scholarly journals A Simulation-Optimization System to Assess Dam Removal With a Focus on Environmental Degradations at Downstream

2021 ◽  
Author(s):  
Mahdi Sedighkia ◽  
Asghar Abdoli
Keyword(s):  
Reservoir Operation ◽  
Dam Removal ◽  
Vulnerability Index ◽  
Optimization Models ◽  
Physical Habitat ◽  
Efficiency Coefficient ◽  
Dissolved Oxygen Tension ◽  
Natural Flow ◽  
Habitat Simulation

Abstract The present study proposes and evaluates an integrated framework to assess dam removal in which downstream river habitats and reservoir operation were simulated in three different statuses including conventional reservoir operation optimization, optimal release considering environmental aspects in the structure of the optimization model and natural flow. Fuzzy physical habitat simulation was used to assess physical habitats. Moreover, ANFIS based model was utilized to simulate thermal tension and dissolved oxygen tension at downstream habitats. Particle swarm optimization was applied in the optimization models. Results of the optimization models and habitat suitability in the natural flow were compared by applying different measurement indices including reliability index, vulnerability index, The Nash–Sutcliffe model efficiency coefficient (NSE) and root mean square error (RMSE). Based on the results in the case study, reliability of water supply might be reduced in the optimal release for environment and demand. Furthermore, optimal release for environment is not able to protect downstream aquatics habitats properly. Thus, if protecting downstream habitats is aimed, dam removal might be logic in the case study. The main limitation of the proposed method is high computational complexities.

scholarly journals Dominant Fish and Macroinvertebrate Response to Flow Changes of the Geum River in Korea

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 942 ◽  
Author(s):  
Hyeongsik Kang ◽  
Byungwoong Choi
Keyword(s):  
Flow Patterns ◽  
Base Flow ◽  
Physical Habitat ◽  
Aquatic Species ◽  
Morphology Change ◽  
Suitability Index ◽  
Natural Flow ◽  
Habitat Simulation ◽  
Target Fish ◽  
The Impact

This study presents the impact of natural flow patterns on downstream aquatic species habitats in a reach of the Geum River, Korea. The study reach is a 13.4 km long, located downstream of the Yongdam Dam. To assess such an impact, this study performed physical habitat simulations. The River2D model was used for the computation of the flow field and morphology, and the Habitat Suitability Index (HSI) model for the habitat simulation. Three habitat variables—flow depth, velocity, and substrate were used. The Zacco platypus and Baetis fuscatus were selected as the target fish and benthic macro-invertebrate, respectively. Using the building block approach (BBA), the scenarios for modifying dam operations were constructed in the study reach. Scenario 1, scenario 2, and scenario 3 were proposed by using the magnitude–duration concept, base flow allocation concept, and seasonally adjusted minimum flow allocation concept, respectively. Simulation results indicated that the scenarios’ effects significantly increased by about 14.3% for the weighted usable area (WUA). In addition, the morphology change with the restoration of flood events was investigated. It was revealed that the morphology change in the physical habitat simulations further increased by about 13% for the WUA. The change of dam operations through natural flow patterns is more advantageous to aquatic species.

scholarly journals Baseflow Contribution to Streamflow and Aquatic Habitats Using Physical Habitat Simulations

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1304 ◽  
Author(s):  
Byungwoong Choi ◽  
Hyeongsik Kang ◽  
Woong Lee
Keyword(s):  
Habitat Suitability ◽  
Water Policy ◽  
Benthic Macroinvertebrate ◽  
Physical Habitat ◽  
University Of Alberta ◽  
Natural Flow ◽  
Habitat Simulation ◽  
Natural Flow Regimes ◽  
The Republic ◽  
The Impact

A scientific understanding of the baseflow contribution to streams and watershed processes is critical when dealing with water policy and management issues. However, most previous studies involving physical habitat simulation have been performed without considering the seepage of water from the underground into streams. Motivated by this, herein, we report an investigation of the impact of baseflow using physical habitat simulations for both dominant fish and benthic macroinvertebrate. The study area was located along the reach of the Ungcheon Stream, located 16.50 km downstream and 11.75 km upstream from the Boryeong Dam in the Republic of Korea. For the physical habitat simulation, Zacco platypus and Baetis fuscatus were selected as the target fish and benthic macroinvertebrate, respectively. The HydroGeoSphere (HGS) model (Aquanty Inc., Waterloo, ON, Canada) and the River2D model (Version 0.95a, University of Alberta, Edmonton, AB, Canada) were used for hydrologic and hydraulic simulations, respectively. The Habitat Suitability Index (HSI) model was used for the habitat simulations. Three habitat variables, flow depth, velocity, and substrate, were used. To assess the impact of baseflow, this study performed a physical habitat simulation using each representative discharge, with and without considering baseflow. It was found that the baseflow effects significantly increase the habitat suitability in the study reach. To restore the aquatic habitat, a scenario for modifying dam operations through natural flow patterns is presented using the Building Block Approach (BBA). In the study, the adjusted minimum flow allocation concept was used. It was revealed that the modified dam operations significantly increased the Weighted Usable Area (WUA) by about 48% for both target species. The results indicate that modifying the dam operations through restoration to natural flow regimes but also through inclusion of the baseflow are advantageous to aquatic fish habitats.

Habitat Elements in River Basin Management and Planning

1987 ◽  
Vol 19 (9) ◽  
pp. 19-29 ◽  
Author(s):  
Edwin E. Herricks ◽  
Maria I. Braga
Keyword(s):  
Water Quality ◽  
River Basin ◽  
River Basin Management ◽  
The United States ◽  
Physical Habitat ◽  
Basin Management ◽  
Habitat Analysis ◽  
Management Procedures ◽  
Habitat Simulation ◽  
Flow Quantity

Comprehensive river basin management mast move beyond narrowly focused programs dealing with water quantity or water quality. A more comprehensive approach to river basin management recognizes that both flow quantity and water quality can be summarized as habitat measures. A number of well developed physical habitat analysis and prediction procedures are presently available. Several computerized systems available from the U.S.Fish and Wildlife Service (Habitat Suitability Index - HSI and PHysical HABitat SIMulation - PHABSIM) provide macrohabitat definition. We have developed a water quality based habitat component which operates effectively for general analysis. With an emphasis on site specific management in the United States, the macrohabitat definition procedures may not meet all river basin management and planning requirements. This paper reviews the results of research which characterizes microhabitat in streams and rivers and provides a valuable extension to basin management procedures.

scholarly journals Internal and external validation of vulnerability indices: a case study of the Multivariate Nursing Home Vulnerability Index

2020 ◽  
Vol 100 (3) ◽  
pp. 1013-1036 ◽  
Author(s):  
Matthew Wilson ◽  
Sandi Lane ◽  
Raghuveer Mohan ◽  
Margaret Sugg
Keyword(s):  
Nursing Home ◽  
External Validation ◽  
Vulnerability Index

scholarly journals A novel remote sensing ecological vulnerability index on large scale: A case study of the China-Pakistan Economic Corridor region

2021 ◽  
Vol 129 ◽  
pp. 107955
Author(s):  
Hongwei Wu ◽  
Bing Guo ◽  
Junfu Fan ◽  
Fei Yang ◽  
Baomin Han ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Large Scale ◽  
Vulnerability Index ◽  
Ecological Vulnerability

scholarly journals A Reservoir Operation Policy Using Inter-Basin Water Transfer for Maximizing Hydroelectric Benefits in Brazil

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2564 ◽  
Author(s):  
Anderson Passos de Aragão ◽  
Patrícia Teixeira Leite Asano ◽  
Ricardo de Andrade Lira Rabêlo
Keyword(s):  
Reservoir Operation ◽  
Network Flow ◽  
Water Transfer ◽  
Energy Deficit ◽  
Generation System ◽  
Operation Rules ◽  
First Case ◽  
Basin Water ◽  
Hydroelectric Plants

The Hydrothermal Coordination problem consists of determining an operation policy for hydroelectric and thermoelectric plants within a given planning horizon. In systems with a predominance of hydraulic generation, the operation policy to be adopted should specify the operation of hydroelectric plants, so that hydroelectric resources are used economically and reliably. This work proposes the implementation of reservoir operation rules, using inter-basin water transfer through an optimization model based on Network Flow and Particle Swarm Optimization (PSO). The proposed algorithm aims to obtain an optimized operation policy of power generation reservoirs and consequently to maximize the hydroelectric benefits of the hydrothermal generation system, to reduce the use of thermoelectric plants, the importation and/or energy deficit and to reduce the cost associated with meeting the demand and reduce CO2 emissions from combustion of fossil fuels used by thermoelectric plants. In order to illustrate the efficiency and effectiveness of the proposed approach, it was evaluated by optimizing two case studies using a system with four hydroelectric plants. The first case study does not consider transfer and water and the second case study uses water transfer between rivers. The obtained results illustrate that the proposed model allowed to maximize the hydroelectric resources of a hydrothermal generation system with economy and reliability.

Deriving reservoir operating rules considering ecological demands of multiple stations

2021 ◽  
pp. 1-59
Author(s):  
Chen Wu ◽  
Yibo Wang ◽  
Jing Ji ◽  
Pan Liu ◽  
Liping Li ◽  
...  
Keyword(s):  
Reservoir Operation ◽  
Flood Control ◽  
Optimization Models ◽  
Ecological Indicator ◽  
Generation Model ◽  
Hydropower Generation ◽  
Rule Curves ◽  
Constraints Model ◽  
Operating Rule ◽  
Operating Rule Curves

Reservoirs play important roles in hydropower generation, flood control, water supply, and navigation. However, the regulation of reservoirs is challenged due to their adverse influences on river ecosystems. This study uses ecoflow as an ecological indicator for reservoir operation to indicate the extent of natural flow alteration. Three reservoir optimization models are established to derive ecological operating rule curves. Model 1 only considers the maximization of average annual hydropower generation and the assurance rate of hydropower generation. Model 2 incorporates ecological objectives and constraints. Model 3 not only considers the hydropower objectives but also simulates the runoff and calculates the ecological indicator values of multiple downstream stations. The three models are optimized by a simulation-optimization framework. The reservoir ecological operating rule curves are derived for the case study of China's Three Gorges Reservoir. The results represent feasible schemes for reservoir operation by considering both hydropower and ecological demands. The average annual power generation and assurance rate of a preferred optimized scheme for Model 3 are increased by 1.06% and 2.50%, respectively. Furthermore, ecological benefits of the three hydrologic stations are also improved. In summary, the ecological indicator ecoflow and optimization models could be helpful for reservoir ecological operations.

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