Total Net Benefit Research Articles

A fractional-factorial probabilistic-possibilistic optimization framework for planning water resources management systems with multi-level parametric interactions

In this study, a multi-level factorial-vertex fuzzy-stochastic programming (MFFP) approach is developed for optimization of water resources systems under probabilistic and possibilistic uncertainties. MFFP is capable of tackling fuzzy parameters at various combinations of α-cut levels, reflecting distinct attitudes of decision makers towards fuzzy parameters in the fuzzy discretization process based on the α-cut concept. The potential interactions among fuzzy parameters can be explored through a multi-level factorial analysis. A water resources management problem with fuzzy and random features is used to demonstrate the applicability of the proposed methodology. The results indicate that useful solutions can be obtained for the optimal allocation of water resources under fuzziness and randomness. They can help decision makers to identify desired water allocation schemes with maximized total net benefits. A variety of decision alternatives can also be generated under different scenarios of water management policies. The findings from the factorial experiment reveal the interactions among design factors (fuzzy parameters) and their curvature effects on the total net benefit, which are helpful in uncovering the valuable information hidden beneath the parameter interactions affecting system performance. A comparison between MFFP and the vertex method is also conducted to demonstrate the merits of the proposed methodology.

Simultaneous optimization of fuel surcharges and transit service runs in a multimodal transport network: a time-dependent activity-based approach

This paper addresses the simultaneous optimization problem of fuel surcharges and transit service runs for energy sustainability of multimodal transport network using a time-dependent activity-based approach. To model commuters' choices of trip chain, travel mode, departure time, route, and activity timing and duration over the times of a day, a time-dependent activity and multimodal travel choice equilibrium problem is first addressed and formulated as an equivalent variational inequality (VI) problem. A new model for optimizing the fuel surcharges and transit vehicle runs is proposed to maximize the total social net benefit of the multimodal transport system. The proposed model explicitly considers the interaction between the fuel surcharges and transit service runs and the commuters' activity–travel scheduling behavior. A heuristic solution algorithm is then developed to solve the proposed model. Finally, an illustrative example is given to show the application of the proposed model with various sensitivity tests. Insightful findings are presented with particularly the effects of the fuel surcharges and transit service improvement on the performance of the multimodal transport system in terms of the modal split, fuel consumption, and total social net benefit.

Optimal bus fleet management strategy for emissions reduction

Transportation is a major cause for environmental degradation via exhaust emissions. For many transit-oriented metropolitan areas, bus trips often constitute a sizeable mode share. Managing the bus fleet, in particular updating buses to comply with the newer emissions standards, therefore, can have a substantial impact on transportation-induced air quality. This paper presents the approach of remaining life additional benefit–cost (RLABC) analysis for maximising the total net benefit by either early-retiring or retrofitting the current bus fleet within their lifespans. By referring to the net benefits for different bus types estimated by RLABC analysis, the most beneficial management scheme for the current bus fleet can be identified. Optimal bus fleet management (BFM) models based on the RLABC analysis for the operator and the government are developed. Then a government subsidy plan is produced to achieve win–win solutions, which will offer efficient and flexible management schemes. To illustrate the approach, the largest bus company in Hong Kong, which carries more than 23% of the total trips in Hong Kong, is taken as a case study example. Instead of adopting a fixed retirement plan, such as replacing buses at the age of 17 as is currently practised, the proposed method develops an optimal BFM scheme that progressively phases out buses or retrofits them. This study produces promising results to demonstrate the large benefit of this approach for optimal bus fleet management.

Modelling the potential benefits of different strategies to control infection with Trypanosoma evansi in camels in Somaliland.

Trypanosoma evansi (T. evansi), the protozoan parasitic cause of camel trypanosomosis (Surra), constitutes one of the major veterinary problems worldwide. An infectious disease model of camel trypanosomosis (Surra) was adopted from one developed for buffalo and applied to study the impact of T. evansi infection on camel production. The model contained deterministic and stochastic components and the seroprevalence based on a survey conducted in Somaliland in 2011 and 2012 to simulate and estimate the economic benefits of four different control options against T. evansi infection in camels (1, 2, 3 and 4 regimens). The mean benefit per animal of controlling surra was calculated at US$354 (the treatment of all camels biannually), US$426 (the monthly targeted treatment of clinically sick camels) and US$287 (biannual targeted treatment of seropositive camels), respectively, compared with US$137 for untreated camels. Consequently, the model predicted that the total net benefit loss to a camel herd or village that was not applying the recommended effective surra control strategy was US$115,605 (69.4 billion shilling per annum).

Distributional consequences of upstream tree plantations on downstream water users in a Public–Private Benefit Framework

We apply a Public–Private Benefit Framework (PPBF) for new perspectives on the distributional consequences of land-use change in upstream watersheds (wide expansion of tree plantations) negatively affecting downstream water users. Our study area is the Macquarie River catchment in central-west New South Wales, as part of Australia's Murray–Darling Basin, where active water entitlement markets exist downstream.We consider benefits and costs to private upstream landholders allowed to establish new plantations without regard to reduced water flows and qualities to downstream users (urban, agricultural and environmental).Second, we explore a policy requiring new plantations to purchase permanent entitlements in advance for amounts of water they will divert from downstream uses; the calculated increase in evapotranspiration above that of current land-use.With no requirement to purchase entitlements, new plantation areas and their increased water consumption would be greatest, as would negative impacts on downstream water users.Some downstream water users are assumed willing to surrender entitlements at lower prices than others, resulting in an upward-sloping supply curve. Demand for entitlements by new upstream plantations will be functions of anticipated tree product yields, prices, establishment and opportunity costs. Their aggregate demand is downward sloping and intersects the supply curve to define the equilibrium quantity and price of water entitlements traded.With a tree product price of $70/m3 the economic consequences of unrestricted expansion of planting in the upper watersheds could be in the order of $639M (tree-NPV, 7%) in upstream private net benefit gains, but $388M in uncompensated losses to downstream public net benefits, counting losses of 154GL in environmental flows valued at $1M/GL, for total catchment net benefits of $251M.The policy as confirmed by our PPBF, indicates “flexible negative incentives” to reduce the expansion of new private plantations by compensating downstream public losses through sale of water entitlements from the latter to the former. Assuming that environmental flows are protected and purchase of downstream water entitlements is required from irrigators and stock and domestic users for new tree plantations, net private benefits of $192M to new plantations are added to $138M in downstream public benefits, improving the net change in catchment benefits to $330M. The policy would improve total net catchment benefit from $251M to $330M, achieving an economically efficient, socially equitable and environmentally sustainable solution, which adjusts automatically over time through the market.

Comparing the costs and benefits of floating rice-based and intensive rice-based farming systems in the Mekong Delta

This paper compares financial costs and benefits of floating rice-based and intensive rice farming systems using data from focus group discussions and household survey in four locations in the Mekong Delta. We argue that the net financial benefit per 1000m2 of integrated floating rice-based farming systems is greater than the net financial benefit of intensive rice farming system. The total net benefit of floating rice-leeks shows the highest net benefit (VND 24.8 mil./1000 m2), followed by floating rice-sweet corn- two baby corn crops and cattle systems (VND 18.5 mil./1000m2), and floating rice-chili (VND 16.7-17.7 mil./1000m2). If farmers cultivate monoculture of rice either two or three crops, the net benefits are ranging from VND 2.2-4.8 mil./1000m2 respectively. Alternatively, farmers integrate vegetables; the net benefit was ranging from VND 5.6 to 11.7 mil./1000m2. The net benefit of the two rice crops is lowest (VND 1.3-2.3 mil./1000m2). Surprisingly, if farmers convert from two intensive rice crops to two maize crops, the net benefit can reach to VND 21 million/1000m2. The results support the argument that the floating rice based systems allows farmers diversified into profitable upland crops, which can help farmers to improve their total income.?

Water resources management under uncertainty: factorial multi-stage stochastic program with chance constraints

Due to rapid growth of population and development of economy, water resources allocation problems have aroused wide concern. Therefore, optimization of water resources systems is complex and uncertain, which is a severe challenge faced by water managers. In this paper, a factorial multi-stage stochastic programming with chance constraints approach is developed to deal with the issues of water-resources allocation under uncertainty and risk as well as their interactions. It can deal with uncertainties described as both interval numbers and probability distributions, and can also support the risk assessment within a multistage context. The solutions associated with different risk levels of constraint violation can be obtained, which can help characterize the relationship between the economic objective and the system risk. The inherent interactions between factors at different levels and their effects on total net benefits can be revealed through the analysis of multi-parameter interactions.

Water quality management in a wetland system using an inexact left-hand-side chance-constrained fuzzy multi-objective approach

Water quality management is a significant item in the sustainable development of wetland system, since the environmental influences from the economic development are becoming more and more obvious. In this study, an inexact left-hand-side chance-constrained fuzzy multi-objective programming (ILCFMOP) approach was proposed and applied to water quality management in a wetland system to analyze the tradeoffs among multiple objectives of total net benefit, water quality, water resource utilization and water treatment cost. The ILCFMOP integrates interval programming, left-hand-side chance-constrained programming, and fuzzy multi-objective programming within an optimization framework. It can both handle multiple objectives and quantify multiple uncertainties, including fuzziness (aspiration level of objectives), randomness (pollutant release limitation), and interval parameters (e.g. water resources, and wastewater treatment costs). A representative water pollution control case study in a wetland system is employed for demonstration. The optimal schemes were analyzed under scenarios at different probabilities (p i , denotes the admissible probability of violating the constraint i). The optimal solutions indicated that, most of the objectives would decrease with increasing probability levels from scenarios 1 to 3, since a higher constraint satisfaction probability would lead to stricter decision scopes. This study is the first application of the ILCFMOP model to water quality management in a wetland system, which indicates that it is applicable to other environmental problems under uncertainties.

A stochastic programming with imprecise probabilities model for planning water resources systems under multiple uncertainties

In this study, a stochastic programming with imprecise probabilities (SP-IP) model is proposed for planning water resources systems. The SP-IP model is capable of addressing multiple uncertainties in the forms of intervals with random boundaries and imprecise probability distributions. The stochastic optimization model can be transformed into a deterministic equivalence in a straightforward manner. A case study of regional water resources allocation is used to demonstrate the applicability of the proposed model. Results indicate that the total net benefits would be decreased with increased probabilities of occurrence, reflecting a potential trade-off between economic benefits and associated risks. The SP-IP model is also capable of providing a variety of decision alternatives under different scenarios of water policies, which is useful for water managers to formulate an appropriate water management policy in an uncertain environment.

Costs and benefits of differences in the timing of greenhouse gas emission reductions

Most modelling studies that explore long-term greenhouse gas mitigation scenarios focus on cost-efficient emission pathways towards a certain climate target, like the internationally agreed target to keep global temperature increase below 2 °C compared to pre-industrial levels (the 2 °C climate target). However, different timing of reductions lead to different transient temperature increase over the course of the century and subsequently to differences in the time profiles of not only the mitigation costs but also adaptation costs and residual climate change damage. This study adds to the existing literature by focussing on the implication of these differences for the evaluation of a set of three mitigation scenarios (early action, gradual action and delayed action), all three limiting global temperature increase below 2 °C above pre-industrial levels, using different discount rates. The study shows that the gradual mitigation pathway is, for these discount rates, preferred over early or delayed action in terms of total climate costs and net benefits. The relative costs and benefits of the early or delayed mitigation action scenarios, in contrast, do strongly depend on the discount rate applied. For specific discount rates, these pathways might therefore be preferred for other reasons, such as reducing long-term uncertainty in climate costs by early action.

Adding Value with Benefit-Cost Analysis: Forecasting Net Social Benefit from Impacts of Slot Machine Gambling in Maryland

The estimated impacts, benefits, and costs of legalizing slot machines in Maryland are analyzed building on and contrasting with results from an impact analysis. The analysis provides estimates of the components and the total net benefits to the state and its citizens; the role of uncertainty, distributional impacts, and a basic tax alternative. The results forecast mostly positive net benefits for Maryland both in comparison to doing nothing and in comparison to raising an equivalent amount in taxes. However, if slot revenue raised from the lower income population is given more weight, then doing nothing or raising taxes appears to be preferred.

Comparative efficiency research (COMER): meta-analysis of cost-effectiveness studies.

BackgroundThe aim of this study was to create a new meta-analysis method for cost-effectiveness studies using comparative efficiency research (COMER).MethodsWe built a new score named total incremental net benefit (TINB), with inverse variance weighting of incremental net benefits (INB). This permits determination of whether an alternative is cost-effective, given a specific threshold (TINB > 0 test). Before validation of the model, the structure of dependence between costs and quality-adjusted life years (QoL) was analysed using copula distributions. The goodness-of-fit of a Spanish prospective observational study (n = 498) was analysed using the Independent, Gaussian, T, Gumbel, Clayton, Frank and Placket copulas. Validation was carried out by simulating a copula distribution with log-normal distribution for costs and gamma distribution for disutilities. Hypothetical cohorts were created by varying the sample size (n: 15–500) and assuming three scenarios (1-cost-effective; 2-non-cost-effective; 3-dominant). The COMER result was compared to the theoretical result according to the incremental cost-effectiveness ratio (ICER) and the INB, assuming a margin of error of 2,000 and 500 monetary units, respectively.ResultsThe Frank copula with positive dependence (−0.4279) showed a goodness-of-fit sufficient to represent costs and QoL (p-values 0.524 and 0.808). The theoretical INB was within the 95% confidence interval of the TINB, based on 15 individuals with a probability > 80% for scenarios 1 and 2, and > 90% for scenario 3. The TINB > 0 test with 15 individuals showed p-values of 0.0105 (SD: 0.0411) for scenario 1, 0.613 (SD: 0.265) for scenario 2 and < 0.0001 for scenario 3.ConclusionsCOMER is a valid tool for combining cost-effectiveness studies and may be of use to health decision makers.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2288-14-139) contains supplementary material, which is available to authorized users.

A systematic review and economic evaluation of diagnostic strategies for Lynch syndrome.

Lynch syndrome (LS) is an inherited autosomal dominant disorder characterised by an increased risk of colorectal cancer (CRC) and other cancers, and caused by mutations in the deoxyribonucleic acid (DNA) mismatch repair genes. To evaluate the accuracy and cost-effectiveness of strategies to identify LS in newly diagnosed early-onset CRC patients (aged < 50 years). Cascade testing of relatives is employed in all strategies for individuals in whom LS is identified. Systematic reviews were conducted of the test accuracy of microsatellite instability (MSI) testing or immunohistochemistry (IHC) in individuals with CRC at risk of LS, and of economic evidence relating to diagnostic strategies for LS. Reviews were carried out in April 2012 (test accuracy); and in February 2012, repeated in February 2013 (economic evaluations). Databases searched included MEDLINE (1946 to April week 3, 2012), EMBASE (1980 to week 17, 2012) and Web of Science (inception to 30 April 2012), and risk of bias for test accuracy was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) quality appraisal tool. A de novo economic model of diagnostic strategies for LS was developed. Inconsistencies in study designs precluded pooling of diagnostic test accuracy results from a previous systematic review and nine subsequent primary studies. These were of mixed quality, with significant methodological concerns identified for most. IHC and MSI can both play a part in diagnosing LS but neither is gold standard. No UK studies evaluated the cost-effectiveness of diagnosing and managing LS, although studies from other countries generally found some strategies to be cost-effective compared with no testing. The de novo model demonstrated that all strategies were cost-effective compared with no testing at a threshold of £20,000 per quality-adjusted life-year (QALY), with the most cost-effective strategy utilising MSI and BRAF testing [incremental cost-effectiveness ratio (ICER) = £5491 per QALY]. The maximum health benefit to the population of interest would be obtained using universal germline testing, but this would not be a cost-effective use of NHS resources compared with the next best strategy. When the age limit was raised from 50 to 60 and 70 years, the ICERs compared with no testing increased but remained below £20,000 per QALY (except for universal germline testing with an age limit of 70 years). The total net health benefit increased with the age limit as more individuals with LS were identified. Uncertainty was evaluated through univariate sensitivity analyses, which suggested that the parameters substantially affecting cost-effectiveness: were the risk of CRC for individuals with LS; the average number of relatives identified per index patient; the effectiveness of colonoscopy in preventing metachronous CRC; the cost of colonoscopy; the duration of the psychological impact of genetic testing on health-related quality of life (HRQoL); and the impact of prophylactic hysterectomy and bilateral salpingo-oophorectomy on HRQoL (this had the potential to make all testing strategies more expensive and less effective than no testing). The absence of high-quality data for the impact of prophylactic gynaecological surgery and the psychological impact of genetic testing on HRQoL is an acknowledged limitation. Results suggest that reflex testing for LS in newly diagnosed CRC patients aged < 50 years is cost-effective. Such testing may also be cost-effective in newly diagnosed CRC patients aged < 60 or < 70 years. Results are subject to uncertainty due to a number of parameters, for some of which good estimates were not identified. We recommend future research to estimate the cost-effectiveness of testing for LS in individuals with newly diagnosed endometrial or ovarian cancer, and the inclusion of aspirin chemoprevention. Further research is required to accurately estimate the impact of interventions on HRQoL. This study is registered as PROSPERO CRD42012002436. The National Institute for Health Research Health Technology Assessment programme.

Energy, economics, and water use efficiency of chickpea (Cicer arietinum L.) cultivars in Vertisols of semi-arid tropics, India

Pulses play a major role in providing overall prosperity to the small and marginal farmers through nutritional security by meeting their dietary protein requirements and improving production base through conservation of natural resources. Inclusion of pulses in the cropping system as a crop rotation improves soil fertility and crop productivity of cereals and oil seeds. Chickpea is one of the important pulses cultivated in Vertisols during winter season. We examined chickpea cultivars for energy use efficiency, economics, physiological efficiency and water use efficiency (WUE) under different rainfall situations for their sustainable yield and overall profit, in Vertisols of semi-arid tropics of South India. Results revealed that low input energy and high grain and stover yields of cultivars result in higher total output energy and net benefit energy. Higher dry matter efficiency of 0.702 was observed with medium-duration cultivar, whereas WUE was higher in short-duration cultivar followed by medium-duration cultivar. We conclude that medium- duration cultivar and short-duration cultivar are more suitable for the SAT region in terms of greater energy benefits, higher income per unit area, physiological efficiency and water use efficiency. Thus short-duration cultivar could be cultivated during normal to above normal rainfall years and during normal to drought years in winter season on residual soil moisture in Vertisols medium-duration cultivar for higher energy efficiency and economics.

A multi-level Taguchi-factorial two-stage stochastic programming approach for characterization of parameter uncertainties and their interactions: An application to water resources management

This paper presents a multi-level Taguchi-factorial two-stage stochastic programming (MTTSP) approach for supporting water resources management under parameter uncertainties and their interactions. MTTSP is capable of performing uncertainty analysis, policy analysis, factor screening, and interaction detection in a comprehensive and systematic way. A water resources management problem is used to demonstrate the applicability of the proposed approach. The results indicate that interval solutions can be generated for the objective function and decision variables, and a variety of decision alternatives can be obtained under different policy scenarios. The experimental data obtained from the Taguchi’s orthogonal array design are helpful in identifying the significant factors affecting the total net benefit. Then the findings from the multi-level factorial experiment reveal the latent interactions among those important factors and their curvature effects on the model response. Such a sequential strategy of experimental designs is useful in analyzing the interactions for a large number of factors in a computationally efficient manner.

Integrated hydrologic–economic decision support system for groundwater use confronting climate change uncertainties in the Tunuyán River basin, Argentina

This study presents an integrated hydrologic–economic model as decision support system for groundwater use and incorporates uncertainties of climate change. The model was developed with the Vensim software (Ventana Systems) for system dynamic simulations. The software permitted the integration of economic variables along with hydrologic variables, in a unified format with the aim of evaluating the economic impacts of climate change on arid environments. To test the model, we applied it in one of the upper Tunuyan River sub-basin, located in the Mendoza Province (Argentina), where irrigation comes from groundwater. The model defines the best mix of crops and the total land use required to maximize the total river sub-basin monetary income, considering as a limit the amount of water that does not exceed the natural annual aquifer recharge. To estimate the impacts of climatic changes, four scenarios were compared: the business as usual (with the number of existing wells) in a dry year with a temperature increase of 4 °C; the business as usual in a wet year with an increase in temperature of 1.1 °C; an efficient use of wells in a dry year and a temperature increase of 4 °C and an efficient use of wells in a wet year with a temperature increase of 1.1 °C. Outputs calculated by the model were: land use per crop, total sub-basin net benefit, total sub-basin water extraction, water extraction limit depending on river discharge and total number of wells required to irrigate the entire area. Preliminary results showed that the number of existing wells exceeded the optimized number of wells required to sustainably irrigate the entire river sub-basin. Results indicated that in an average river discharge year, if wells were efficiently used, further rural development would be possible, until the limit of 350 million m3 of water extraction per year was reached (650 million m3 for a wet year and 180 million m3 for a dry year). The unified format and the low cost of the software license make the model a useful tool for Water Resources Management Institutions, particularly in developing countries.

Abstract P6-07-09: What should be done after PHARE and HERA? Using value of information analysis as a guide

Abstract Background: Adjuvant trastuzumab therapy totaling 12 months (AT-12) is the current standard of care in the treatment of early-stage, HER-2/neu amplified breast cancer. Two studies, PHARE and HERA, examined whether the duration of adjuvant trastuzumab should be decreased safely to 6 months (AT-6) or increased to 2 years (AT-24), respectively. Could the implementation of value of information (VOI) analysis inform future clinical trial priority setting in this sphere? Methods: A Markov health-state transition model was employed to compare 3 adjuvant therapy options: AT-12, AT-6, and AT-24. Patients transitioned through 3 health states, disease free, metastatic recurrence, and death, over 3-month time intervals. The simulation was run using a lifetime time horizon. Transition probabilities of the health states in the AT-12 cohort were estimated from the National Surgical Adjuvant Breast and Bowel Project B-31 and North Central Cancer Treatment Group N9831 trials. Based on the efficacy assumptions that provided the foundation for HERA, the AT-24 probabilities were imputed. AT-6 transition probabilities were assumed to equal AT-12 probabilities. Health outcomes were measured in quality adjusted life years (QALY) and costs in 2012 United States dollars. Health outcomes and costs were discounted to the present value by 5% annually, compounded quarterly. Result: In the reference case, AT-24 had an incremental cost-effectiveness ratio of $57,784/QALY. Probabilistic sensitivity analysis revealed that AT-24 was likely to be 0.3%, 11%, 58%, and 93% cost effective at a threshold willingness-to-pay (WTP) of $20,000, $40,000, $60,000, and $80,000/QALY, respectively. At a WTP threshold of 65,000, the expected VOI payoff from conducting the HERA trial was computed as $204,692 per patient treated per year. Conversely, AT-6 would be expected to cost $100,592 less than AT-12 over a patient's life, corresponding to an expected $249,564 per patient per year payoff for the PHARE trial. Since neither PHARE nor HERA were able to achieve their primary objectives, a new trial testing the duration of trastuzumab could be considered. Employing the same model, AT for 9 months would be expected to save $50,596 per patient compared to AT-12. The VOI of such a trial is estimated to be $224,504 per patient treated per year. Conclusion: Despite the results of PHARE and HERA, VOI analysis suggests that a non-inferiority trial examining 9 months of AT compared to AT-12 should be considered. The actual value of such a trial may be even greater if new HER-2 targeted therapies may be added to AT in the future. However, determining the total net benefit to society of performing such research requires information on its associated budgetary outlays. Cooperative groups should make the their individual trial expenses public to facilitate improved collective decision-making on future trials. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-07-09.

INTEGRATED STEPWISE APPROACH FOR OPTIMAL WATER ALLOCATION IN IRRIGATION CANALS

ABSTRACTOptimal water management in irrigation networks should be an integrated approach which includes both canal and field systems. Integrated optimal water management of irrigation networks requires consideration of both optimal allocation of water among different crops at field level, and optimal water delivery scheduling at the canal level, which is often neglected. In this study, an integrated stepwise approach has been presented for considering both farm‐ and canal‐level optimization problems. Three modules are proposed for the optimization model. In the first module, crop–water production functions for different crops are produced, and optimal seasonal allocation of available water among several crops is determined using an LP algorithm. The objective function of this module is to maximize total net benefit of all crops. The second module takes the optimal allocated water to each crop from the first module, and determines its optimal distribution through the growing season for each crop, such that the total yield at the end of the season is maximized. Taking into account the output of the second module, and cultivated area of each crop, the water requirement volume for each secondary canal is computed. The third module determines optimal water delivery scheduling among outlets of the secondary canal using a genetic algorithm (GA). The objective of the third module is to minimize canal flow, and to maximize delivery adequacy and beneficial water delivery duration. The decision variables are delivery discharge to each outlet, the number of outlets grouped in a block which receive water sequentially, and the sequence of water delivery to the outlets in each block. The proposed approach was applied on the K canal of the Moghan Irrigation Network in the north‐west of Iran. The optimal water delivery scheduling of a secondary canal, based on the optimal water allocation among several crops, and intra‐seasonal irrigation scheduling are presented, which shows the utility of the integrated approach. Copyright © 2013 John Wiley &amp; Sons, Ltd.

An integrated approach for water resources decision making under interactive and compound uncertainties

In recent years, the issue of water allocation among competing users has been of great concern for many countries due to increasing water demand from population growth and economic development. In water management systems, the inherent uncertainties and their potential interactions pose a significant challenge for water managers to identify optimal water-allocation schemes in a complex and uncertain environment. This paper thus proposes a methodology that incorporates optimization techniques and statistical experimental designs within a general framework to address the issues of uncertainty and risk as well as their correlations in a systematic manner. A water resources management problem is used to demonstrate the applicability of the proposed methodology. The results indicate that interval solutions can be generated for the objective function and decision variables, and a number of decision alternatives can be obtained under different policy scenarios. The solutions with different risk levels of constraint violation can help quantify the relationship between the economic objective and the system risk, which is meaningful for supporting risk management. The experimental data obtained from the Taguchi's orthogonal array design are useful for identifying the significant factors affecting the means of total net benefits. Then the findings from the mixed-level factorial experiment can help reveal the latent interactions between those significant factors at different levels and their effects on the modeling response.

A Nash Approach to Planning Merchant Transmission for Renewable Resource Integration

Major transmission projects are needed to integrate and to deliver renewable energy (RE) resources. Cost recovery is a serious impediment to transmission investment. A negotiation methodology is developed in this study to guide transmission investment for RE integration. Built on Nash bargaining theory, the methodology models a negotiation between an RE generation company and a transmission company for the cost sharing and recovery of a new transmission line permitting delivery of RE to the grid. Findings from a six-bus test case demonstrate the Pareto efficiency of the approach as well as its fairness, in that it is consistent with one commonly used definition of fairness in cooperative games, the Nash cooperative solution. Hence, the approach could potentially be used as a guideline for RE investors. The study also discusses the possibility of using RE subsidies to steer the negotiated solution towards a system-optimal transmission plan that maximizes total net benefits for all market participants. The findings suggest that RE subsidies can be effectively used to achieve system optimality when RE prices are fixed through bilateral contracts but have limited ability to achieve system optimality when RE prices are determined through locational marginal pricing. This limitation needs to be recognized in the design of RE subsidies.