Optimal Flood Control Research Articles

Research on multi-objective joint optimal flood control model for cascade reservoirs in river basin system

As the large-scale cascaded reservoirs have been developed rapidly in recent years, river basin flood control (RBFC) has become a complex, multi-objective and multi-reservoir problem. In order to realize the optimal operation and management of reservoirs in mainstreams and branches, this paper presents a generalized multi-objective flood control model (MOFCM) for joint optimal dispatching of cascade reservoirs, which is applied to cascade reservoirs in lower reaches of Jinsha River and Three Gorges Reservoir in Yangtze River (JFCR–TGR). Meanwhile, a multi-objective cultural self-adaptive electromagnetism-like mechanism (MOSEM) algorithm is introduced to solve RBFC problem. In the case study, comparing with the natural runoff of the Chuan River, the maximum release of optimal schemes is lesser, its reduced range is from 1727 to 12,887 m3/s and the flood peak deduction rate is from 6.4 to 48 %. Results of case studies demonstrate that MOFCM is practicable and efficient for multipurpose multi-reservoir flood control. The optimal operation schemes obtained by MOSEM in JFCR–TGR system can be used to assist the decision makers in choosing the most efficient scheme. Furthermore, MOFCM can accomplish multiple-object optimization effectively under various scheduling situations.

基于EDA与GA算法的水库群短期防洪优化调度研究

针对水库群短期防洪调度，建立了以下游防洪控制站点最大洪峰流量最小为目标、加入马斯京根演算作为约束条件的水库群防洪优化调度模型。由于马斯京根河道演算法的滞时，加重了维数灾难题，探讨采用分布估计算法求解模型。以西江流域龙滩、百色水库群优化调度为例，分别采用分布估计算法、遗传算法进行模型求解，试验表明：分布估计算法比遗传算法收敛速度更快，并能够得到较好削减洪峰效果。 Since the Muskingum flood routing is used in reservoir operation for short-time flood control, the curse of dimensionality is aggravated due to the time-lags of food routing. In order to solve this problem, a re-servoirs optimal flood control operation model is established to minimize the flood peak of the down-stream flood control station with the formula of Muskingum as the additional constraints. The Longtan and Bose reservoirs in the Xijiang Basin are used as a case study. The Estimation of Distribution Algorithm (EDA) is proposed to solve the optimal model, and the results are compared with that of the Genetic Algorithm (GA). The experiment demonstrates that the EDA outperforms the GA in terms of the convergence rate and the flood peak reduction.

Optimal flood control and dispatching decision for cascade sluice groups in irrigation channels using a hybrid ant colony-genetic algorithm

Optimal flood control and dispatching decision for cascade sluice groups in irrigation channels using a hybrid ant colony-genetic algorithm

An Improved Contract Net Protocol with Multi-Agent for Reservoir Flood Control Dispatch

Contract Net Protocol (CNP) has been widely used in solving the problems of multi-Agent cooperates and reservoir flood control optimization dispatch. This paper designs an Agent functional module based on the multi-Agent coordinated the construction of reservoir flood control optimization dispatch and the corresponding Agent to solve the problem of classical CNP in the Agent communication aspect, to enhance the efficiency of reservoir optimization dispatch and to improve the insufficiency of the classical CNP in the application of reservoir flood control dispatcher. Then, the capacity factor and the cooperation level are introduced in the module. Experiments are conducted on the Agentbuilder simulation platform to simulate reservoir flood control optimization dispatching with the improved CNP. The simulation results show the communication interactive efficiency and the performance of new protocol is superior to those of the classical CNP.

Guiding rational reservoir flood operation using penalty-type genetic algorithm

Real-time flood control of a multi-purpose reservoir should consider decreasing the flood peak stage downstream and storing floodwaters for future usage during typhoon seasons. This study proposes a reservoir flood control optimization model with linguistic description of requirements and existing regulations for rational operating decisions. The approach involves formulating reservoir flood operation as an optimization problem and using the genetic algorithm (GA) as a search engine. The optimizing formulation is expressed not only by mathematical forms of objective function and constraints, but also by no analytic expression in terms of parameters. GA is used to search a global optimum of a mixture of mathematical and nonmathematical formulations. Due to the great number of constraints and flood control requirements, it is difficult to reach a solution without violating constraints. To tackle this bottleneck, the proper penalty strategy for each parameter is proposed to guide the GA searching process. The proposed approach is applied to the Shihmen reservoir in North Taiwan for finding the rational release and desired storage as a case study. The hourly historical data sets of 29 typhoon events that have hit the area in last thirty years are investigated bye the proposed method. To demonstrate the effectiveness of the proposed approach, the simplex method was performed. The results demonstrated that a penalty-type genetic algorithm could effectively provide rational hydrographs to reduce flood damage during the flood operation and to increase final storage for future usages.

Multireservoir Flood-Control Optimization with Neural-Based Linear Channel Level Routing Under Tidal Effects

In order to determine the optimal hourly releases from reservoirs under the estuary tidal effects during typhoon periods, this paper develops a generalized multipurpose multireservoir optimization model for basin-scale flood control. The model objectives include: preventing the reservoir dam and the downstream river embankment from overtopping, and meeting reservoir target storage at the end of flood. The model constraints include the reservoir operations and the neural-based linear channel level routing. The proposed channel level routing developed from the feed-forward back-propagation neural network is employed to estimate the downstream water levels. The developed optimization model has been applied to the Tanshui River Basin system in Taiwan. The results obtained by the optimization model, in contrast to historical records, demonstrate successfully the practicability in solving the problem of flood control operations.

Rebuilding New Orleans: Editor's Introduction

The Review Articles section of this issue is devoted to real estate issues involved in rebuilding New Orleans in the wake of Hurricane Katrina. This introductory essay describes the recent economic history of the New Orleans metropolitan area and its central city. Compared to Chicago in 1871 and San Francisco in 1906 at the time of their disasters, the economy of New Orleans was stagnant when the hurricane struck. Rebuilding has proceeded very slowly. The essay also sets out some fundamental economic issues in rebuilding the city. The flood control system must be repaired and upgraded because its failure to perform as expected was found to be responsible for most of the flooding. A simple economic model is introduced to show that, if the optimal flood control system is put into place and other critical public services are restored, the private sector will rebuild New Orleans at the economically optimal scale. Additional research is needed to make the simple model more realistic.

Optimal flood control in multireservoir cascade systems with deterministic inflow forecasts

This article presents the formal analysis of a problem of the optimal flood control in systems of serially connected multiple water reservoirs. It is assumed, that the basic goal is minimization of the peak flow measured at a point (cross-section) located downstream from all reservoirs and that inflows to the system are deterministic. A theorem expressing sufficient conditions of optimality for combinations of releases from the reservoirs is presented together with the relevant proof. The main features of the optimal combinations of controls are thoroughly explained. Afterwards, two methods of determining the optimal releases are presented. Finally, the results of the application of the proposed methodology to a small, four reservoir system are presented.

On the application of fuzzy sets theory to the optimal flood control problem arising in water resources systems

Abstract We first survey the application of fuzzy sets theory to various problems occurring in water resources systems. The problem of optimal flood control planning by an appropriate integration of structural and non-structural measures with the objective of optimizing the flood damage reduction due to recurrent floods is modeled via fuzzy sets methodologies. A two level optimization model appropriate for planning decisions first on a regional or local level and then on a national level is proposed. A third phase involving coordination is appended. In particular, a fuzzy optimization model involving an adroit combination of fuzzy dynamic programming-type reasoning and a branch and bound-type search procedure is offered as a more utilitarian approach than its crisp equivalent. The performance of the algorithm is illustrated with an example.

Model for real-time optimal flood control operation of a reservoir system

A methodology and model have been developed for the real-time optimal flood operation of river-reservoir systems. This methodology is based upon combining a nonlinear programming model with a flood-routing simulation model within an optimal control framework. The generalized reduced gradient code GRG2 is used to perform the nonlinear optimization and the simulator is the U.S. National Wheather Service DWOPER code. Application of the model is illustrated through a case study of Lake Travis on the Lower Colorado River in Texas.

Optimal Flood Control System based on Flood Inundation probability

Optimal Flood Control System based on Flood Inundation probability

A STUDY OF FLOOD INUNDATION PROBABILITY IN TIME AND SPACE

In order to establish the optimal flood control system with the comprehensive criteria on the whole river basin, it is necessary to examine the effects of flood control projects in the system consisting of multi-subbasins and multi-defence points on the flood inundation probability in time and space. In this paper, firstly, the flood probabilities in time and space among the subbasins are assumed through the stochastic structures of hourly rainfall and the runoff system model. Secondly, their probabilities are transformed into the flood inundation probabilities at multi-defence points in the river basin based on the flood routing model including the effect of dam control and overflow at the point being lack of river capacity, and the shift operation on non-homogeneous finite state Markov chain. Those estimated flood inundation probabilities will be introduced into the decision model of flood control system.

Forecasting and Optimal Flood Control for Reservoirs with Hydroelectric Plants

Description, identification of a generalized threshold model with integrated threshold elements and its application to forecasting floods for reservoirs with hydro-electric plants are discussed in this paper. Based on this model, a theorem of optimal control of floods for the reservoir aiming on maximum of hydroelectricity output by the plant during the flood period is also given in the paper. This theorem shows the optimal control rule under some assumptions is really independent of the target function. Comparisons of the predicted and the recorded floods, and of the optimal and the com-mon control of floods are graphically showed with the data of real observations.