Operation of a hydropower system considering environmental flow requirements: A case study in La Nga river basin, Vietnam

Babel, Mukand S.; Dinh, Chien Nguyen; Mullick, Md. Reaz Akter; Umamahesh, N. V.

doi:10.1016/j.jher.2011.05.006

Cited by 55 publications

(24 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They determined some environmental flow components (EFCs), such as the maintenance flow, during dry and normal years (Mathews and Richter, 2007). Alternatively, EFRs can be calculated using a method called the range of variability approach (RVA), which in non-parametric analyses calculates EFRs as a range between the 25th and 75th monthly flow percentile (Armstrong et al, 1999;Babel et al, 2012), or in parametric analyses as a range of mean monthly flow (±standard deviation) (Smakhtin et al, 2006;Richter et al, 2012). The advantage of hydrological methods is that they are simple and fast EF methods for use in preliminary assessments or when ecological data sets are not available.…”

Section: Hydrological Methodsmentioning

confidence: 99%

Accounting for environmental flow requirements in global water assessments

Pastor

Ludwig

Biemans

et al. 2014

Hydrol. Earth Syst. Sci.

364

261

View full text Add to dashboard Cite

Abstract. As the water requirement for food production and other human needs grows, quantification of environmental flow requirements (EFRs) is necessary to assess the amount of water needed to sustain freshwater ecosystems. EFRs are the result of the quantification of water necessary to sustain the riverine ecosystem, which is calculated from the mean of an environmental flow (EF) method. In this study, five EF methods for calculating EFRs were compared with 11 case studies of locally assessed EFRs. We used three existing methods (Smakhtin, Tennant, and Tessmann) and two newly developed methods (the variable monthly flow method (VMF) and the Q 90 _Q 50 method). All methods were compared globally and validated at local scales while mimicking the natural flow regime. The VMF and the Tessmann methods use algorithms to classify the flow regime into high, intermediate, and low-flow months and they take into account intra-annual variability by allocating EFRs with a percentage of mean monthly flow (MMF). The Q 90 _Q 50 method allocates annual flow quantiles (Q 50 and Q 90 ) depending on the flow season. The results showed that, on average, 37 % of annual discharge was required to sustain environmental flow requirement. More water is needed for environmental flows during low-flow periods (46-71 % of average low-flows) compared to high-flow periods (17-45 % of average high-flows). Environmental flow requirements estimates from the Tennant, Q 90 _Q 50 , and Smakhtin methods were higher than the locally calculated EFRs for river systems with relatively stable flows and were lower than the locally calculated EFRs for rivers with variable flows. The VMF and Tessmann methods showed the highest correlation with the locally calculated EFRs (R 2 = 0.91). The main difference between the Tessmann and VMF methods is that the Tessmann method allocates all water to EFRs in low-flow periods while the VMF method allocates 60 % of the flow in low-flow periods. Thus, other water sectors such as irrigation can withdraw up to 40 % of the flow during the low-flow season and freshwater ecosystems can still be kept in reasonable ecological condition. The global applicability of the five methods was tested using the global vegetation and the LundPotsdam-Jena managed land (LPJmL) hydrological model. The calculated global annual EFRs for fair ecological conditions represent between 25 and 46 % of mean annual flow (MAF). Variable flow regimes, such as the Nile, have lower EFRs (ranging from 12 to 48 % of MAF) than stable tropical regimes such as the Amazon (which has EFRs ranging from 30 to 67 % of MAF).

show abstract

Section: Hydrological Methodsmentioning

confidence: 99%

Accounting for environmental flow requirements in global water assessments

Pastor

Ludwig

Biemans

et al. 2014

Hydrol. Earth Syst. Sci.

364

261

View full text Add to dashboard Cite

show abstract

“…The electricity volume determines the water volume that should be released to the downstream rivers, and in turn determines the degree of flow regime alteration. Flow regime alteration is the major cause of riverine ecosystem degradation (Bunn and Arthington, 2002;Babel et al, 2011;Kern et al, 2012;Bhatt and Khanal, 2012). Due to the difference of electricity price among different submarkets, the electricity allocation among different submarkets as well as the total generated electricity volume determines the revenue of hydropower producers.…”

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

Portfolio optimisation for hydropower producers that balances riverine ecosystem protection and producer needs

Yin

Zhang

Liu

2014

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. In deregulated electricity markets, hydropower portfolio design has become an essential task for producers. The previous research on hydropower portfolio optimisation focused mainly on the maximisation of profits but did not take into account riverine ecosystem protection. Although profit maximisation is the major objective for producers in deregulated markets, protection of riverine ecosystems must be incorporated into the process of hydropower portfolio optimisation, especially against a background of increasing attention to environmental protection and stronger opposition to hydropower generation. This research seeks mainly to remind hydropower producers of the requirement of river protection when they design portfolios and help shift portfolio optimisation from economically oriented to ecologically friendly. We establish a framework to determine the optimal portfolio for a hydropower reservoir, accounting for both economic benefits and ecological needs. In this framework, the degree of natural flow regime alteration is adopted as a constraint on hydropower generation to protect riverine ecosystems, and the maximisation of mean annual revenue is set as the optimisation objective. The electricity volumes assigned in different electricity submarkets are optimised by the noisy genetic algorithm. The proposed framework is applied to China's Wangkuai Reservoir to test its effectiveness. The results show that the new framework could help to design eco-friendly portfolios that can ensure a planned profit and reduce alteration of the natural flow regime.

show abstract

“…Some of the results have highlighted the losses of the energy sector in modifying reservoir operation rules as an impact of the implementation of environmental flows (YANG et al, 2012;BOODOO et al, 2014). Other studies evidenced a possible compromise between attending to the energy sector and the environment (GÓMEZ et al, 2014;LIECHTI et al, 2015;BABEL et al, 2012;CAI et al, 2013). This article aims to evaluate the financial impacts on the hydroelectric sector due to environmental water allocation, considering the implementation of environmental flows.…”

Section: Introductionmentioning

confidence: 99%

Cost-benefit analysis of reservoir operation scenarios considering environmental flows for the lower stretch of the São Francisco River (Brazil)

Brambilla

Fontes

Medeiros

2017

RBRH

View full text Add to dashboard Cite

Environmental water allocation consists in considering the environment as a licit user of water. The importance of meeting the environment's hydric necessities to assure ecosystem protection is recognized worldwide, however their practical implementation is restricted, requiring impact assessment of the implementation towards the other water users. In this context, this article aims to evaluate the financial impacts on the hydroelectric sector considering environmental flows as reservoir release restrictions. The case study is the lower course of the São Francisco River, a region that presents a strong social and environmental degradation of great importance for Brazilian energy system. The method used to achieve this goal contemplates the construction of reservoir operation scenarios, the mathematical modeling of the water system and the cost-benefit analysis for the energy sector. The simulation points out potential conflicts between the non-consumptive uses. Assessing the cost-benefit analyses for normal and dry periods, it turns out that the first leads to total financial losses for the energy sector, while the second to payoffs, enabling agreements between Brazil's energy generation and the implementation of environmental flows in the lower stretch of the São Francisco River.Keywords: Environmental allocation of water; Implementation of environmental flows; Financial impact; Reservoir operation; Hydropower generation. RESUMOA alocação ambiental da água consiste em considerar o meio ambiente como lícito usuário da água. A importância em determinar as necessidades hídricas da água para proteção do ecossistema, é reconhecida mundialmente, entretanto as implementações práticas de vazões ambientais são restritas, necessitando da avaliação dos impactos dessa implementação nos demais usuários da água. Nesse contexto, o artigo objetiva avaliar o impacto econômico no setor elétrico considerando as vazões ambientais como restrição de escoamento a jusante dos reservatórios. O estudo de caso é o baixo curso do rio São Francisco, uma região que presenta uma degradação social e ambiental acentuada com extrema relevância para o sistema energético do Brasil. A metodologia adotada compreendeu a construção de cenários de operação de reservatórios, modelagem matemática do sistema hídrico e análise custo-benefício para o setor energético. A simulação aponta a possíveis conflitos entre os usos não consuntivos. Avaliando a análise custo-benefício para períodos normais e secos, os primeiros resultam em perdas financeiras totais para o setor elétrico, enquanto os segundos em ganhos totais, permitindo acordos entre a geração de energia e a implementação de vazões ambientais no baixo curso do rio São Francisco.

show abstract

Operation of a hydropower system considering environmental flow requirements: A case study in La Nga river basin, Vietnam

Cited by 55 publications

References 13 publications

Accounting for environmental flow requirements in global water assessments

Accounting for environmental flow requirements in global water assessments

Portfolio optimisation for hydropower producers that balances riverine ecosystem protection and producer needs

Cost-benefit analysis of reservoir operation scenarios considering environmental flows for the lower stretch of the São Francisco River (Brazil)

Contact Info

Product

Resources

About