scholarly journals Season-Dependent Hedging Policies for Reservoir Operation—A Comparison Study

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1311 ◽  
Author(s):  
Nikhil Bhatia ◽  
Roshan Srivastav ◽  
Kasthrirengan Srinivasan

During periods of significant water shortage or when drought is impending, it is customary to implement some kind of water supply reduction measures with a view to prevent the occurrence of severe shortages (vulnerability) in the near future. In the case of operation of a water supply reservoir, this reduction of water supply is affected by hedging schemes or hedging policies. This research work aims to compare the popular hedging policies: (i) linear two-point hedging; (ii) modified two-point hedging; and, (iii) discrete hedging based on time-varying and constant hedging parameters. A parameterization-simulation-optimization (PSO) framework is employed for the selection of the parameters of the compromising hedging policies. The multi-objective evolutionary search-based technique (Non-dominated Sorting based Genetic Algorithm-II) was used to identify the Pareto-optimal front of hedging policies that seek to obtain the trade-off between shortage ratio and vulnerability. The case example used for illustration is the Hemavathy reservoir in Karnataka, India. It is observed that the Pareto-optimal front that was obtained from time-varying hedging policies show significant improvement in reservoir performance when compared to constant hedging policies. The variation in the monthly parameters of the time-variant hedging policies shows a strong correlation with monthly inflows and available water.

2017 ◽  
Vol 19 (6) ◽  
pp. 838-852 ◽  
Author(s):  
Agathoklis Agathokleous ◽  
Chrystalleni Christodoulou ◽  
Symeon E. Christodoulou

Abstract Water authorities in countries facing water shortage problems are implementing intermittent water supply (IWS) policies, as a measure to conserve and control their national water resources. Implementation of such measures affects the behaviour of the water pipe systems during the operation stage. The research work presented herein presents a model simulating the behaviour of urban water distribution networks (WDNs) under normal operating conditions, as well as during a period of IWS operations. The modelling and analysis, based on an eight-year dataset (2003–2010) from a local Water Board, takes into account information related to breakage incidents within the WDN as well as external factors to perform vulnerability assessment of the pipe network. The results of the performed survival and cluster analysis show that during the implementation period of IWS operations, and right after that period, there is a significant increase in the deterioration rate of the affected network. Further, there is a change in the comparative importance of the factors affecting the network condition and their contribution to the WDN vulnerability.


Author(s):  
O. Mudroch ◽  
J. R. Kramer

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.


2019 ◽  
Vol 118 (3) ◽  
pp. 137-152
Author(s):  
A. Shanthi ◽  
R. Thamilselvan

The major objective of the study is to examine the performance of optimal hedge ratio and hedging effectiveness in stock futures market in National Stock Exchange, India by estimating the following econometric models like Ordinary Least Square (OLS), Vector Error Correction Model (VECM) and time varying Multivariate Generalized Autoregressive Conditional Heteroscedasticity (MGARCH) model by evaluating in sample observation and out of sample observations for the period spanning from 1st January 2011 till 31st March 2018 by accommodating sixteen stock futures retrieved through www.nseindia.com by considering banking sector of Indian economy. The findings of the study indicate both the in sample and out of sample hedging performances suggest the various strategies obtained through the time varying optimal hedge ratio, which minimizes the conditional variance performs better than the employed alterative models for most of the underlying stock futures contracts in select banking sectors in India. Moreover, the study also envisage about the model selection criteria is most important for appropriate hedge ratio through risk averse investors. Finally, the research work is also in line with the previous attempts Myers (1991), Baillie and Myers (1991) and Park and Switzer (1995a, 1995b) made in the US markets


Water Policy ◽  
2012 ◽  
Vol 14 (6) ◽  
pp. 977-990 ◽  
Author(s):  
David Baguma ◽  
Jamal H. Hashim ◽  
Syed M. Aljunid ◽  
Michael Hauser ◽  
Helmut Jung ◽  
...  

Having access to a safe water supply is important to improve a person's quality of life. We examine the relationship between the influence of water availability on monthly household expenditures (the dependent variable) and independent variables such as household characteristics, tank size, usage instructions and post-construction guidance, including the management of water-related health risks. The sample consisted of 301 respondents who harvest rainwater in Uganda. A multiple regression analysis was used to analyse the data. The findings show that post-construction guidance and tank size were significant variables. This study suggests the need for a follow-up to improve health after the installation of water supply equipment, i.e., to provide information about water risks, foster reading norms and facilitate the availability and affordability of information sources, e.g., subsidised newspapers and information support devices (computers). Additionally, this study shows the possibility of increased savings due to reduced expenditures on water from vendors and the management of water-related health risks caused by a water shortage, e.g., dehydration. Overall, the study reveals two possible ways to advance policy and health in developing countries: (1) ensuring sufficient post-construction guidance for all water resources; and (2) ensuring a sustainable supply of adequate safe water in households.


2003 ◽  
Vol 48 (10) ◽  
pp. 71-77 ◽  
Author(s):  
J.-T. Kuo ◽  
W.-C. Cheng ◽  
L. Chen

Multipurpose operation is adopted by most reservoirs in Taiwan in order to maximize the benefits of power generation, water supply, irrigation and recreational purposes. A multiobjective approach can be used to obtain trade-off curves among these multipurpose targets. The weighting method, in which different weighting factors are used for different purposes, was used in this research work. In Taiwan, most major reservoirs are operated by rule curves. Genetic algorithms with characteristics of artificial intelligence were applied to obtain the optimal rule curves of the multireservoir system under multipurpose operation in Chou-Shui River Basin in central Taiwan. The model results reveal that different shapes of rule curves under different weighting factors on targets can be efficiently obtained by genetic algorithms. Pareto optimal solutions for a trade-off between water supply and hydropower were obtained and analyzed.


2017 ◽  
Vol 13 (02) ◽  
pp. 18
Author(s):  
Lei Feng ◽  
Chuang Yang ◽  
Wenbin Zheng ◽  
Ping Fu

Urban water supply pipe network is critical infrastructure for the survival of people. Efficient operation of equipment, water supply and water safety are always received great attention from the government and operators. The existing way of manual meter reading and manual inspection has the drawbacks of waste time and labor. To solve this problem, we developed databases, software platforms and mobile terminal APP (Application) based on Android operating system to integrate a remote wireless automatic meter reading system based on the existing remote wireless automatic reading meter devices which are our previous research work. The system realizes the remote monitoring of the pipe network, and it also realizes the remote control of the monitoring nodes, such as the camera shooting, selection of monitoring node's working mode and so on, which data feedback is accurate and timely, monitoring methods is simple, fast and efficient. In addition, compared to traditional methods, the system greatly reduced the manpower and resources, reduce monitoring costs. And the tests and experiments show this remote wireless automatic meter reading and control system is useful and effective.


2020 ◽  
pp. 105-113
Author(s):  
M. Farsi

The main aim of this research is to present an optimization procedure based on the integration of operability framework and multi-objective optimization concepts to find the single optimal solution of processes. In this regard, the Desired Pareto Index is defined as the ratio of desired Pareto front to the Pareto optimal front as a quantitative criterion to analyze the performance of chemical processes. The Desired Pareto Front is defined as a part of the Pareto front that all outputs are improved compared to the conventional operating condition. To prove the efficiency of proposed optimization method, the operating conditions of ethane cracking process is optimized as a base case. The ethylene and methane production rates are selected as the objectives in the formulated multi-objective optimization problem. Based on the simulation results, applying the obtained operating conditions by the proposed optimization procedure on the ethane cracking process improve ethylene production by about 3% compared to the conventional condition.  


2020 ◽  
Vol 17 (2) ◽  
pp. 41-46
Author(s):  
Heba F. Abdelwahab ◽  
Elsayed M. Ramadan ◽  
Abdelazim M. Negm

AbstractIt is acknowledged that providing a safe water supply for all countries is one of the major challenges of the twenty-first century. Egypt is one of the greatest countries affected in Africa and Middle East. The Nile is facing a major water shortage due to the limited water resources and the the demand is growing as a result high population growth and development in industrial and agricultural sectors. This paper has been motivated by the fact that there is no up-to-date literature review of the optimal operation of Water Resources. The analysis of the reviewed literature is structured along five broad branches: (1) Mathematical Optimization Modelling Studies, (2) Numerical Simulation Modelling Studies, (3) Geographical Information Systems “GIS” based Studies, (4) Ecological Studies, (5) Water Reuse Studies. This review is limited to surface water but groundwater has been inexplicitly included. The paper concludes the best way to identify knowledge to cover the gap between water supply and demands and to guide future researches on water resources planning and management.


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