on domestic water use, irrigation water, environmental flow, and water losses. An operational rule curve was developed for hydropower operation with respect to a power potential of 13 MW. Hydrologic modeling revealed 90 % dependable water of about 2.7 m/s during the dry season and 214.3 m/s during the wet season, indicative of a wet-season dependent reservoir for storage. Results from the 26-years simulation period also showed that diversions for domestic water and irrigation water supply were 92.3 % dependable for a 13 MW capacity hydropower development. The integrated approach was shown to be a valuable decision support tool for water resources management with the determination of an optimum policy for multi-purpose reservoir operation based on available basin water supply. [ABSTRACT FROM AUTHOR]

A simple stochastic model of meteorological droughts (meteo-droughts) is presented. All its components are analyzed and described, along with their probabilistic structures. The model is composed of ten defining descriptive parameters and each of them is a random variable. The statistical explanation of the entire probabilistic process of meteo-droughts provides the base from which the procedure of developing the m-year synthetic meteo-drought is derived. From the meteorologist's and consulting engineer's point of view this model can be used efficiently to explain meteo-drought phenomenon in a quantifiable manner. This model is an approximate, not exact theoretical method of the probabilistic meteo-drought analysis. The method is intended for practical use by various professionals, such as irrigation, agricultural and forest engineers, hydrologists and meteorologists. The method has been applied in this paper to data observed at Sombor meteorological station, Serbia. Each defined meteorological drought be it past, present or future, can be described quantitatively and completely by the presented stochastic method. In other words, each meteo-drought is given its 'identification card' (ID card). The application of the procedure has shown that the method is simple, yet complete, reliable and efficient. [ABSTRACT FROM AUTHOR]

The eco-hydrological model SWAT is used worldwide for simulating hydrology and water quality of agricultural catchments. One of the main water uses is irrigation, predominantly in arid and semi-arid regions. Climate impact simulations show that a future increase of irrigation demand can be expected for humid regions. Options for adaptation include the improvement of irrigation techniques and the modification of crop patterns. In our study we investigate the application of SWAT for the development of water saving irrigation control strategies in a humid river catchment in Northern Germany. We developed different scenarios using both soil moisture deficit control and plant water demand control. The results show plausible changes of irrigation amounts when changing the trigger points of both control methods. By deficit control strategies, the water consumption could be reduced with only a moderate decrease of crop yield. Differences between soil characteristics were well shown in the SWAT simulations, but the model consistently overestimated irrigation values. Furthermore we found a high variability of the model errors between the different years, even if the long term average values are considered acceptable. Future research is needed to improve the model accuracy in automatic irrigation control. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyl (PCB) pollution related to the use of organic waste as fertilizers in agricultural soils is a cause of major concern. In the study presented herein, PCB concentration was studied through a field trial conducted in two agricultural soils in the province of Palencia (Spain) over a 4-year period, assessing the impact of irrigation and of different types of organic waste materials. The amounts of organic waste added to the soil were calculated according to the nitrogen needs of the crop, and the concentration of PCBs was determined before and after the application of the organic waste. The resulting persistence of the total PCB content in the agricultural soils, compared with the PCB concentration in the original soils, ranged from 27% to 90%, with the lowest value corresponding to irrigated soils treated with municipal solid waste compost (MSWC) and the highest value to non-irrigated soils treated with composted sewage sludge (CSS). An estimate of the PCB content in agricultural soils after the application of organic waste materials until year 2050 was obtained, resulting in a value below 5 ng·g, considered a background value for soils in sites far away from potential pollution sources. [ABSTRACT FROM AUTHOR]

Side weirs are used to divert the flow from a main channel to a desired environmental area. These basic hydraulic elements are commonly preferred in drainage and irrigation systems of surface water. Many studies have been conducted to determine the outflow discharge of side weirs. De Marchi's approach, which assumes constant specific energy along the side weir, can be applied to describe the surface equation and therefore the discharge coefficient. However, the use of this approach is not easy in experimental and theoretical studies. This study presents a new semianalytical approach that determines the discharge capacity of rectangular side weirs. The findings of this new method are consistent with numerical and experimental results. [ABSTRACT FROM AUTHOR]

In south-west of Spain, the strawberry crop generates high economic value goods and high rate of employments. However, strawberry is cultivated in the vicinity of the Doñana National Park, a wetland with the maximum European environmental protection. Hence, minimize agricultural water use is of considerable interest in this area. Two experiments were conducted in order to determine strawberry ( Fragaria × ananassa ) irrigation requirements. The experiments were carried out with Sabrina and Antilla cultivars without deficit irrigation. Three irrigations amounts were applied with different water volumes. Drainage lysimeters were installed in order to measure crop evapotranspiration. In Sabrina trial, seasonal crop evapotranspiration ranged from 430 to 453 mm, whereas in Antilla it reached 352 mm. The crop coefficient reached maximum values of 1.1 and 0.8 in Sabrina and in Antilla , respectively. In Sabrina trial, irrigation efficiency of 81% was achieved when an irrigation volume of 5500 m 3 ha −1 was applied. In all Sabrina trial treatments, marketable fruit production exceeded 1000 g plant −1 and crop productivities were above 74 t ha −1 , with no significant differences among treatments ( P < 0.05). In Antilla trial, the maximum irrigation efficiency reached was 58%. The yield was around 750 g plant −1 , whereas land productivity was above 48 t ha −1 , with no significant differences between treatments. Water productivity was higher in Sabrina trial. The results suggest that following an irrigation schedule based on meteorological data and estimated crop coefficients, can result in significant water savings without losses in yield. [ABSTRACT FROM AUTHOR]

This paper analyzes the consequences of adopting new on-farm irrigation management strategies (low discharge rates, long irrigation times and high frequencies) in an existing on-demand and sectorized pressurized irrigation system in eastern Spain. The sectorized behavior of the network was analyzed using two criteria: (i) the operating sectors obtained in a first stage by arranging the hydrants depending on their altitude respecting the pumping station and (ii) the operating sectors obtained by means of an optimization process. The Simulated Annealing combinatorial metaheuristic optimization technique was employed to find the best solution. Random on-demand patterns were generated using a Montecarlo simulation. The hydraulic requirements of the network were analyzed in every scenario by the Epanet 2.0 engine. The effect on energy consumption, power requirements and energy costs was assessed taking into account the electricity tariff billing structure. It was found that reductions in emitter discharge ( q e ) and Energy consumption ( E ) - Energy Cost (EC) savings are not inherently related to each other. Certain amounts of E and EC could be saved when the number of sectors and operating time parameters were properly selected. Pulsed irrigation in the current scenario showed an energy saving potential of 10.67, 6.43 and 6.99% for power capacity, E and EC , respectively. [ABSTRACT FROM AUTHOR]

The present study was carried out in order to evaluate the effects of irrigation depths applied through drip and presence/ absence of soil cover in onion yield, under agroecological farming. The experiment was conducted in Seropédica, RJ, Brazil, from May to September 2012. The experimental design was a randomized complete block with split-plot design with 10 treatments and 7 replications, characterized by the presence (+S) and absence (-S) of soil cover and five irrigation depths according to percentages of the crop evapotranspiration (ETc): 0, 22, 45, 75 and 100% (0, 155, 220.6, 320.5 and 372,7mm in +S condition and 0, 145.5, 207.6, 285, 351,4mm in -S condition). The irrigation influenced by second-order polynomial regression the total yield of bulbs, percentage distribution of bulbs in diameter classes and water use efficiency (WUE) in the -S condition, and in the linear regression the WUE in +S condition. The soil cover promoted an increase on the total bulb yield, WUE and the percentage of bulbs classified in classes of greater diameter. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to develop an easy-to-use weather generator (WG) for the downscaling of gridded data to point measurements at regional scale. The WG is applied to daily averaged temperatures and annual growing degree days (GDD) of wheat. This particular choice of variables is motivated by future investigations on temperature impacts as the most important climate variable for wheat cultivation under irrigation in Iran. The proposed statistical downscaling relates large-scale ERA-40 reanalysis to local daily temperature and annual GDD. Long-term local observations in Iran are used at 16 synoptic stations from 1961 to 2001, which is the common period with ERA-40 data. We perform downscaling using two approaches: the first is a linear regression model that uses the ERA-40 fingerprints (FP) defined by the squared correlation with local variability, and the second employs a linear multiple regression (MR) analysis to relate the large-scale information at the neighboring grid points to the station data. Extending the usual downscaling, we implement a WG providing uncertainty information and realizations of the local temperatures and GDD by adding a Gaussian random noise. ERA-40 reanalysis well represents the local daily temperature as well as the annual GDD variability. For 2-m temperature, the FPs are more localized during the warm compared with the cold season. While MR is slightly superior for daily temperature time series, FP seems to perform best for annual GDD. We further assess the quality of the WGs applying probabilistic verification scores like the continuous ranked probability score (CRPS) and the respective skill score. They clearly demonstrate the superiority of WGs compared with a deterministic downscaling. [ABSTRACT FROM AUTHOR]

Based on the data series of rainfall, reference crop evapotranspiration and irrigation water from 1970 to 2013 in the Luhun irrigation district of China, the multivariate joint probability of water supply and demand are constructed with student t-copula function. The results show that student t-copula function can indicate the associated dependence structure amongst these variables well, and the constructed multivariate copula-based joint probability distribution reveal the statistical characteristics and occurrence probability of different combinations of water supply and water demand. Moreover, the trivariate joint probability distribution is more reasonable than the bivariate distribution to reflect the water shortage risk, and these joint distribution values of different combinations of water supply and demand can provide the technological support for water shortage risk evaluation in the irrigation district. [ABSTRACT FROM AUTHOR]

This research investigated the optimum on-farm water management methods for a summer crop (Maize). Water equity and productivity were optimized simultaneously by using genetic algorithms in Doroodzan Irrigation Network. Increase in water reduction fraction (WRF) (0.0 to 0.8) has the incremental effect on water equity (on average 19.4 %), however by increasing WRF, water productivity initially increased (on average 25.3 % at WRF = 0.4) and then decreased. With increasing irrigation application efficiency (E) (40 to 90 %), the values of water equity and productivity increased by on average 52.8 and 91.5 %, respectively. Increment of conveyance efficiency of channels (E) (70 to 90 %) resulted in minimum incremental effect on water equity and productivity (on average 18.5 and 11.9 %, respectively). Furthermore, the values of performance measure decreased from wet water year to drought water year. Tape irrigation system was considered as the best choice at low quantities of WRF (<=0.4), however for higher values of WRF (> = 0.6), sprinkler irrigation system was considered as the best choice for achieving higher values of water equity and productivity. Meanwhile, when equity and productivity were considered together for a specific method of deficit irrigation scheduling, under specified quantity of irrigation water, with increasing equity the water productivity reduction was negligible. [ABSTRACT FROM AUTHOR]

The present work aims at assessing the impact of MSW on the groundwater quality around dumping yard site, located near the Sangamner city by water quality index (WQI) and its integration in geographical information system (GIS). Groundwater samples ( n = 15) around the dumping yard were collected using Garmin GPS device in October 2013 and October 2014. Physico-chemical analysis of same samples was carried out for pH, EC, TDS, Na, K,Ca, Mg, TH, Cl, HCO, SO and NO along with the heavy metals like Fe, Zn, Cd and Cr by using standard methods. Similarly, SAR, KRs, RSC and SSP were also calculated to know the groundwater quality into irrigation perspective. WQI for 15 samples were calculated using physico-chemical results/data of 12 parameters and its desirable limit of BIS standard. Generated WQI ( z) for October 2013 and October 2014 were integrated with latitude ( y) and longitude ( x) values, collected using GPS during the field work. Integrated xyz data were then interpolated in Surfer-10 GIS software using inverse distance weight (IDW) method to estimate the groundwater quality of the study area. Study revealed that the groundwater quality around the dumping yard area does not confirm to drinking and domestic purposes as per the WQI and BIS standard. However, the groundwater quality is marginally suitable for irrigation as per SAR, KRs, RSC and SSP. The influence of leachate from MSW dumping site to surrounding groundwater is creating a serious concern and susceptible to potential health hazards. Thus, continuous monitoring of groundwater is desperately required in order to minimize the groundwater pollution for control the pollution-caused MSW. [ABSTRACT FROM AUTHOR]

Historic results of perennial ryegrass ( Lolium perenne L.) breeding include improved disease resistance, biomass, and nutritional quality. Yet, lack of tolerance to water stress limits its wide use. Recent efforts to increase water soluble carbohydrate (WSC) content in perennial ryegrass may increase drought tolerance. Herein, we report results of a multi-year and location evaluation of differing precipitation/irrigations levels on genetic and genotype × environment interaction effects of various agronomic traits in perennial ryegrass. The study included two UK environments (Aberystwyth, Wales and Edinburgh, Scotland) and four USA environments located in Logan, UT and consisting in four supplemental irrigation levels in a line-source irrigation design. Data included herbage dry matter, dry matter digestibility, crude protein, and WSC, collected from 2011 to 2013. There were differences ( P < 0.05) among the included cultivars for each phenotype when evaluated across environments. There was observed cultivar × environment interaction for each phenotype, which precluded the identification of the best cultivar over all environments. Additive main effect and multiplicative interaction modeling allowed for grouping of the individual environments to mega-environments. The analysis identified three mega-environments for each phenotype: (1) the UK environments, (2) the two highest Logan irrigation levels, and (3) the two lowest Logan irrigation levels. Mega-environments designations corresponded to water stress, temperature, and inherent geographic/climate differences between the environments. The evidence for the potential of increased WSC to improve drought tolerance under water stress was inconclusive, but high WSC cultivars also exhibited high herbage production under the imposed water stress. [ABSTRACT FROM AUTHOR]

Levels of Mo, As, Se, Fe, Cu, Zn, Ni, and Pb were determined in a vegetable commonly consumed in Pakistan. Samples were collected from three different sites (Ratokala, Phularwan, and Mailowal) supplied with three different water sources. Mo and Pb in water and Mo and As inC. sativumwere higher than the suggested standards at the international level. Lower bioconcentration factor and pollution load index were seen at Site-I than at other sites. A positive association was found between the rhizosphere metals and those of the vegetable at all three sites. Enrichment factor at three sites ranged from 0.28 to 10.39. The highest value of daily intake of metals was found for Fe (0.245 mg/kg/day) and of the health risk index for As (70.41) at the wastewater inundated site. It is inferred that uptake of Mo, As, Cu, Ni, and Pb throughC.sativumrepresents a high health danger to the individuals using this vegetable. [ABSTRACT FROM PUBLISHER]

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Purpose: Salinisation is a threat not only to arable land but also to freshwater resources. Nevertheless, salinisation impacts have been rarely and only partially included in life cycle assessment (LCA) so far. The objectives of this review paper were to give a comprehensive overview of salinisation mechanisms due to human interventions, analyse the completeness, relevance and scientific robustness of existing published methods addressing salinisation in LCA and provide recommendations towards a comprehensive integration of salinisation within the impact modelling frameworks in LCA. Methods: First, with the support of salinisation experts and related literature, we highlighted multiple causes of soil and water salinisation and presented induced effects on human health, ecosystems and resources. Second, existing life cycle impact assessment (LCIA) methods addressing salinisation were analysed against the International Reference Life Cycle Data System analysis grid of the European Commission. Third, adopting a holistic approach, the modelling options for salinisation impacts were analysed in agreement with up-to-date LCIA frameworks and models. Results and discussion: We proposed a categorisation of salinisation processes in four main types based on salinisation determinism: land use change, irrigation, brine disposal and overuse of a water body. For each salinisation type, key human management and biophysical factors involved were identified. Although the existing methods addressing salinisation in LCA are important and relevant contributions, they are often incomplete with regards to both the salinisation pathways they address and their geographical validity. Thus, there is a lack of a consistent framework for salinisation impact assessment in LCA. In analysing existing LCIA models, we discussed the inventory and impact assessment boundary options. The land use/land use change framework represents a good basis for the integration of salinisation impacts due to a land use change but should be completed to account for off-site impacts. Conversely, the land use/land use change framework is not appropriate to model salinisation due to irrigation, overuse of a water body and brine disposal. For all salinisation pathways, a bottom-up approach describing the environmental mechanisms (fate, exposure and effect) is recommended rather than an empirical or top-down approach because (i) salts and water are mobile and theirs effects are interconnected; (ii) water and soil characteristics vary greatly spatially; (iii) this approach allows the evaluation of both on- and off-site impacts and (iv) it is the best way to discriminate systems and support a reliable eco-design. Conclusions: This paper highlights the importance of including salinisation impacts in LCA. Much research effort is still required to include salinisation impacts in a global, consistent and operational manner in LCA, and this paper provides the basis for future methodological developments. [ABSTRACT FROM AUTHOR]

Spatial surface soil moisture can be an important indicator of crop conditions on farmland, but its continuous estimation remains challenging due to coarse spatial and temporal resolution of existing remotely-sensed products. Furthermore, while preceding research on soil moisture using remote sensing (surface energy balance, weather parameters, and vegetation indices) has demonstrated a relationship between these factors and soil moisture, practical continuous spatial quantification of the latter is still unavailable for use in water and agricultural management. In this study, a methodology is presented to estimate volumetric surface soil moisture by statistical selection from potential predictors that include vegetation indices and energy balance products derived from satellite (Landsat) imagery and weather data as identified in scientific literature. This methodology employs a statistical learning machine called a Relevance Vector Machine (RVM) to identify and relate the potential predictors to soil moisture by means of stratified cross-validation and forward variable selection. Surface soil moisture measurements from irrigated agricultural fields in Central Utah in the 2012 irrigation season were used, along with weather data, Landsat vegetation indices, and energy balance products. The methodology, data collection, processing, and estimation accuracy are presented and discussed. [ABSTRACT FROM AUTHOR]

Wadi aquifers in Saudi Arabia historically have been recharged primarily by channel loss (infiltration) during floods. Historically, seasonal groundwater levels fluctuated from land surface to about 3 m below the surface. Agricultural irrigation pumping has lowered the water table up to 35 m below the surface. The geology surrounding the fluvial system at Wadi Qidayd consists of pelitic Precambrian rocks that contribute sediments ranging in size from mud to boulders to the alluvium. Sediments within the wadi channel consist of fining upward, downstream-dipping beds, causing channel floodwaters to pass through several sediment sequences, including several mud layers, before it can reach the water table. Investigation of the wadi aquifer using field observation, geological characterization, water-level monitoring, geophysical profiles, and a hypothetical model suggests a critical water level has been reached that affects the recharge of the aquifer. The wetted front can no longer reach the water table due to the water uptake in the wetting process, downstream deflection by the clay layers, and re-emergence of water at the surface with subsequent direct and diffusive evaporative loss, and likely uptake by deep-rooted acacia trees. In many areas of the wadi system, recharge can now occur only along the channel perimeter via fractured rocks that are in direct horizontal hydraulic connection to the permeable beds above and below the water table. [ABSTRACT FROM AUTHOR]

Chlorophyll is a natural coloring extract used extensively in the food and pharmaceutical industries. In Europe, most chlorophyll is produced commercially from rainfed grassland production in eastern England. This paper describes a biogeochemical modeling study to assess the potential yield benefits associated with switching from rainfed to irrigated production. The research is in response the impacts of recent summer droughts on yield coupled with risks regarding climate change, rainfall reliability and long-term viability of rainfed production. The Denitrification-Decomposition model was calibrated and validated using multiple field data ( n = 47) from 2000 to 2009 for a tall fescue grass ( Festuca arundinacea) to simulate a range of irrigation and fertilizer management regimes on yield (annual and individual yield per cut). For chlorophyll production, a schedule combining 300 mm year−1 irrigation with 300 kg N ha−1 was shown to provide the highest average yield (an uplift of +62% above current levels). Switching from rainfed to irrigated production could also potentially halve (54%) current levels of fertilizer application. The implications for reducing environmental impacts from nitrate leaching are discussed. [ABSTRACT FROM AUTHOR]

The indigenous forage species such as Buffel grass ( Cenchrus ciliaris) are capable of surviving with less water than most introduced species such as Rhodes grass ( Chloris gayana) and alfalfa. However, the productivity of Buffel grass as a function of the amount of water applied is unknown. A case study was conducted in Oman to evaluate the response of Buffel and Rhodes grasses to different irrigation levels using line-source sprinkler irrigation system. Four irrigation treatments (40, 65, 100 and 125%) based on reference evapotranspiration (ETo) with two grass species (Buffel and Rhodes grasses) were investigated as sub-main treatments in strip plot design with four replications. The average total amount of applied water during the study period were 15 126, 24 580, 37 815 and 47 269 m3 ha−1, for the four irrigation treatments, respectively. The results of 12 cuts during 514 days indicated that Buffel grass has significantly higher dry weight production (DW) and water productivity than Rhodes grass at all irrigation levels. Irrigation by 65% of ETo for Buffel grass has the highest water productivity value reached to 0.95 kg m−3 and 42% of applied water can be saved to produce the same amount of DW of Rhodes grass. Soil salinity increased in the soil profile for 40, 65 and 100% ETo irrigation levels during the summer season and the soil salinity values were higher at Rhodes than Buffel grasses location for these irrigation levels. [ABSTRACT FROM AUTHOR]

Air is squeezed out of the soil in the process of traditional irrigation. Hypoxia stress of the root zone is harmful to the yield and quality of crops. It was found that the improvement of the soil oxygen condition can increase the crop yield and quality in the root zone. In recent years, a number of studies showed that hypoxia stress has bad influence on root zone, and the ventilation technologies have some positive effects on crop yield and quality. This paper introduces and analyzes the mechanism of hypoxia stress in root zone, and provides an overview about characteristics and application on airjection irrigation. Simultaneously, the advantages and disadvantages of different airjection irrigation technologies were investigated, the achievements that have been made in this filed were summarized, and some existed problems were discussed. Based on the previous studies, the research trends of the airjection irrigation technology were proposed, which can provide a reference for the further research in the research field. [ABSTRACT FROM AUTHOR]

The purpose of this study was to apply an innovative model of expansion to irrigation management and development in fruit exporting regions in central Chile. The model showed how external influences (globalization, climate, mountains) and complex adaptive systems (water conflicts, institutions and markets) influenced the evolution of irrigation development (the extension and emergence of novel properties) towards constructive (planned irrigation development) and destructive (climate change) futures. The model was simple, geometrical, consistent and future oriented. It was an innovative representation of expanding irrigation development and valuable to entrepreneurial water developers because it described the macro-scale processes involved in irrigation development. [ABSTRACT FROM PUBLISHER]

While in the international literature water sharing in the Syr Darya Basin per past agreements is widely portrayed as most benefiting Uzbekistan, here the dynamics of water allocation within small transboundary tributaries in Ferghana Province show Uzbekistan as benefiting least. The case study highlights that water allocation for Uzbekistan within the tributaries has decreased over the years. Uzbekistan's approach to compensate for the reduced allocations by means of other water sources has had large long-term cost implications for irrigated agriculture as well as the irrigation bureaucracy. This article contributes to the international debate on benefit sharing in transboundary rivers. The article highlights that costs should be incorporated into the benefit-sharing approach, and therefore the focus on benefit sharing alone is misguiding riparian states. Furthermore, the article raises the need to reevaluate benefits, since perceptions of potential benefits change over time. [ABSTRACT FROM PUBLISHER]

Farmers in Pakistan either rely only on groundwater or manage conjunctive use of surface and groundwater for irrigating crops due to shortage of canal water. Present study was undertaken to find variations in conjunctive water management practices, groundwater productivity and crop profitability in Chuharkana irrigation sub-division in Punjab. Physical and questionnaire based data were collected from 120 farmers using stratified random sampling technique from vicinity of four watercourses of Lagar distributary. Trajectory method was employed to measure tubewells' discharge for evaluating groundwater productivity across watercourse reaches. EC, SAR and RSC were measured to evaluate groundwater quality. Results show prevalence of surface and groundwater use for irrigation. Area under conjunctive use decreased from 76.6% at head to 46% at tail due to decreased canal water supply towards tail while area irrigated by groundwater-only increased from 20% to 54% across head to tail. Analysis of groundwater samples showed lower quality levels. EC, SAR and RSC ranged between 1.27-1.55 dS m-1, 6.39-9.54 (mmol L-1)1/2 and 3.75-4.18 meL-1 respectively, with higher values towards tail. Groundwater productivity for wheat was relatively higher at the head, while that of rice did not vary much across watercourse reaches. Conducive soil conditions and more reliance on groundwater for timely irrigation resulted gross margins at the tail. [ABSTRACT FROM AUTHOR]

Agriculture of arid and semi-arid regions is effected by over extraction of groundwater (GW) around the world especially in the developing countries like Pakistan. Groundwater (GW) should be properly recharged to overcome the issue of declining water levels. Analysis of GW use against recharge is done to address the issues of sustainable management and aquifer mining in Hakra branch canal system off-taking Eastern Sadiqia canal of Pakistan. Various water balance components were computed to estimate the net recharge using modeling as well as with remote sensing techniques. Soil profile data, water table depths, canals off take discharges and all the climatic data for the year 2006-11 were used as input data sets in Soil and Water Assessment Tool (SWAT) to compute GW recharge. Hakra branch canal system is divided into 17 off-taking distributaries and direct water courses. The SWAT model is calibrated and validated using in situ extents of soil, vegetation, evapotranspiration and surface supplies. Nash-Sutcliffe Efficiency (NSE) and coefficient of determination (R²) were used as statistical parameters for calibration and validation of results. Using the net recharge, net GW abstraction was calculated for entire command area of Hakra branch canal system. SWAT was calibrated (NSE = 0.97, R² = 0.87) for the period of 2006-08 and validated (NSE = 0.98, R² = 0.90) for the period 2009-11. Average net recharge to the GW aquifer for the whole command area is estimated at -91 mm yr-1, indicating abstraction is greater than recharge from all sources. Whereas, average net GW abstraction is calculated as 712 mm yr-1 in the study area. The GW abstraction trend is increasing in the tail distributaries due to less canal water supplies. It is recommended to increase the head discharge of the main canal and share of the tail distributaries. [ABSTRACT FROM AUTHOR]

Pakistan is facing a shortage of water for many years, mainly due to increase in population and mismanagement of available water resources. There is average annual potential of 23 billion m³ in hill torrent water resources of the country, which has not yet been utilized to its productive potential. This study compared the irrigation practices, crop yield, water productivity and benefit cost ratio of spate irrigated crops with other available sources of irrigation in Mithawan hill torrent command area of Dera Ghazi Khan, Pakistan. The data were collected through field visits/observations, farmers' interviews, and from the relevant organizations. CROPWAT model was used to determine crops water requirements for assessment of irrigation efficiencies while SPSS software was used for descriptive statistics of the study data. The cropping intensities in the study area during wet and dry years were 90 and 70%, respectively, with an average of 80%. The spate irrigated fields were applied 1.05m depth of water at once in a season that had an average application efficiency of 28% whereas, the efficiency of canal water and groundwater applied separately or conjunctively varied from 24 to 86% with an average of 52%. The water productivity of spate irrigated crops varied from 0.08 to 0.19kg/m³ while canal water and/or groundwater irrigated crops cultivated in the study area varied from 0.27 to 3.28kg/m³. Normally, cotton was cultivated with canal water and onion with groundwater that had water productivity of 0.27 and 3.28kg/m³, respectively. The benefit cost ratio of spate irrigated crops varied from 1.49 to 2.39, while for irrigated with canal water and/or groundwater it varied from 1.29 to 1.57. Based on the result of this study, it may be concluded that the efficient utilization of hill torrents for spate irrigation would improve the copping intensities, crop yield, water productivity and socioeconomic conditions of the farmers of study area. Also, the efficient utilization of hill torrent water for spate irrigation would minimize the dependence on canal water and groundwater in the study area. [ABSTRACT FROM AUTHOR]

Many bryophytes are intolerant of osmotic stresses; nevertheless, Bryum argenteum often spreads in golf course greens irrigated with water containing a moderate amount of sodium and/or bicarbonates. The ability of B. argenteum to survive in this stressful environment could be linked to the use of acid injection systems, which are often retrofitted to irrigation systems to combat the negative effects of these harmful salts. The objective of this study was to determine if altering the pH of sodic irrigation water using either sulfuric or hydrochloric acid affects the growth of B. argenteum. Secondarily, if growth of B. argenteum was affected, we sought to understand whether that effect was due to differences in nutrient uptake or availability under the different water pHs and/or acidifying sources. Phosphate buffer solutions (0.01 M, pH = 9) were titrated with each acid to obtain pHs 5, 6, 7 and 8. Irrigation solutions were applied daily to pots containing a sand substrate and nascent B. argenteum for 28 d. Acid source had no effect on moss cover, but pH significantly affected B. argenteum cover. Generally, pots irrigated with pHs 5 and 6 had six- to seven-fold increases in B. argenteum cover compared to pHs 7 and 8. Additionally, the shoot tissue of pots treated with pH 5 contained twice as much potassium compared to pots irrigated with pH 9. These results indicate the growth of B. argenteum increases when acid injection systems are used to amend sodic irrigation water. [ABSTRACT FROM AUTHOR]

Small, stable, and homogeneous user groups are expected to achieve better outcomes within common-property resource regimes. Empirical identification of these effects, however, remains difficult because user group characteristics are unlikely random across systems and data of communally managed resources are hard to come by, exposing analyses to omitted variable bias. To address this issue, I collect a panel data set of 50 communal irrigation systems in New Mexico. With annual observations from 1984 to 2011, I test for the impact of group size, new users, and group heterogeneity using fixed effects, controlling for a number of timeinvariant factors that would otherwise be omitted. I find robust results demonstrating that larger user groups experience worse outcomes. However, if I forgo the fixed effects and mimic cross-sectional analysis, I identify a result smaller in magnitude and statistical significance, suggesting that omitted variable bias can account for some of the weak evidence in the existing literature. [ABSTRACT FROM AUTHOR]

Geographical Information System (GIS) has been used in this paper to delineate groundwater resources potential in the western part of greater Kushtia district of Bangladesh, where urgent attention for augmentation of irrigation water supply is required. Thematic maps of transmissivity, hydraulic conductivity, specific yield, net recharge, aquifer thickness, surface water bodies, aquifer resistivity, overburden aquitard thickness and its resistivity have been prepared and assigned weight according to their relative importance using Analytical Hierarchical Process for the preparation of groundwater potential model. Since the values within each thematic map vary significantly, they are classified into various ranges or types and assigned ratings. Finally, the thematic maps are integrated using GIS to prepare the groundwater potential map for the study area in terms of Ground Water Potential Index (GWPI). The evolved map indicates that 22.51% of the study area have GWPI more than 0.70 and therefore, have excellent prospective for exploitation. About 69.12% of the area with GWPI ranging from 0.50 to 0.70 is also quite promising for groundwater abstraction, while the rest 8.37% area having GWPI below 0.50 indicates moderate potential. The obtained map of groundwater potential is found in good agreement with the yields of available pumping test data. [ABSTRACT FROM AUTHOR]