Water supply operations during drought: A discrete hedging rule

1995 ◽  
Vol 82 (1) ◽  
pp. 163-175 ◽  
Author(s):  
Jhih-Shyang Shih ◽  
Charles ReVelle
Keyword(s):  
Water Supply ◽  
Hedging Rule ◽  
Discrete Hedging

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
Keyword(s):  
Water Supply ◽  
Research Work ◽  
Water Shortage ◽  
Pareto Optimal ◽  
Time Varying ◽  
Pareto Optimal Front ◽  
Reservoir Performance ◽  
Supply Reduction ◽  
Discrete Hedging ◽  
Near Future

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.

scholarly journals Simulation of Multipurpose Reservoir Operation with Hedging Rules

2018 ◽  
Vol 7 (3.12) ◽  
pp. 594
Author(s):  
K Sasireka ◽  
T R Neelakantan ◽  
S Suriyanarayanan
Keyword(s):  
Water Supply ◽  
Reservoir Operation ◽  
Hedging Rule ◽  
Municipal Water Supply ◽  
Storage Reservoirs ◽  
Hedging Rules ◽  
Electricity Power ◽  
Multipurpose Reservoir ◽  
Operating Rule

Reservoir operation plays an important role in the economic development of a region. The storage reservoirs are not only useful for supplying water for municipal and irrigation purpose, but also act as a protection barrier form flood, and the stored water can be used for generation of electricity power as well. To meet the objectives for which the reservoir was planned, it is vital to formulate guidelines for the operation of reservoir. This can be achieved by systematic operation of the system, and by the use of systematic and simplified rule curve for the operation of reservoir. Hedging rules are popular in drinking and irrigation water supply. Application of hedging is now gaining focus for hydropower power reservoir operation. In the present study, attempt has been made to formulate a new operating rule for multipurpose reservoir using hedging rules and the developed model was applied to a case study of Bargi reservoir in the Narmada basin in India. In order to increase the reliability of water supply for municipal, irrigation and average annual power production, the new operating rule has been developed using Standard Operation Policy (SOP) and hedging rule according to the priority of release for different purposes. The hedging rule based simulation model satisfies 97.5% of municipal water supply which is more than 8.25% of the present operational policy. The spill of the reservoir is decreased by 57 % compared to present policy. The performances of different hedging rules were compared with that of a new standard operating policies and the superiority of the hedging rules are discussed in this paper. 

scholarly journals Integrated Operation of Multi-Reservoir and Many-Objective System Using Fuzzified Hedging Rule and Strength Pareto Evolutionary Optimization Algorithm (SPEA2)

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 1995
Author(s):  
Alireza B. Dariane ◽  
Mohammad M. Sabokdast ◽  
Farzane Karami ◽  
Roza Asadi ◽  
Kumaraswamy Ponnambalam ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Optimization Algorithm ◽  
Water Losses ◽  
Weap Model ◽  
Hedging Rule ◽  
Environmental Objectives ◽  
Hedging Rules ◽  
Integrated Operation ◽  
Objective System ◽  
Discrete Hedging

In this paper, a many-objective optimization algorithm was developed using SPEA2 for a system of four reservoirs in the Karun basin, including hydropower, municipal and industrial, agricultural, and environmental objectives. For this purpose, using 53 years of available data, hedging rules were developed in two modes: with and without applying fuzzy logic. SPEA2 was used to optimize hedging coefficients using the first 43 years of data and the last 10 years of data were used to test the optimized rule curves. The results were compared with those of non-hedging methods, including the standard operating procedures (SOP) and water evaluation and planning (WEAP) model. The results indicate that the combination of fuzzy logic and hedging rules in a many-objectives system is more efficient than the discrete hedging rule alone. For instance, the reliability of the hydropower requirement in the fuzzified discrete hedging method in a drought scenario was found to be 0.68, which is substantially higher than the 0.52 from the discrete hedging method. Moreover, reduction of the maximum monthly shortage is another advantage of this rule. Fuzzy logic reduced 118 million cubic meters (MCM) of deficit in the Karun-3 reservoir alone. Moreover, as expected, the non-hedging SOP and WEAP model produced higher reliabilities, lower average storages, and less water losses through spills.

scholarly journals Storage targets optimization embedded with analytical hedging rule for reservoir water supply operation

2017 ◽  
Vol 18 (2) ◽  
pp. 622-629 ◽  
Author(s):  
Jing Wang ◽  
Tiesong Hu ◽  
Xiang Zeng ◽  
Muhammad Yasir
Keyword(s):  
Water Supply ◽  
Water Shortage ◽  
Water Release ◽  
Reservoir Water ◽  
Hedging Rule ◽  
New Model ◽  
Proposed Model ◽  
Maximum Water ◽  
Period Model

Abstract A two-period model is widely used to derive optimal hedging rules for reservoir water supply operation, often with storage targets as the goal to conserve water for future use. However, the predetermined storage targets adopted in the two-period model result in shortsighted decisions without considering the control of long-term reservoir operation. The purpose of this paper is to propose a new model to seek a more promising water supply operation policy by embedding the hedging rule derived from the two-period model in an optimization program for storage targets. Two modules are incorporated in the new model: the two-period model for optimizing water release decisions in each period with given storage targets and the optimization module to determine the optimal values of storage targets for connecting different periods. The Xujiahe water supply system is taken as a case study to verify the effectiveness of the proposed model. The results demonstrate that the new model is superior to others based on standard operation policy or rule curves during droughts and reduces the maximum water shortage.

Enumeration and Identification of Asbestos Fibres in Water

1974 ◽  
Vol 32 ◽  
pp. 526-527 ◽  
Author(s):  
O. Mudroch ◽  
J. R. Kramer
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Drainage Basin ◽  
Lake Superior ◽  
Research Work ◽  
List Type ◽  
The West ◽  
Asbestos Fibre ◽  
Amphibole Asbestos

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.

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