Evaluation of instream ecological flow with consideration of ecological responses to hydrological variations in the downstream Hongshui River Basin, China

River ecosystems are characterised by a naturally high level of hydrodynamic perturbations which create aquatic-terrestrial habitats indispensable for many species, as well as for the human beings' welfare. Environmental degradation and habitat loss caused by increasing anthropogenic pressures and global change affect freshwater aquatic ecosystems worldwide and have caused changes in water flow regimes and channels morphologies. These, in turn, decreased the natural flow capacity and reduced habitat availability, thus causing severe degradation of rivers' ecological integrity. The ecological flow (e-flow) is commonly intended as the quantity, timing, duration, frequency and quality of water flows required to sustain freshwater, estuarine and near‐shore ecosystems and the human livelihoods and well‐being. Maintaining the e-flow represents a potential tool for restoring and managing river ecosystems, to preserve the autochthonous living communities, along with environmental services and cultural/societal values. In the last decade, methods for the determination of the e-flow in European rivers moved from a simply hydrological approach towards establishing a linkage between the hydrological regime and the good ecological status (GES) of the water bodies, as identified by the European Water Framework Directive (WFD; 2000/60/EC). Each Member State is required to implement and integrate into the River Basin Management Plans (RBMP) a methodology for the determination of the e-flow, ensuring that rivers can achieve and maintain the GES. The competent river basin authorities have thus to ascertain whether national methodologies to can be applied to different river typologies and basin environment characteristics. In this context, we narratively review the e-flow assessments in the heterogeneous Italian territory, in particular on a water scant region such as Sardinia, by analysing laws, guidelines and focusing on study cases conducted with micro and meso-scale hydraulic-habitat approaches. In the sight of a more ecological-based application of national e-flow policy, we suggest that meso-habitat methods provide a valuable tool to overcome several limitations of current e-flow implementation in the Italian territory. However, to face future challenges, such as climate change adaptation, we stress the need for further experimental studies to update water management plans with greater attention for nature conservation.

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Characteristics and Adaptability Assessment of Commonly Used Ecological Flow Methods in Water Storage and Hydropower Projects, the Case of Chinese River Basins

Water ◽

10.3390/w11102035 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2035

Author(s):

Lejun Ma ◽

Huan Wang ◽

Changjun Qi ◽

Xinnan Zhang ◽

Hanwen Zhang

Keyword(s):

River Basin ◽

Yellow River ◽

Yangtze River Basin ◽

Water Storage ◽

Yellow River Basin ◽

River Basins ◽

Average Flow ◽

Ecological Flow ◽

Tennant Method ◽

Rate Method

The construction and operation of water storage and hydropower projects affects the structure of water ecosystems of downstream rivers, and the establishment of ecological flow in rivers below the water storage and hydropower projects has significant impacts on maintaining the stability of river ecosystems. A database was established based on 2000–2017 environmental impact assessment (EIA) reports on water storage and hydropower projects in China and ecological flow (e-flow) methods, and the three widely used e-flow methods for water storage and hydropower projects in China were identified on the database. Furthermore, an ecological flow satisfaction degree model was used to evaluate the methods using long series of historical hydrological data from the hydrological stations in the Yellow River basin, the Yangtze River basin, and the Liao River basin. The results showed that hydrological methods are the type most often used for water storage and hydropower projects in China, including the Tennant method, the minimum monthly average flow with 90% guarantee rate method (Mm9M method), and the measured historical minimum daily average flow rate method (MDM method). However, the ecological flow methods selected are not significantly different among different basins, indicating that the selection of ecological flow methods is rather arbitrary, and adaptability analysis is not available. The results of the ecological flow satisfaction model showed that the Tennant method is not suitable for large river basins. The results of this study can provide technical support for establishment and management decisions surrounding ecological flow.

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Application of Entropy Method to Quantify Future Ecological Flow in the Yellow River Basin

Entropy ◽

10.3390/e24010072 ◽

2021 ◽

Vol 24 (1) ◽

pp. 72

Author(s):

Xinru Wang ◽

Huijuan Cui

Keyword(s):

Climate Change ◽

River Basin ◽

Yellow River ◽

Yellow River Basin ◽

The Yellow River ◽

Human Beings ◽

Ecological Flow ◽

The Future ◽

The Yellow River Basin ◽

The Impact

Due to both anthropogenic and climate change impacts, precipitation and runoff in the Yellow River basin have decreased in the past 50 years, leading to more pressure in sustaining human beings and ecosystem needs. It is essential to evaluate the flow condition in the Yellow River basin and see whether it may satisfy its ecological flow in the future. Therefore, this study applied an entropy-based method to calculate the flow duration curves from both observed and simulated data to evaluate the impact of climate change on ecological flow in the Yellow River basin. The simulated FDCs from H08 and DBH models show good agreement with each other and fit observation well. Results show that the decadal FDC at each station is generally predicted to be higher or stay in the higher range under both RCP 2.6 and 8.5 scenarios, suggesting an increase in water amount in the future. It is found that the high flows increase much faster than the low flows, resulting in larger slopes than the references ones, which is due to the larger entropy and M values in the future. At most of the stations, the future values of Q95 and Q90 will safely exceed the threshold. It is found that at the Lanzhou, Wubao, Longmen, and Huayuankou stations, there will be no or little threat to future ecological flow. Still, at the Toudaoguai and Sanmanxia stations, the ecological requirement is not always satisfied. The water stress at the Tangnaihai station from the upper stream of the Yellow River may be threatened in the future.

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Water replenishment for ecological flow with E-WAS framework: a case study of the Longgang River Basin, Shenzhen, China

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-383-327-2020 ◽

2020 ◽

Vol 383 ◽

pp. 327-339

Author(s):

Ziqi Yan ◽

Zuhao Zhou ◽

Xuefeng Sang ◽

Hao Wang ◽

Yangwen Jia

Keyword(s):

River Basin ◽

Water Environment ◽

Simulation Framework ◽

Modeling Tools ◽

Rapid Urbanization ◽

Ecological Water Demand ◽

Control Scheme ◽

Ecological Flow ◽

Longgang River Basin

Abstract. With rapid urbanization, there will be more conflict between human systems and the riverine ecological system, and therefore, ecological operations, practices and research must involve the ecological water replenishment of entire river basins with new modeling tools. In this study, we establish an ecological flow-oriented water resource allocation and simulation framework (E-WAS). Virtual reservoirs and ecological units are added to the water resources network. With new water balance equations for virtual reservoirs and ecological units, the E-WAS can simulate the ecological replenishment process in a river basin and can provide a recommended water replenishment scheme that considers optimization principles. The E-WAS was applied in the Longgang River Basin, Shenzhen, China. 17 ecological units and 45 water supply nodes are considered in the model. A water replenishment scheme that used water from 31 reservoirs and reclaimed water from 7 water sewage plants was selected. This scheme significantly increased the satisfactory degree of ecological water demand and efficiently supported the formulation of a control scheme for the water environment of a basin. The E-WAS framework is similar to model plug-ins but helps to avoid the large workload that is required for model redevelopment and can expand the functions of models quickly.

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Study on Calculation Method of Target Ecological Water Amount in Shortage Areas of Mintuo River Basin

E3S Web of Conferences ◽

10.1051/e3sconf/202123303033 ◽

2021 ◽

Vol 233 ◽

pp. 03033

Author(s):

Tang Bing ◽

Li Bo ◽

Wang WenChao

Keyword(s):

Water Quality ◽

River Basin ◽

Calculation Method ◽

Simulation Method ◽

Environmental Capacity ◽

Water Quality Simulation ◽

Complex Concept ◽

Natural Rainfall ◽

Ecological Flow ◽

Development And Utilization

Ecological water replenishment is the part of ecological flow deducting the remaining local existing water that needs to be recharged by other water sources. It has become the basic basis for water resources development and utilization and water affairs coordination. Ecological flow is a complex concept with numerous calculation methods and obvious regional differences. In view of the characteristics of the Mintuo River Basin, especially the problem that the extensive economic development exceeds the environmental carrying capacity of the river, considering the lack of natural rainfall, this paper recommends a one-dimensional water quality simulation method that maintains environmental capacity. Taking Jingyan County as a representative, a case study was carried out. The river was divided into several sections according to the water function zoning, and the water quality of each section was simulated to determine the section and the total river water replenishment, and through compared with the traditional calculation method of water conservancy planning, the rationality and benefit of the period are analyzed.

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Study on Countermeasures System of Ecological Flow Guarantee in Weihe River Basin

10.5194/egusphere-egu2020-3215 ◽

2020 ◽

Author(s):

Xinhai Zhang

Keyword(s):

Water Resources ◽

River Basin ◽

Cross Sections ◽

Warning System ◽

Base Flow ◽

Water Withdrawal ◽

Current Status ◽

Ecological Flow ◽

Weihe River ◽

Weihe River Basin

Ensuring the ecological flow of the Weihe River is a basic requirement for strengthening water resources management and ecological protection and restoration in Weihe River Basin and is of great significance for ensuring the safety of water resources and ecological safety in Weihe River Basin. This study selects three major control cross-sections of Beidao, Linjiacun, and Huaxian for ecological flow protection research. In this paper, the existing results of the main control cross-sections were summarized, the Tennant method and the most withered month average flow method were applied to analyze and calculate the ecological base flow. Then, the flow data from 1980 to 2016 are applied to analyze the degree of ecological flow guarantee. Based on the changes in the Weihe River runoff and the development of water resources, the rationality and accessibility of the ecological flow were demonstrated, and the ecological base flow indicators of Beidao, Linjiacun and Huaxian cross-sections were comprehensively determined to be 2m3/s, 5m3/s, and 12m3/s, respectively. Furthermore, the current status of ecological security in the Weihe River Basin was analyzed in depth. It is clear that there were problems in the Weihe River Basin, such as strong water demand, the high pressure of water uses for life, production and ecology during dry years, difficult guarantee of ecological flow, incomplete ecological flow guarantee working mechanism, etc. Based on the analysis, the suggestions were proposed from the perspectives of enhancing the organization and leadership, intensifying the unified allocation of water resources in the Weihe River, strengthening the capacity of water regime monitoring, establishing an early warning system for ecological flow, strictly controlling water withdrawal, and reinforcing supervision and assessment. Then the countermeasure system of ecological flow guarantee was established.

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Variation in ecological flow regimes and their response to dams in the upper Yellow River basin

Environmental Earth Sciences ◽

10.1007/s12665-016-5751-x ◽

2016 ◽

Vol 75 (11) ◽

Cited By ~ 8

Author(s):

Hongbo Zhang ◽

Vijay P. Singh ◽

Qiang Zhang ◽

Lei Gu ◽

Wenbo Sun

Keyword(s):

River Basin ◽

Yellow River ◽

Flow Regimes ◽

Yellow River Basin ◽

Ecological Flow ◽

Upper Yellow River ◽

Ecological Flow Regimes

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Ecological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States

Ecohydrology ◽

10.1002/eco.1460 ◽

2013 ◽

Vol 7 (5) ◽

pp. 1262-1280 ◽

Cited By ~ 23

Author(s):

Rodney R. Knight ◽

Jennifer C. Murphy ◽

William J. Wolfe ◽

Charles F. Saylor ◽

Amy K. Wales

Keyword(s):

United States ◽

Flow Regime ◽

River Basin ◽

Fish Community ◽

Community Response ◽

Tennessee River ◽

Ecological Flow

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STUDY ON METHODS OF DETERMINATION OF AN ECOLOGICAL FLOW FOR THE MANAGEMENT OF WATER RESOURCES OF THE RIVER BASIN ON MARACAÇUMÉ RIVER

Periódico Tchê Química ◽

10.52571/ptq.v15.n30.2018.30_periodico30_pgs_27_34.pdf ◽

2018 ◽

Vol 15 (30) ◽

pp. 27-34

Author(s):

L. S. ROSA JUNIOR ◽

H. S. ALMEIDA ◽

S. C. S. A. BRASIL ◽

A. B. P. DE MORAIS ◽

J. B. SARAIVA ◽

...

Keyword(s):

Water Resources ◽

River Basin ◽

Water Availability ◽

Sustainable Management ◽

Flow Regimes ◽

Maximum Percentage ◽

Ecological Flow ◽

Tennant Method

The elaboration of a study on methods for the determination of ecological flow for the management of the water resources of the Maracaçumé River Basin is very important for the proposed use and conservation of these resources insofar as the uses of water, especially the advisory uses, have changed the flow regimes and the existing water availability. In this context, this work aims to discuss about the applicability of hydrological methods that help in the correct and sustainable management of the water resources. In this way, were applied theQ7,10 Method; the 90% and 95% Method, beyond the Tennant Method with ecological flow corresponding to 30% of the average annual flow. The main results obtained were the characterization of the Maracaçumé River Basin and the flow values obtained in each method (0.541 m3/s, 1,075 m3/s, 0,459 m3/s and 19,50 m3/s for the Q7,10; Q90%; Q95% and Tennant (30%) methods, respectively). The work indicates that for the management of water resources in the Maracaçumé river basin, the ecological flow obtained through the Q90 methodology should continue to be adopted, evaluating the possibility of adapting the maximum percentage of use.

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