Reservoir Management and Operation

Climate change is one of the most important global environmental challenges, which affects the overall system by
affecting food production, water supply, health, energy, etc. For study purpose Giritale reservoir in Polonnaruwa
district of dry zone in Sri Lanka was selected. Catchment area of the reservoir is 24.3 sq.km and command area is 3075
ha. Data for the reservoir was collected from irrigation department, Colombo and 6 year (2010-2015) rainfall data
collected also from irrigation department. This study investigated the impact of climate change, adaption and
mitigation measures reservoir system. After a review three scenarios were identified. Scenario 1 rainfall increase 15.8%
and temperature increase 8% and scenario2 rainfall increase 14% and temperature increase1.6% and scenario 3 is
rainfall is projected to increase by 48% for the Southwest Monsoon by 2050 and Northeast Monsoon, which occurs in
the drier northern region, is predicted to decrease by 27–29%. For the worst scenario four adaptation measures were
proposed. Among the four only two adaptations could be quantified, and the best adaptation measure was identified.
Among scenario option’s, the scenario 2 is the worst scenario and adaptation measure taken for scenario2consist of
two options. Option1 is changing the crop type and option 2 is increasing the canal efficiency. For option 1 105 days
paddy for Maha and Yala was taken and also green gram for both Maha and Yala was considered and for option2 canal
efficiency increased by 10% . Therefore comparing the results adaptation use of green gram improved the cropping
intensity by 13%.For verification of result actual rainfall data is not enough and also for predicting the climate trend.
Future climate projections indicate that the climate is changing and impacts on agriculture sector can be expected and
Worst climate change scenario for the Gritale scheme is when increasing rainfall 14% and also increase the evaporation
6.4%

Background: While there is growing recognition of the malaria impacts of large dams in sub-Saharan Africa, the cumulative malaria impact of reservoirs associated with current and future dam developments has not been quantified. The objective of this study was to estimate the current and predict the future impact of large dams on malaria in different eco-epidemiological settings across sub-Saharan Africa.

Reservoir management in fields with geomechanical issues such as subsidence and dilation due to injection and production activities is challenging where it is crucial to prevent well failures due to resulting shear or compaction stresses that might lead to serious losses owing to well and facility failures and impact success of production operations. A robust understanding of changes in reservoir parameters that influence subsurface recovery is as important to predict the adverse effects of compaction in the reservoir. The objective of this study is to investigate the effects of injection and production not only on compaction and dilation but also on reservoir fluid flow phenomenon including the significance of rock properties on flow due to changes in permeability in order to outline the significance of decision or control parameters of injection/production along with uncertainty parameters of reservoir rock. The results will provide useful in observing the significance of each parameter on production and recovery. In our study, a full-physics commercial numerical reservoir simulator has been utilized where it is coupled with an optimization and uncertainty tool to investigate the significance of decision parameters such as amount and rate of injection and production as well as the uncertainty parameters such as rock properties with different Young's Modulus. Different rock types are assigned in the geomechanics section due to different Young's modulus on each layer. Different constitutive models are assigned on rock layers. Linear elastic model and nonlinear elastic model are employed. Output stresses, subsidence and displacement vector are used to evaluate the influence of injection and production. Effect of production on compaction with decrease in permeability has been observed under different scenarios that include different operating conditions such as rates and different uncertainty parameters such as rock types with unique Young's modulus and permeability. The significance of each parameter is presented to provide a better understanding on reservoir management for reservoirs where geome-chanical stresses are crucial in decision making on operational constraints and design. Numerical reservoir simulation with geomechanics option is a convenient tool to predict not only the reservoir performance but also the reservoir stresses occurring due to injection and production. The reservoir model with geomechanics-dependent permeability provides a more realistic forecast for recovery compared to the models where geomechanics is ignored. The understanding of effect of injection and production on stresses generated in reservoir enables more optimum operation of wells to minimize such

1] A new criterion for the onset of entrainment of coarse sediment grains is presented here. It is hypothesized that not only the magnitude, but also the duration of energetic near bed turbulent events is relevant in predicting grain removal from the bed surface. It is therefore proposed that the product of force and its duration, or impulse, is a more appropriate and universal criterion for identifying conditions for particle dislodgement. This conjecture is investigated utilizing two theoretical models, representative of two modes of entrainment: saltation and rolling. In these models, instantaneous, highly fluctuating turbulent forces are simulated as short-lived pulses of characteristic magnitude and duration, which transfer adequate fluid momentum to the particle, to trigger its entrainment. The analytical solution of the respective equations of motion is employed in deriving representations of threshold conditions in terms of the impulse characteristics. It is shown that hydrodynamic forces of sufficiently high magnitude are capable of entraining a particle only when they last long enough so that their impulse exceeds a critical value. To illustrate further the validity of the critical impulse concept, as well as extend and generalize its application to different entrainment levels of an individual grain, a novel experimental setup is utilized. This setup facilitates observations of angular displacement of a steel mobile particle in air due to electromagnetic pulses of different magnitude and duration. The experimentally obtained conditions for partial or complete entrainment support the concept of a critical impulse.

Operation of reservoirs is one of the most important and complicated issues in usage of dams that the designers have had challenges with for long. One of the most important solutions is choosing the best study method as well as utilizing the best engineering techniques. By using these methods and techniques, not only the operational method is studied, but also the capacity of reservoir is estimated. The most important methods in determining the capacity of reservoir are: critical period method (mass curve, sequent peak method, working table), optimization methods or system engineering techniques (linear programming, dynamic programming) and simulation method. Optimization is a method that should result in the best answer to a problem based on given purpose and limitations defined as mathematical functions. In this method, the design parameters such as the height of the dam could be estimated using mathematical models. It is also possible to evaluate the approximate operation of reservoir, based on the dam height. This paper aims at investigating the process operational studies of reservoirs. Also, it investigates the potentialities as well as the limitations of computational methods of reservoir functions in simulation and optimization methods. Finally, necessary guides in order to choose a suitable method as well as evaluating the results will be suggested.

In this work, a neuro-fuzzy (NF) simulation study was conducted in order to screen candidate reservoirs for enhanced oil recovery (EOR) projects in Angolan oilfields. First, a knowledge pattern is extracted by combining both the searching potential of fuzzy-logic (FL) and the learning capability of neural network (NN) to make a priori decisions. The extracted knowledge pattern is validated against rock and fluid data trained from successful EOR projects around the world. Then, data from Block K offshore Angolan oilfields are then mined and analysed using box-plot technique for the investigation of the degree of suitability for EOR projects. The trained and validated model is then tested on the Angolan field data (Block K) where EOR application is yet to be fully established. The results from the NF simulation technique applied in this investigation show that polymer, hydrocarbon gas, and combustion are the suitable EOR techniques.

Research has always been a tremendous role in the development of in theory and applied issues. These developments have been reflected in many scientific papers. This paper aims to identify the best papers in the field of optimal reservoir operation. The method used in this research is reviewing of ISI papers taken from the Web of Science. In this regard, 579 papers have been found between 1980 and 2014 that the two words " Reservoir " and " Operation " have been seen in their titles. In fact, the results of this statistical study introduce the top researchers, journals and the leading countries in the field of optimal reservoir operation. The large number of publications in this field indicates that the problem of water resources cannot be solved only by the construction of the dam and it needs more study on optimal operation of water resources.

In this study, a Genetic Algorithm model for optimal operation of a multi-reservoir and multiobjective water resource system in Ghezel Ozan watershed for hydropower generation and flood control is developed. The system is made of two reservoirs in series on the Ghezel Ozan’s river. This model is used for
optimal reservoir operation, allocation of water among different power plants and keeping a part of storage volume to control the probable floods using a definite combination of decision variables (Release of water to the power plants). The model operation for 12 months of a year shows that, the amount of releases in flooding months of the year is more than others.

Social (central) planning is normally used in the literature to optimize the system-wide efficiency and utility of multi-operator systems. Central planning tries to maximize system's benefits by coordinating the operators' strategies and reduce the externalities, assuming that all parties are willing to cooperate. This assumption implies that operators are willing to base their decisions based on group rationality rather than individual rationality, even if increased group benefits results in reduced benefits for some agents. This assumption limits the applicability of social planner's solutions, as perfect cooperation among agents is often infeasible in real world. Recognizing the fact that decisions are normally based on individual rationality in human systems, cooperative game theory methods are normally employed to address the major limitation of social planner's methods. Game theory methods revise the social planner's solution such that not only group benefits are increased, but also there exists no agent whose cooperative gain is less than his non-cooperative gain. However, in most cases, utility is assumed to be transferrable and the literature has not sufficiently focused on non-transferrable utility games. In such games parties are willing to cooperate and coordinate their strategies to increase their benefits, but have no ability to compensate each other to promote cooperation. To a good extent, the transferrable utility assumption is due to the complexity of calculations to find the best response strategies of agents in non-cooperative and cooperative modes, especially in multi-period games. By combining Reinforcement Learning and Nash bargaining solution, this paper develops a new method for applying cooperative game theory to complex multi-period non-transferrable utility games. For illustration, the suggested method is applied to two numerical examples in which two hydropower operators seek developing a fair and efficient cooperation mechanism to- increase their gains.

A real time flood management (forecasting) model is developed for flood operation of the Lower Colorado River-Highland Lake System in Texas. This model combines techniques for one dimensional unsteady flow routing, rainfall runoff modelling, graphical display capability, and interactive software capability. Unsteady flow routing is performed using the United States National Weather Service DWOPER model. The model allows for specification of alternative future precipitation and river level scenarios and operationl controls in addition to real time river levels, reservoir levels, and rainfall.