Huangpu River is about 114.5 km from upriver Dianfeng to downriver Wusong, near the estuary of the Yangtze River. It plays a key role in supplying water for production, life, shipment and irrigation. With the industri...Huangpu River is about 114.5 km from upriver Dianfeng to downriver Wusong, near the estuary of the Yangtze River. It plays a key role in supplying water for production, life, shipment and irrigation. With the industrial development, the pollution of the Huangpu River has become serious recently. The biological oxygen demand （BOD）, total nitrogen （TN）, total phosphorus （TP）, oil, phenol and suspended solids （SS） were lower in the upstream sites than in the downstream sites, indicating pollutants being input along its course. Water quality was the worst in the Yangpu site, near the center of Shanghai City. Dissolved oxygen （DO） content was less than 2 mg/L in the site of Yangpu in July. Among relations between thirteen characteristics, relations between BOD, DO, TN, TP, NH4^＋ -N, NO3^- -N and the count of total bacteria or Escherichia coli were significant and interdependent. Inner relationships between these main characteristics in the Huangpu River were studied. High nutrient concentration led to growth of microorganisms, including E. coli. Degradation of organic matters and respiration of bacteria made oxygen concentration decreased in the water body, and DO was a key factor for nitrification-denitrification process of nitrogen. In the Yangpu site, DO was decreased to less than 3.0 mg/L with BOD higher than 7.5 mg/L in May and July. Low DO concentration will decrease nitrification rate. Nitrification need at higher DO value than other organic substrate oxidation. Consequently, river water contains low NO3^- -N values with high amounts of TN and NH4^＋ -N there. This will block the self-purification of surface water, by decreasing the rate of nitrification-denitrification transformation process in the water body.展开更多
Interconnected river system networks is a national water conservancy strategy in China and focus of research. Here we discuss the classification system, material and energy exchange between rivers and lakes, various d...Interconnected river system networks is a national water conservancy strategy in China and focus of research. Here we discuss the classification system, material and energy exchange between rivers and lakes, various dynamic flows and ecological functions of river-lake interconnected relationships. We then propose a novel method for the health assessment of river systems based on interconnected water system networks. In a healthy river system there is ＂material and energy exchange＂ and it is the first and foremost relationship of material and energy exchange between rivers and lakes. There are unobstructed various ＂flows＂ between rivers and lakes including material flows （water, dissolved substances, sediments, organisms and contaminants）, energy flows （water levels, flow and flow velocity）, information flows （information generated with water flows, organisms and human activities） and value flows （shipping, power generation, drinking and irrigation）. Under the influences of na- ture and human activity, various flows are connected by river-lake interconnection to carry material and energy exchange between rivers and lakes to achieve river-lake interactions. The material and energy exchange between rivers and lakes become one of the approaches and the direct driving forces of changes in river-lake interconnected relationships. The benignant changes in river-lake interconnected relationship tend to be in relatively steady state and in ideal dynamic balance.展开更多
River managers in Australia are managing in the face of extremes to provide security of water supply for people, production and the environment. Balancing the water requirements of people, environments and econo- mies...River managers in Australia are managing in the face of extremes to provide security of water supply for people, production and the environment. Balancing the water requirements of people, environments and econo- mies requires that water security is viewed holistically, not just in terms of the water available for human consump- tion. Common definitions of water security focus on the needs of both humans and ecosystems for purposes such as drinking, agriculture and industrial use, and to maintain ecological values. Information about achieving water security for the environment or ecological purposes can be a challenge to interpret because the watering require- ments of key ecological processes or assets are not well understood, and the links between ecological and human values are often not obvious to water users. Yet the concepts surrounding river health are inherently linked to holistic concepts of water security. The measurement of aquatic biota provides a valuable tool for managers to understand progress toward achieving ecological water security objectives. This paper provides a comprehensive review of the reference condition approach to river health assessment, using the development of the Australian River Assessment System （AUSRIVAS） as a case study. We make the link between the biological assessment of river health and assessment of ecological water security, and suggest that such an approach provides a way of reporting that is relevant to the contribution made by ecosystems to water security. The reference condition approach, which is the condition representative of minimally disturbed sites organized by selected physical, chemical, and biological characteristics, is most important for assessing ecological water security objectives.展开更多
Background The application of index of biotic integrity(IBI)to evaluate river health can be an essential method for river ecosystem management.However,these types of methods were developed in small,low-order streams,a...Background The application of index of biotic integrity(IBI)to evaluate river health can be an essential method for river ecosystem management.However,these types of methods were developed in small,low-order streams,and are therefore,infrequently applied to large rivers.To that end,phytoplankton communities and environmental variables were monitored in 30 sampling segments of the middle and lower reaches of the Yangtze River,China during the wet(July-August)and dry(November-December)seasons in 2017-2018.We developed a phytoplankton-based index of biotic integrity(P-IBI)and used the index to assess the ecological health of the Yangtze River.Relationships among P-IBI,its component metrics,and environmental factors were analyzed across different seasons.Results Results obtained from the P-IBI indicated that the phytoplankton-based ecological health of the Yangtze River was rated as“good”during both seasons,with an overall better condition in the dry season.During the wet season,there were scattered river segments with P-IBI ratings of“fair”or below.Water quality and land use appeared to shape the patterns of P-IBI.In the wet season,P-IBI negatively correlated with total phosphorus,nitrate,total suspended solids,turbidity,conductivity,and dissolved oxygen.In the dry season,P-IBI positively correlated with total nitrogen,ammonium,and nitrite,and negatively correlated with water temperature.Conclusions The ecological health of the Yangtze River as reflected by the P-IBI exhibited spatial and temporal variability,with the effect of water quality being greater than that of local land use.This study indicated the importance of considering seasonal effects in detecting large river ecological health.These findings enhanced our understanding of the ecological health and characterized potential benchmarks for management of the Yangtze River.These findings also may be applicable to other large rivers elsewhere.展开更多
基金Propject supported by the Special Environmental Protection Development Foundation of Shanghai,China (No.00980014).
文摘Huangpu River is about 114.5 km from upriver Dianfeng to downriver Wusong, near the estuary of the Yangtze River. It plays a key role in supplying water for production, life, shipment and irrigation. With the industrial development, the pollution of the Huangpu River has become serious recently. The biological oxygen demand （BOD）, total nitrogen （TN）, total phosphorus （TP）, oil, phenol and suspended solids （SS） were lower in the upstream sites than in the downstream sites, indicating pollutants being input along its course. Water quality was the worst in the Yangpu site, near the center of Shanghai City. Dissolved oxygen （DO） content was less than 2 mg/L in the site of Yangpu in July. Among relations between thirteen characteristics, relations between BOD, DO, TN, TP, NH4^＋ -N, NO3^- -N and the count of total bacteria or Escherichia coli were significant and interdependent. Inner relationships between these main characteristics in the Huangpu River were studied. High nutrient concentration led to growth of microorganisms, including E. coli. Degradation of organic matters and respiration of bacteria made oxygen concentration decreased in the water body, and DO was a key factor for nitrification-denitrification process of nitrogen. In the Yangpu site, DO was decreased to less than 3.0 mg/L with BOD higher than 7.5 mg/L in May and July. Low DO concentration will decrease nitrification rate. Nitrification need at higher DO value than other organic substrate oxidation. Consequently, river water contains low NO3^- -N values with high amounts of TN and NH4^＋ -N there. This will block the self-purification of surface water, by decreasing the rate of nitrification-denitrification transformation process in the water body.
基金National Natural Science Foundation of China(41361003)Science and Technology Project in Jiangxi Province Department of Education(GJJ14733)
文摘Interconnected river system networks is a national water conservancy strategy in China and focus of research. Here we discuss the classification system, material and energy exchange between rivers and lakes, various dynamic flows and ecological functions of river-lake interconnected relationships. We then propose a novel method for the health assessment of river systems based on interconnected water system networks. In a healthy river system there is ＂material and energy exchange＂ and it is the first and foremost relationship of material and energy exchange between rivers and lakes. There are unobstructed various ＂flows＂ between rivers and lakes including material flows （water, dissolved substances, sediments, organisms and contaminants）, energy flows （water levels, flow and flow velocity）, information flows （information generated with water flows, organisms and human activities） and value flows （shipping, power generation, drinking and irrigation）. Under the influences of na- ture and human activity, various flows are connected by river-lake interconnection to carry material and energy exchange between rivers and lakes to achieve river-lake interactions. The material and energy exchange between rivers and lakes become one of the approaches and the direct driving forces of changes in river-lake interconnected relationships. The benignant changes in river-lake interconnected relationship tend to be in relatively steady state and in ideal dynamic balance.
文摘River managers in Australia are managing in the face of extremes to provide security of water supply for people, production and the environment. Balancing the water requirements of people, environments and econo- mies requires that water security is viewed holistically, not just in terms of the water available for human consump- tion. Common definitions of water security focus on the needs of both humans and ecosystems for purposes such as drinking, agriculture and industrial use, and to maintain ecological values. Information about achieving water security for the environment or ecological purposes can be a challenge to interpret because the watering require- ments of key ecological processes or assets are not well understood, and the links between ecological and human values are often not obvious to water users. Yet the concepts surrounding river health are inherently linked to holistic concepts of water security. The measurement of aquatic biota provides a valuable tool for managers to understand progress toward achieving ecological water security objectives. This paper provides a comprehensive review of the reference condition approach to river health assessment, using the development of the Australian River Assessment System （AUSRIVAS） as a case study. We make the link between the biological assessment of river health and assessment of ecological water security, and suggest that such an approach provides a way of reporting that is relevant to the contribution made by ecosystems to water security. The reference condition approach, which is the condition representative of minimally disturbed sites organized by selected physical, chemical, and biological characteristics, is most important for assessing ecological water security objectives.
基金supported by National Key R&D Program of China(2019YFD0901203)Chinese Academy of Sciences(ZDRW-ZS-2017-3-2).
文摘Background The application of index of biotic integrity(IBI)to evaluate river health can be an essential method for river ecosystem management.However,these types of methods were developed in small,low-order streams,and are therefore,infrequently applied to large rivers.To that end,phytoplankton communities and environmental variables were monitored in 30 sampling segments of the middle and lower reaches of the Yangtze River,China during the wet(July-August)and dry(November-December)seasons in 2017-2018.We developed a phytoplankton-based index of biotic integrity(P-IBI)and used the index to assess the ecological health of the Yangtze River.Relationships among P-IBI,its component metrics,and environmental factors were analyzed across different seasons.Results Results obtained from the P-IBI indicated that the phytoplankton-based ecological health of the Yangtze River was rated as“good”during both seasons,with an overall better condition in the dry season.During the wet season,there were scattered river segments with P-IBI ratings of“fair”or below.Water quality and land use appeared to shape the patterns of P-IBI.In the wet season,P-IBI negatively correlated with total phosphorus,nitrate,total suspended solids,turbidity,conductivity,and dissolved oxygen.In the dry season,P-IBI positively correlated with total nitrogen,ammonium,and nitrite,and negatively correlated with water temperature.Conclusions The ecological health of the Yangtze River as reflected by the P-IBI exhibited spatial and temporal variability,with the effect of water quality being greater than that of local land use.This study indicated the importance of considering seasonal effects in detecting large river ecological health.These findings enhanced our understanding of the ecological health and characterized potential benchmarks for management of the Yangtze River.These findings also may be applicable to other large rivers elsewhere.
