The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Jinxi Song - One of the best experts on this subject based on the ideXlab platform.
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Instream Flow requirements for sediment transport in the lower weihe river
Hydrological Processes, 2010Co-Authors: Jinxi Song, Yanghe HuiAbstract:Estimation of Instream Flow requirements for sediment transport (IFRST) in the downstream Weihe River is important for the maintenance of a healthy ecosystem of the river. In this study, the IFRST for the lower Weihe River is estimated on the basis of the observed hydrological data during the period 1960–2001. The results showed that the mean annual IFRSTs for the reach between Lintong and Huaxian and the reach below Huaxian were 6·85 and 7·62 billion m3/year, respectively, and the standard errors were 0·50 and 0·76 billion m3/year, respectively. The results also showed that the Sanmenxia Reservoir is an important driver for the changes in channel morphology and hydraulics, as well as the IFRST. Furthermore, according to the hydrological frequency (p value) estimated from annual Instream Flow data during the period 1960–2001, four typical years (p = 25%, 50%, 75% and 90%) for the two reaches of the Weihe River were determined. The analysis showed that the IFRST has a negative power functional relationship with the sediment concentration. On the basis of the efficiency coefficients (R2) during three sub-periods 1960–1973, 1974–1990 and 1991–2001, the annual IFRSTs in the above two reaches for the four typical years were estimated under different deposition and erosion–deposition conditions. The results provide useful references for restoration and water resource management of the Weihe River. Copyright © 2010 John Wiley & Sons, Ltd.
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Ecological and environmental Instream Flow requirements for the Wei River—the largest tributary of the Yellow River
Hydrological Processes, 2007Co-Authors: Jinxi Song, Chao LiuAbstract:Instream Flows are essential determinants of channel morphology, riparian and aquatic flora and fauna, water quality estuarine inFlow and stream load transport. The ecological and environmental Instream Flow requirements (EEIFR) should be estimated to make the exploitation and utilization of water resources in a highly efficient and sustainable way and maintain the river ecosystem good health. As the largest tributary of the Yellow River, the Wei River is the ‘Mother River’ of Guanzhong region in Shaanxi province. It plays a great role in the development of West China and the health of the ecosystem of the Yellow River. The objective of this study is to estimate the EEIFR for improving the Wei River's ecological and environmental condition and develop the river healthily. Concerning the main ecological and environmental functions of the Wei River in Shaanxi Province, the EEIFR for each section of the Wei River including minimum Instream Flow requirements (IFR) for aquicolous biotopes maintenance, IFR for channel seepage, channel evaporation, stream self-purification and sediment transportation were estimated in this paper. The methods to estimate the Instream Flow requirements for stream self-purification and Instream Flow requirements for sediment transportation were proposed. The temporal scale of typical years include the year with the probability 25% of occurrence (high-Flow year), the year with the probability 50% (normal-Flow year) and the year with the probability 75% (low-Flow year). The results show that the EEIFR for the Wei River mainly include Instream Flow requirements for self-purification and sediment transportation in each typical year. From high-Flow year to low-Flow year, the annual EEIFR for each reach decrease, except those for the reach from Linjiacun to Weijiabao, and from Linjiacun at the upper reaches to Huaxian at the lower reaches, and the annual reach EEIFR decrease in a sequence. Copyright © 2007 John Wiley & Sons, Ltd.
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ecological and environmental Instream Flow requirements for the wei river the largest tributary of the yellow river
Hydrological Processes, 2007Co-Authors: Jinxi Song, Chunlei LiuAbstract:Instream Flows are essential determinants of channel morphology, riparian and aquatic flora and fauna, water quality estuarine inFlow and stream load transport. The ecological and environmental Instream Flow requirements (EEIFR) should be estimated to make the exploitation and utilization of water resources in a highly efficient and sustainable way and maintain the river ecosystem good health. As the largest tributary of the Yellow River, the Wei River is the ‘Mother River’ of Guanzhong region in Shaanxi province. It plays a great role in the development of West China and the health of the ecosystem of the Yellow River. The objective of this study is to estimate the EEIFR for improving the Wei River's ecological and environmental condition and develop the river healthily. Concerning the main ecological and environmental functions of the Wei River in Shaanxi Province, the EEIFR for each section of the Wei River including minimum Instream Flow requirements (IFR) for aquicolous biotopes maintenance, IFR for channel seepage, channel evaporation, stream self-purification and sediment transportation were estimated in this paper. The methods to estimate the Instream Flow requirements for stream self-purification and Instream Flow requirements for sediment transportation were proposed. The temporal scale of typical years include the year with the probability 25% of occurrence (high-Flow year), the year with the probability 50% (normal-Flow year) and the year with the probability 75% (low-Flow year). The results show that the EEIFR for the Wei River mainly include Instream Flow requirements for self-purification and sediment transportation in each typical year. From high-Flow year to low-Flow year, the annual EEIFR for each reach decrease, except those for the reach from Linjiacun to Weijiabao, and from Linjiacun at the upper reaches to Huaxian at the lower reaches, and the annual reach EEIFR decrease in a sequence. Copyright © 2007 John Wiley & Sons, Ltd.
Qiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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Nonstationary Ecological Instream Flow and Relevant Causes in the Huai River Basin, China
Water, 2021Co-Authors: Qingzhi Wen, Peng Sun, Qiang ZhangAbstract:Based on the daily precipitation data during 1960–2016 at 72 stations and the daily streamFlow data during 1956–2016 at 7 hydrological stations in the Huai River Basin (HRB), China, eco-surplus and eco-deficit under influences of abrupt streamFlow behaviors were analyzed using Flow Duration Curve (FDC). The relations between indicators of hydrological alteration (IHA) and ecological indicators (Shannon Index, SI) were quantified, investigating impacts of altered hydrological processes on the evaluations of the ecological Instream Flow. Besides, we also quantified fractional contributions of climatic indices to nonstationary ecological Instream Flow using the Generalized Additive Models for Location Scale and Shape (GAMLSS) framework. While the possible impact of human activities on ecological Instream Flow will be revealed based on land use changes data. The results indicated that: (1) FDC is subject to general decrease due to hydrological alterations, and most streamFlow components are lower than 25% FDC. We found increased eco-deficit and decreased eco-surplus due to altered hydrological processes. The FDC of the streamFlow in the main stream of the HRB is lower than that along the tributaries of the HRB. Eco-surplus (eco-deficit) changes are in good line with precipitation anomaly changes during the Spring, Autumn and Winter periods. However, the hydrological alterations due to hydrological regulations by the reservoirs are the primary cause behind the mismatch between ecological Instream Flow and precipitation anomalies during summer; (2) Annual and seasonal eco-surplus (eco-deficit) is decreasing (increasing) and that during winter season is an exception. Although higher eco-surplus in winter than in other seasons, the eco-surplus is decreasing persistently and the 21st century witnessed the lowest eco-surplus along the main stream of the HRB. Meanwhile, the Shannon index indicated decreased ecological diversity across the HRB; (3) The ecological Instream Flow is highly sensitive to The Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO) and Nino 3.4 Sea Surface Temperature Index (Nino3.4). Meanwhile, the ecological Instream Flow along the maInstream of the HRB is highly sensitive to climate indices. While the ecological Instream Flow by GAMLSS model has better fitting performance in describing the extreme values and local trends.
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evaluation of ecological Instream Flow considering hydrological alterations in the yellow river basin china
Global and Planetary Change, 2018Co-Authors: Qiang Zhang, Zongjiao Zhang, Peijun Shi, Vijay P SinghAbstract:Abstract The Yellow River is the second largest river in China and is the important source for water supply in the northwestern and northern China. It is often regarded as the mother river of China. Owing to climatic change and intensifying human activities, such as increasing withdrawal of water for meeting growing agricultural irrigation needs since 1986, the Flow of Yellow River has decreased, with serious impacts on the ecological environment. Using multiple hydrological indicators and Flow Duration Curve (DFC)-based ecodeficit and ecosurplus, this study investigates the impact of hydrological alterations, such as the impact of water reservoirs or dams, on downstream ecological Instream Flow. Results indicate that: (1) due to the impoundment and hydrological regulations of water reservoirs, occurrence rates and magnitudes of high Flow regimes have decreased and the decrease is also found in the magnitudes of low Flow events. These changes tend to be more evident from the upper to the lower Yellow River basin; (2) human activities tend to enhance the Instream Flow variability, particularly after the 1980s;(3) the ecological environment in different parts of the Yellow River basin is under different degrees of ecological risk. In general, lower to higher ecological risk can be detected due to hydrological alterations from the upper to the lower Yellow River basin. This shows that conservation of ecological environment and river health is facing a serious challenge in the lower Yellow River basin; (4) ecological Instream Flow indices, such as ecodeficit and ecosurplus, and IHA32 hydrological indicators are in strong relationships, suggesting that ecodeficit and ecosurplus can be regarded as appropriate ecological indicators for developing measures for mitigating the adverse impact of human activities on the conservation of ecological environment in the Yellow River basin.
Vijay P Singh - One of the best experts on this subject based on the ideXlab platform.
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evaluation of ecological Instream Flow considering hydrological alterations in the yellow river basin china
Global and Planetary Change, 2018Co-Authors: Qiang Zhang, Zongjiao Zhang, Peijun Shi, Vijay P SinghAbstract:Abstract The Yellow River is the second largest river in China and is the important source for water supply in the northwestern and northern China. It is often regarded as the mother river of China. Owing to climatic change and intensifying human activities, such as increasing withdrawal of water for meeting growing agricultural irrigation needs since 1986, the Flow of Yellow River has decreased, with serious impacts on the ecological environment. Using multiple hydrological indicators and Flow Duration Curve (DFC)-based ecodeficit and ecosurplus, this study investigates the impact of hydrological alterations, such as the impact of water reservoirs or dams, on downstream ecological Instream Flow. Results indicate that: (1) due to the impoundment and hydrological regulations of water reservoirs, occurrence rates and magnitudes of high Flow regimes have decreased and the decrease is also found in the magnitudes of low Flow events. These changes tend to be more evident from the upper to the lower Yellow River basin; (2) human activities tend to enhance the Instream Flow variability, particularly after the 1980s;(3) the ecological environment in different parts of the Yellow River basin is under different degrees of ecological risk. In general, lower to higher ecological risk can be detected due to hydrological alterations from the upper to the lower Yellow River basin. This shows that conservation of ecological environment and river health is facing a serious challenge in the lower Yellow River basin; (4) ecological Instream Flow indices, such as ecodeficit and ecosurplus, and IHA32 hydrological indicators are in strong relationships, suggesting that ecodeficit and ecosurplus can be regarded as appropriate ecological indicators for developing measures for mitigating the adverse impact of human activities on the conservation of ecological environment in the Yellow River basin.
Xi-qin Wang - One of the best experts on this subject based on the ideXlab platform.
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Methodology to determine regional water demand for Instream Flow and its application in the Yellow River Basin.
Journal of environmental sciences (China), 2006Co-Authors: Yuan Zhang, Zhifeng Yang, Xi-qin WangAbstract:Abstract In order to realistically reflect the difference between regional water demand for Instream Flow and river ecological water demand as well as to resolve the problem that water demand may be counted repeatedly, a concept of regional water demand for minimum Instream Flow have been developed. The concept was used in the process of determining river functions and calculating ecological water demand for a river. The Yellow River watershed was used to validate the calculation methodology for regional water demand. Calculation results indicate that there are significant differences in water demands among the different regions. The regional water demand at the downstream of the Yellow River is the largest about 14.893 × 10 9 m 3 /a. The regional water demand of upstream, Lanzhou-Hekou section is the smallest about −5.012 × 10 9 m 3 /a. The total ecological water demand of the Yellow River Basin is 23.06 × 10 9 m 3 /a, about the 39% of surface water resources of the Yellow River Basin. That means the maximum available surface water resources should not exceed 61% in the Yellow River Basin. The regional river ecological water demands at the Lower Section of the Yellow River and Longyangxia-Lanzhou Section exceed the surface water resources produced in its region and need to be supplemented from other regions through the water rational planning of watershed water resources. These results provides technical basis for rational plan of water resources of the Yellow River Basin.
Chao Liu - One of the best experts on this subject based on the ideXlab platform.
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Ecological and environmental Instream Flow requirements for the Wei River—the largest tributary of the Yellow River
Hydrological Processes, 2007Co-Authors: Jinxi Song, Chao LiuAbstract:Instream Flows are essential determinants of channel morphology, riparian and aquatic flora and fauna, water quality estuarine inFlow and stream load transport. The ecological and environmental Instream Flow requirements (EEIFR) should be estimated to make the exploitation and utilization of water resources in a highly efficient and sustainable way and maintain the river ecosystem good health. As the largest tributary of the Yellow River, the Wei River is the ‘Mother River’ of Guanzhong region in Shaanxi province. It plays a great role in the development of West China and the health of the ecosystem of the Yellow River. The objective of this study is to estimate the EEIFR for improving the Wei River's ecological and environmental condition and develop the river healthily. Concerning the main ecological and environmental functions of the Wei River in Shaanxi Province, the EEIFR for each section of the Wei River including minimum Instream Flow requirements (IFR) for aquicolous biotopes maintenance, IFR for channel seepage, channel evaporation, stream self-purification and sediment transportation were estimated in this paper. The methods to estimate the Instream Flow requirements for stream self-purification and Instream Flow requirements for sediment transportation were proposed. The temporal scale of typical years include the year with the probability 25% of occurrence (high-Flow year), the year with the probability 50% (normal-Flow year) and the year with the probability 75% (low-Flow year). The results show that the EEIFR for the Wei River mainly include Instream Flow requirements for self-purification and sediment transportation in each typical year. From high-Flow year to low-Flow year, the annual EEIFR for each reach decrease, except those for the reach from Linjiacun to Weijiabao, and from Linjiacun at the upper reaches to Huaxian at the lower reaches, and the annual reach EEIFR decrease in a sequence. Copyright © 2007 John Wiley & Sons, Ltd.