Dam construction is an important engineering measure in dealing with the relationship between water and human being. However, with dam construction, some disadvantages to the river basin may be caused, including flow ...Dam construction is an important engineering measure in dealing with the relationship between water and human being. However, with dam construction, some disadvantages to the river basin may be caused, including flow flux of downstream changed, flooded area reduced, river species and other organisms changed and substance sedimentation. Furthermore, it brings some diseases to human being and human residential areas reduced too. Based on the basic principles of ecohydralic engineering, some countermeasures to minimize the negative effects on rivers were put forward. They are reservoir ecological regulation, ecohydraulic engineering construction and comprehensive water pollution treatment.展开更多
This paper analyzes the impact of human activities on river ecosystems from two aspects of agricultural production and watershed water conservancy project construction. Among them, dambased water conservancy projects ...This paper analyzes the impact of human activities on river ecosystems from two aspects of agricultural production and watershed water conservancy project construction. Among them, dambased water conservancy projects have caused runoff patterns and artificial segmentation of rivers, which has seriously damaged the energy and material of river corridors as well as the capacity of species to transport the passage. Modern agricultural production not only uses a lot of pesticides and chemical fertilizers, but also occupies a large number of terraces and floodplains, directly leading to the emergence of non-point source pollution. Sometimes the runoff characteristics of the city will also be changed, so the ecological value of the rivers in the city is seriously damaged under such circumstances.展开更多
Tropical river ecosystems are increasingly vulnerable to anthropogenic pressures,yet conventional monitoring methods remain inadequate to capture the rapid and complex ecological changes needed for effective conservat...Tropical river ecosystems are increasingly vulnerable to anthropogenic pressures,yet conventional monitoring methods remain inadequate to capture the rapid and complex ecological changes needed for effective conservation.This study presents“Smart River Watch,”a low-cost,IoT-based ecological monitoring system designed for real-time assessment of key water quality parameters—temperature,pH,and turbidity—in tropical river environments.The system combines Arduino Mega microcontrollers and high-precision sensors with ESP32 WiFi for continuous data transmission to cloud and mobile platforms.Field deployment across five ecologically distinct sites along Indonesia’s Martapura River demonstrated strong performance,achieving exceptional accuracy(r>0.99;error<2%)compared to laboratory methods,a 98.7%transmission success rate,and 23.4-hour operational autonomy.The innovation of this research lies in bridging technological accessibility with ecological needs:enabling high-frequency,real-time monitoring that supports early pollution detection,enhances ecological insight,and empowers local communities through user-friendly mobile interfaces.The cost-effectiveness,rapid deployment(15 minutes per site),and community-based usability of the system make it a scalable solution for biodiversity protection and adaptive water resource management in developing regions.These findings highlight a paradigm shift in ecological monitoring—merging digital innovation with ecosystem stewardship to better protect freshwater biodiversity in the face of accelerating environmental change.展开更多
Starting in the 1960s,a great deal of effort and capital was invested in an endeavor to significantlyimprove the quality of surface water around the United States,particularly in metropolises like New YorkCity,New Yor...Starting in the 1960s,a great deal of effort and capital was invested in an endeavor to significantlyimprove the quality of surface water around the United States,particularly in metropolises like New YorkCity,New York.The Hudson River has been at the forefront of these efforts and has benefited immenselyfrom this campaign.In parts of the developing world,such as China,similar efforts are beginning to gatherthe same type of momentum.Within the past decade,the Huangpu River,which flows through Shanghaiinto the Yangtze Estuary of China,has been a target for ecological restoration and management.It is possibleto draw parallels between the cleanup efforts involved in improving the environmental conditions of theHuangpu and Hudson Rivers.Using the methodologies of series comparison(SCM),water quality index(WQI)modeling,consideration of ecological engineering,and policy strategy design,we comparativelystudied the topography,functions,environmental conditions,ecological engineering countermeasures,andmanagement policies of the two rivers to assist future forecasting of ecological restoration efforts in China.展开更多
Traditional river health assessment relies on limited water quality indices and representative organism activity,but does not comprehensively obtain biotic and abiotic information of the ecosystem.Here,we propose a ne...Traditional river health assessment relies on limited water quality indices and representative organism activity,but does not comprehensively obtain biotic and abiotic information of the ecosystem.Here,we propose a new approach to evaluate the ecological and health risks of river aquatic ecosystems.First,detailed physicochemical and biological characterization of a river ecosystem can be obtained through pollutant determination(especially emerging pollutants)and DNA/RNA sequencing.Second,supervised machine learning can be applied to perform classification analysis of characterization data and ascertain river ecosystem ecology and health.Our proposed methodology transforms river ecosystem health assessment and can be applied in river management.展开更多
River ecosystems face challenges due to environmental degradation and alterations in flow and sediment transport resulting from climate change and other anthropogenic impacts.These changes may substantially affect riv...River ecosystems face challenges due to environmental degradation and alterations in flow and sediment transport resulting from climate change and other anthropogenic impacts.These changes may substantially affect river morphology,nutrient dynamics,wetland vegetation,aquatic habitats,and river ecological stability.This highlights the urgent need for systematic and quantitative studies on the interactions and feedback between changes in flow,sediment transport,and river ecology.In this study,we reviewed flow and sediment transport changes in major Chinese rivers,along with their resulting ecological impacts.We propose conducting eco-fluvial dynamic studies,a potential solution that can guide the evaluation and restoration of ecological health impacted by physical processes.These studies can provide major benefits in balancing human and environmental needs in large river systems,which is crucial for the healthy and sustainable development of rivers.展开更多
By using the concept of emergy and method of emergy analysis, this paper has studied two mountain settlement (village) ecosystems in two aspects: input and output of energy in the agro-systems and the use of fuel ener...By using the concept of emergy and method of emergy analysis, this paper has studied two mountain settlement (village) ecosystems in two aspects: input and output of energy in the agro-systems and the use of fuel energy. The result reveals that the settlement agro-system in the valley of Minjiang River is better in both structure and function than that at the so-called half-high mountain. The former one is higher than the latter one regarding such indices as emergy yield ratio, labor productivity of emergy and emergy sustainable index, but lower than the latter one regarding environmental loading ratio. In terms of fuel emergy, the settlement in the valley enjoys more diversified sources and is less depending on bio-energy while the settlement at the half-high mountain has only one source (i. e. fuel wood) , much depending on bio-energy, may exert a greater pressure on environment.展开更多
Rapid population growth and artificial oasis enlargement did pose great threat to the natural riparian ecosystems of Tarim River and caused seriously ecological deterioration and greater desertification of the Tarim R...Rapid population growth and artificial oasis enlargement did pose great threat to the natural riparian ecosystems of Tarim River and caused seriously ecological deterioration and greater desertification of the Tarim River Basin in the second half of 20 century. Restoration of the endangered riparian ecosystem requires that environmental flow should be restored through restricted and uncontrolled flow diversion irrigation in tributary areas. Implementation of such restriction needs further the basin-wide reallocation of water resources through a set of engineering and non-engineering measures taken to ensure the water requirement in the tributary and maintain effective flows in Tarim River. As one of evolving HELP (Hydrology for Environment, Life and Policy) basins, the article first presents an overview of hydrology, socio-economic development and ecosystem evolution of the Tarim River Basin. Then, those measures for restoring and maintaining environmental flow are reviewed and analyzed along with its applicability and validity. The issues emerging in implementing those measures are also explored, and then the conclusions were summarized. Lessons learned could provide a good example for other basins under similar conditions.展开更多
Using a three-dimensional coupled biophysical model,we simulated the responses of a lowtrophic ecosystem in the East China Sea(ECS)to long-term changes in nutrient load from the Changjiang(Yangtze)River over the perio...Using a three-dimensional coupled biophysical model,we simulated the responses of a lowtrophic ecosystem in the East China Sea(ECS)to long-term changes in nutrient load from the Changjiang(Yangtze)River over the period of 1960–2005.Two major factors aff ected changes in nutrient load:changes in river discharge and the concentration of nutrients in the river water.Increasing or decreasing Changjiang discharge induced different responses in the concentrations of nutrients,phytoplankton,and detritus in the ECS.Changes in dissolved inorganic nitrogen(DIN),silicate(SIL),phytoplankton,and detritus could be identified over a large area of the ECS shelf,but changes in dissolved inorganic phosphate(DIP)were limited to a small area close to the river mouth.The high DIN:DIP and SIL:DIP ratios in the river water were likely associated with the diff erent responses in DIN,DIP,and SIL.As DIP is a candidate limiting nutrient,perturbations in DIP resulting from changes in the Changjiang discharge are quickly consumed through primary production.It is interesting that an increase in the Changjiang discharge did not always lead to an increase in phytoplankton levels in the ECS.Phytoplankton decreases could be found in some areas close to the river mouth.A likely cause of the reduction in phytoplankton was a change in the hydrodynamic field associated with the river plume,although the present model is not suitable for examining the possibility in detail.Increases in DIN and DIP concentrations in the river water primarily led to increases in DIN,DIP,phytoplankton,and detritus levels in the ECS,whereas decreases in the SIL concentration in river water led to lower SIL concentrations in the ECS,indicating that SIL is not a limiting nutrient for photosynthesis,based on our model results from 1960 to 2005.In both of the above-mentioned cases,the sediment accumulation rate of detritus exhibited a large spatial variation near the river mouth,suggesting that core sample data should be carefully interpreted.展开更多
Coastal wetlands in the Yellow River Delta are typical new wetland ecosystems in warm temperate zone. In recent years, influenced by natural and human factors, these coastal wetlands in the Yellow River Delta have und...Coastal wetlands in the Yellow River Delta are typical new wetland ecosystems in warm temperate zone. In recent years, influenced by natural and human factors, these coastal wetlands in the Yellow River Delta have undergone changes of landscape fragmentation, vegetation degradation, pollution, species reduction, and harmful exotic species invasion. These changes have influenced sustainable and healthy development of marine economy of the Yellow River Delta. To protect natural ecological environment of the Yellow River Delta, the authors recommended that it should establish and improve policies, laws and regulations of wetland protection; carry out wetland resource investigation and assessment and monitoring; strengthen comprehensive protection and control of wetland; reduce wetland degradation and promote sustainable use of wetland.展开更多
Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods f...Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.展开更多
<span style="font-family:Verdana;">Riparian forests ecosystems play significant role in biodiversity conservation and provision of ecosystem goods and services which support local livelihoods. However,...<span style="font-family:Verdana;">Riparian forests ecosystems play significant role in biodiversity conservation and provision of ecosystem goods and services which support local livelihoods. However, riparian ecosystems are threatened by degradation attributed to anthropogenic activities. Understanding the interaction between anthropogenic activities and socio-economic factors, and their associated impact on riparian degradation is essential for designing appropriate management strategies for these ecosystems. This study assessed the socio-economic factors that drive degradation and their implication on conservation of River Lumi riparian ecosystem. Semi-structured questionnaires, Focus Group Discussion (FGDs) and key informant interviews were used to collect the data. The findings indicate that crop farming and livestock production were the main sources of livelihood practiced by 84% and 70% of the households respectively. Consequently, agricultural intensification resulting from increased demand for agricultural commodities (33%), over-grazing coupled with influx of livestock from private ranches and neighbouring pastoralist Maasai community (20%), and deforestation fuelled by population increase (17%) were the main drivers of degradation in River Lumi riparian ecosystem. The findings indicate that about 91% of the adjacent communities are dependent on River Lumi for their sustenance and their livelihoods will be affected by continued degradation of the riparian ecosystem;thus there is need for development of appropriate management strategies including sustainable livelihood systems to conserve River Lumi riparian ecosystem.</span>展开更多
Based on a database of more than 40 years of second production process and energy flow records for Maduo,Qumalai and Yushu counties,a dynamic model of the stress within grassland ecosys-tems was established using a no...Based on a database of more than 40 years of second production process and energy flow records for Maduo,Qumalai and Yushu counties,a dynamic model of the stress within grassland ecosys-tems was established using a nonlinear regression method for this source regions of the Yangtze and Yel-low Rivers.The results show that dynamic curves of stress within grassland ecosystems in the three coun-ties were in the shape of an inverted 'U' during the period 1965-2007.It also revealed that the variation in actual amount of livestock inventories reflected the general trends of the stress within the grassland eco-systems in the source regions,although there were many other factors for the increase or reduction in grassland ecosystem stress.展开更多
Riparian forests minimize impacts of land degradation on stream ecosystems and provide direct and indirect benefits to people. However, these ecosystems are threatened by degradation and deforestation attributed to la...Riparian forests minimize impacts of land degradation on stream ecosystems and provide direct and indirect benefits to people. However, these ecosystems are threatened by degradation and deforestation attributed to land use changes. River Lumi riparian ecosystem in Taita Taveta County in Kenya has experienced rapid and extensive land use changes over the past three decades in response to economic, institutional and demographic factors. There is growing concern of riparian degradation attributed to land use change with far reaching implications on local livelihoods. A study was conducted to examine the patterns </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">of land use and land cover change</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> along River Lumi riparian ecosystem between 1987 and 2019. The aim of the study was to ascertain the impacts of land use and land cover change on local livelihoods. Landsat images were used to assess land use and land cover change while socio-economic data was collected from 353 households in Njukini, Chala and Mboghoni located in the upper, middle and lower sections of River Lumi ecosystem respectively. Research evidence authenticated that the area under farmlands, settlement and water body increased by 20.5%, 112.1% and 2.3% respectively between 1987 and 2019 while area under forest patches, grazing land and riverine vegetation decreased by 52.7%, 3.0%, and 36.6% respectively. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The increase in population in surrounding areas coupled with encroachment of the riparian areas for crop farming and livestock grazing resulted to loss of riparian forest patches/vegetation and associated biodiversity with negative implications on household livelihoods. The implication of these results is the need for land use regulations and management interventions at the County level to arrest further encroachment of River Lumi riparian ecosystem and consequent loss of biodiversity and livelihoods.展开更多
Based on the investigation and analysis of protection and restoration of aquatic ecosystems in rivers and lakes of China, the ideas and measures of restoring aquatic ecosystems were proposed to build healthy aquatic e...Based on the investigation and analysis of protection and restoration of aquatic ecosystems in rivers and lakes of China, the ideas and measures of restoring aquatic ecosystems were proposed to build healthy aquatic ecosystems of rivers and lakes in China, such as setting scientific and clear goals, improving the standard adopted by wastewater treatment plants, controlling sources of pollutants and intercepting pollutants, collec- tion of blue-green algae, water transfer, dredging, reducing the quantity of blue-green algae, restoring reed wetlands on a large scale, combing dredging and base raise of restored reed wetlands, making full use of microorganisms, and implementing effective management, technology integra- tion and innovation.展开更多
This paper essayed to examine ecosystem functions with a case study of the tropical rainforest environment of the Cross River National Park, Nigeria. The paper highlighted the important functions of the ecosystems to ...This paper essayed to examine ecosystem functions with a case study of the tropical rainforest environment of the Cross River National Park, Nigeria. The paper highlighted the important functions of the ecosystems to include Purification of air and water mitigation of floods and droughts, detoxification and decomposition of wastes, generation and renewal of soil and natural vegetation, pollination of crops and natural vegetation, control of the vast majority of potential agricultural pests, dispersal of seeds and translocation of nutrients, maintenance of biodiversity, protection from the sun’s harmful ultraviolet rays among others. Problems associated with the rainforest ecosystems among which are logging, traditional methods of farming, poaching, excessive noise and encroachment were identified. The paper concluded by highlighting the way forward among others that, awareness creation should be stepped-up in Support Zone Communities;indigenes should be educated periodically on the benefits of the ecosystem services to not just humans but the forest resources and biodiversity themselves.展开更多
On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic be...On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.展开更多
River＇s healthy life is a description of their living conditions, and it is also a comprehensive assessment of river＇s functions and relations with the human society. Through analyzing the demands of human being and...River＇s healthy life is a description of their living conditions, and it is also a comprehensive assessment of river＇s functions and relations with the human society. Through analyzing the demands of human being and river ecosystem, the continuous flow, safe river channel for water and sediment transportation, good water quality, sustainable river ecosystem and water supply capacity are regarded as symbols of the healthy Yellow River. Minimum flow, maximum flood discharging capacity, bank-full discharge, transverse slope of floodplain, water quality degree, wetlands area, aquatic ecosystem, and water supply capacity, altogether eight quantitative indicators are set as symbols of healthy Yellow River, and their corresponding standards are determined based on the analysis with historical hydrological data and observed data of 1956-2004.展开更多
Rivers link terrestrial ecosystems and marine ecosystems, and they transport large amounts of substances into oceans each year, including several forms of silicon(Si), carbon(C), and other nutrients. However, river da...Rivers link terrestrial ecosystems and marine ecosystems, and they transport large amounts of substances into oceans each year, including several forms of silicon(Si), carbon(C), and other nutrients. However, river damming affects the water flow and biogeochemical cycles of Si, C, and other nutrients through biogeochemical interacting processes. In this review, we first summarize the current understanding of the effects of river damming on the processes of biogeochemical Si cycle, especially the source, composition, and recycling process of biogenic silica(BSi). Then, we introduce dam impacts on the cycles of C and some other nutrients. Dissolved silicon in rivers is mainly released from phytolith dissolution and silicate weathering. BSi in suspended matter or sediments in most rivers mainly consists of phytoliths and mainly originates from soil erosion. However, diatom growth and deposition in many reservoirs formed by river interception may significantly increase the contribution of diatom Si to total BSi, and thus significantly influence the biogeochemical Si,C, and nutrient cycles. Yet the turnover of phytoliths and diatoms in different rivers formed by river damming is still poorly quantified. Thus, they should be further investigated to enhance our understanding about the effects of river damming on global biogeochemical Si, C and nutrient cycles.展开更多
文摘Dam construction is an important engineering measure in dealing with the relationship between water and human being. However, with dam construction, some disadvantages to the river basin may be caused, including flow flux of downstream changed, flooded area reduced, river species and other organisms changed and substance sedimentation. Furthermore, it brings some diseases to human being and human residential areas reduced too. Based on the basic principles of ecohydralic engineering, some countermeasures to minimize the negative effects on rivers were put forward. They are reservoir ecological regulation, ecohydraulic engineering construction and comprehensive water pollution treatment.
基金Sponsored by Nanchong Science and Technology Project(18SXHZ0006)
文摘This paper analyzes the impact of human activities on river ecosystems from two aspects of agricultural production and watershed water conservancy project construction. Among them, dambased water conservancy projects have caused runoff patterns and artificial segmentation of rivers, which has seriously damaged the energy and material of river corridors as well as the capacity of species to transport the passage. Modern agricultural production not only uses a lot of pesticides and chemical fertilizers, but also occupies a large number of terraces and floodplains, directly leading to the emergence of non-point source pollution. Sometimes the runoff characteristics of the city will also be changed, so the ecological value of the rivers in the city is seriously damaged under such circumstances.
文摘Tropical river ecosystems are increasingly vulnerable to anthropogenic pressures,yet conventional monitoring methods remain inadequate to capture the rapid and complex ecological changes needed for effective conservation.This study presents“Smart River Watch,”a low-cost,IoT-based ecological monitoring system designed for real-time assessment of key water quality parameters—temperature,pH,and turbidity—in tropical river environments.The system combines Arduino Mega microcontrollers and high-precision sensors with ESP32 WiFi for continuous data transmission to cloud and mobile platforms.Field deployment across five ecologically distinct sites along Indonesia’s Martapura River demonstrated strong performance,achieving exceptional accuracy(r>0.99;error<2%)compared to laboratory methods,a 98.7%transmission success rate,and 23.4-hour operational autonomy.The innovation of this research lies in bridging technological accessibility with ecological needs:enabling high-frequency,real-time monitoring that supports early pollution detection,enhances ecological insight,and empowers local communities through user-friendly mobile interfaces.The cost-effectiveness,rapid deployment(15 minutes per site),and community-based usability of the system make it a scalable solution for biodiversity protection and adaptive water resource management in developing regions.These findings highlight a paradigm shift in ecological monitoring—merging digital innovation with ecosystem stewardship to better protect freshwater biodiversity in the face of accelerating environmental change.
基金supported by the Major Project Foundation of China National Social Science(14ZDB140)Fudan-UK Tyndall Foundat ion(FTC98503B03a,Urban Growth i1)+2 种基金the PhD Station Foundation Project of China National Education Minis-try(No.20060246024)the Scientific Innovation Project of Shanghai Municipal Education Commission(No.08ZZ03)the Youth Leadership Program(LINCS)of the State Department,USA,the Foundation of Foho Development Zone,Wujiang,Jiangshu,China,and the Think Tank Program of Fudan University(2015).
文摘Starting in the 1960s,a great deal of effort and capital was invested in an endeavor to significantlyimprove the quality of surface water around the United States,particularly in metropolises like New YorkCity,New York.The Hudson River has been at the forefront of these efforts and has benefited immenselyfrom this campaign.In parts of the developing world,such as China,similar efforts are beginning to gatherthe same type of momentum.Within the past decade,the Huangpu River,which flows through Shanghaiinto the Yangtze Estuary of China,has been a target for ecological restoration and management.It is possibleto draw parallels between the cleanup efforts involved in improving the environmental conditions of theHuangpu and Hudson Rivers.Using the methodologies of series comparison(SCM),water quality index(WQI)modeling,consideration of ecological engineering,and policy strategy design,we comparativelystudied the topography,functions,environmental conditions,ecological engineering countermeasures,andmanagement policies of the two rivers to assist future forecasting of ecological restoration efforts in China.
基金supported by the NationalNatural Science Foundation of China (No.52293442)the Special Fund from the State Key Joint Laboratory of Environment Simulation and Pollution Control (No.22Z01ESPCR)。
文摘Traditional river health assessment relies on limited water quality indices and representative organism activity,but does not comprehensively obtain biotic and abiotic information of the ecosystem.Here,we propose a new approach to evaluate the ecological and health risks of river aquatic ecosystems.First,detailed physicochemical and biological characterization of a river ecosystem can be obtained through pollutant determination(especially emerging pollutants)and DNA/RNA sequencing.Second,supervised machine learning can be applied to perform classification analysis of characterization data and ascertain river ecosystem ecology and health.Our proposed methodology transforms river ecosystem health assessment and can be applied in river management.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFC3201803National Natural Science Foundation of China,Grant/Award Numbers:12272209,U2040214。
文摘River ecosystems face challenges due to environmental degradation and alterations in flow and sediment transport resulting from climate change and other anthropogenic impacts.These changes may substantially affect river morphology,nutrient dynamics,wetland vegetation,aquatic habitats,and river ecological stability.This highlights the urgent need for systematic and quantitative studies on the interactions and feedback between changes in flow,sediment transport,and river ecology.In this study,we reviewed flow and sediment transport changes in major Chinese rivers,along with their resulting ecological impacts.We propose conducting eco-fluvial dynamic studies,a potential solution that can guide the evaluation and restoration of ecological health impacted by physical processes.These studies can provide major benefits in balancing human and environmental needs in large river systems,which is crucial for the healthy and sustainable development of rivers.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences(KSCX-07-02)
文摘By using the concept of emergy and method of emergy analysis, this paper has studied two mountain settlement (village) ecosystems in two aspects: input and output of energy in the agro-systems and the use of fuel energy. The result reveals that the settlement agro-system in the valley of Minjiang River is better in both structure and function than that at the so-called half-high mountain. The former one is higher than the latter one regarding such indices as emergy yield ratio, labor productivity of emergy and emergy sustainable index, but lower than the latter one regarding environmental loading ratio. In terms of fuel emergy, the settlement in the valley enjoys more diversified sources and is less depending on bio-energy while the settlement at the half-high mountain has only one source (i. e. fuel wood) , much depending on bio-energy, may exert a greater pressure on environment.
基金the support of the UNESCO HELP programthe support of K.C.Wong Education Foundation,Hong Kong
文摘Rapid population growth and artificial oasis enlargement did pose great threat to the natural riparian ecosystems of Tarim River and caused seriously ecological deterioration and greater desertification of the Tarim River Basin in the second half of 20 century. Restoration of the endangered riparian ecosystem requires that environmental flow should be restored through restricted and uncontrolled flow diversion irrigation in tributary areas. Implementation of such restriction needs further the basin-wide reallocation of water resources through a set of engineering and non-engineering measures taken to ensure the water requirement in the tributary and maintain effective flows in Tarim River. As one of evolving HELP (Hydrology for Environment, Life and Policy) basins, the article first presents an overview of hydrology, socio-economic development and ecosystem evolution of the Tarim River Basin. Then, those measures for restoring and maintaining environmental flow are reviewed and analyzed along with its applicability and validity. The issues emerging in implementing those measures are also explored, and then the conclusions were summarized. Lessons learned could provide a good example for other basins under similar conditions.
基金Supported by the National Basic Research Program of China(973 Program)(No.2012CB956004)the National Natural Science Foundation of China(NSFC)(No.41576010)+5 种基金the JSPS KAKENHI(Nos.JP26241009,JP26287116,JPH05821)the Fundamental Research Funds for Central Universities from the Ministry of Education of China(No.201512004)to X.Guothe Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020305)the NSFC(No.41276016)the National Key Research and Development Program of China(No.2016YFA0601301)the Ministry of Education,Culture,Sports,Science and Technology,Japan(MEXT),under a Joint Usage/Research Center,Leading Academia in Marine and Environment Pollution Research(LaMer)Project to L.Zhao
文摘Using a three-dimensional coupled biophysical model,we simulated the responses of a lowtrophic ecosystem in the East China Sea(ECS)to long-term changes in nutrient load from the Changjiang(Yangtze)River over the period of 1960–2005.Two major factors aff ected changes in nutrient load:changes in river discharge and the concentration of nutrients in the river water.Increasing or decreasing Changjiang discharge induced different responses in the concentrations of nutrients,phytoplankton,and detritus in the ECS.Changes in dissolved inorganic nitrogen(DIN),silicate(SIL),phytoplankton,and detritus could be identified over a large area of the ECS shelf,but changes in dissolved inorganic phosphate(DIP)were limited to a small area close to the river mouth.The high DIN:DIP and SIL:DIP ratios in the river water were likely associated with the diff erent responses in DIN,DIP,and SIL.As DIP is a candidate limiting nutrient,perturbations in DIP resulting from changes in the Changjiang discharge are quickly consumed through primary production.It is interesting that an increase in the Changjiang discharge did not always lead to an increase in phytoplankton levels in the ECS.Phytoplankton decreases could be found in some areas close to the river mouth.A likely cause of the reduction in phytoplankton was a change in the hydrodynamic field associated with the river plume,although the present model is not suitable for examining the possibility in detail.Increases in DIN and DIP concentrations in the river water primarily led to increases in DIN,DIP,phytoplankton,and detritus levels in the ECS,whereas decreases in the SIL concentration in river water led to lower SIL concentrations in the ECS,indicating that SIL is not a limiting nutrient for photosynthesis,based on our model results from 1960 to 2005.In both of the above-mentioned cases,the sediment accumulation rate of detritus exhibited a large spatial variation near the river mouth,suggesting that core sample data should be carefully interpreted.
基金Supported by the Open Research Fund Program of the Key Laboratory of Marine Ecology and Environmental Science and Engineering,SOA (MESE-2012-04)the Special Funds Projects for Public Welfare of National Ocean Industries (201105005)
文摘Coastal wetlands in the Yellow River Delta are typical new wetland ecosystems in warm temperate zone. In recent years, influenced by natural and human factors, these coastal wetlands in the Yellow River Delta have undergone changes of landscape fragmentation, vegetation degradation, pollution, species reduction, and harmful exotic species invasion. These changes have influenced sustainable and healthy development of marine economy of the Yellow River Delta. To protect natural ecological environment of the Yellow River Delta, the authors recommended that it should establish and improve policies, laws and regulations of wetland protection; carry out wetland resource investigation and assessment and monitoring; strengthen comprehensive protection and control of wetland; reduce wetland degradation and promote sustainable use of wetland.
基金Project supported by the China Scholarship Council and the National Basic Research Program (973) of China (No. 2002CCA00300).
文摘Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.
文摘<span style="font-family:Verdana;">Riparian forests ecosystems play significant role in biodiversity conservation and provision of ecosystem goods and services which support local livelihoods. However, riparian ecosystems are threatened by degradation attributed to anthropogenic activities. Understanding the interaction between anthropogenic activities and socio-economic factors, and their associated impact on riparian degradation is essential for designing appropriate management strategies for these ecosystems. This study assessed the socio-economic factors that drive degradation and their implication on conservation of River Lumi riparian ecosystem. Semi-structured questionnaires, Focus Group Discussion (FGDs) and key informant interviews were used to collect the data. The findings indicate that crop farming and livestock production were the main sources of livelihood practiced by 84% and 70% of the households respectively. Consequently, agricultural intensification resulting from increased demand for agricultural commodities (33%), over-grazing coupled with influx of livestock from private ranches and neighbouring pastoralist Maasai community (20%), and deforestation fuelled by population increase (17%) were the main drivers of degradation in River Lumi riparian ecosystem. The findings indicate that about 91% of the adjacent communities are dependent on River Lumi for their sustenance and their livelihoods will be affected by continued degradation of the riparian ecosystem;thus there is need for development of appropriate management strategies including sustainable livelihood systems to conserve River Lumi riparian ecosystem.</span>
基金supported by a grant from the National Basic Research Program of China (2007CB411507)Open Fund of the State Key Laboratory of Cryosphere Science (SKLCS08-05)
文摘Based on a database of more than 40 years of second production process and energy flow records for Maduo,Qumalai and Yushu counties,a dynamic model of the stress within grassland ecosys-tems was established using a nonlinear regression method for this source regions of the Yangtze and Yel-low Rivers.The results show that dynamic curves of stress within grassland ecosystems in the three coun-ties were in the shape of an inverted 'U' during the period 1965-2007.It also revealed that the variation in actual amount of livestock inventories reflected the general trends of the stress within the grassland eco-systems in the source regions,although there were many other factors for the increase or reduction in grassland ecosystem stress.
文摘Riparian forests minimize impacts of land degradation on stream ecosystems and provide direct and indirect benefits to people. However, these ecosystems are threatened by degradation and deforestation attributed to land use changes. River Lumi riparian ecosystem in Taita Taveta County in Kenya has experienced rapid and extensive land use changes over the past three decades in response to economic, institutional and demographic factors. There is growing concern of riparian degradation attributed to land use change with far reaching implications on local livelihoods. A study was conducted to examine the patterns </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">of land use and land cover change</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> along River Lumi riparian ecosystem between 1987 and 2019. The aim of the study was to ascertain the impacts of land use and land cover change on local livelihoods. Landsat images were used to assess land use and land cover change while socio-economic data was collected from 353 households in Njukini, Chala and Mboghoni located in the upper, middle and lower sections of River Lumi ecosystem respectively. Research evidence authenticated that the area under farmlands, settlement and water body increased by 20.5%, 112.1% and 2.3% respectively between 1987 and 2019 while area under forest patches, grazing land and riverine vegetation decreased by 52.7%, 3.0%, and 36.6% respectively. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The increase in population in surrounding areas coupled with encroachment of the riparian areas for crop farming and livestock grazing resulted to loss of riparian forest patches/vegetation and associated biodiversity with negative implications on household livelihoods. The implication of these results is the need for land use regulations and management interventions at the County level to arrest further encroachment of River Lumi riparian ecosystem and consequent loss of biodiversity and livelihoods.
文摘Based on the investigation and analysis of protection and restoration of aquatic ecosystems in rivers and lakes of China, the ideas and measures of restoring aquatic ecosystems were proposed to build healthy aquatic ecosystems of rivers and lakes in China, such as setting scientific and clear goals, improving the standard adopted by wastewater treatment plants, controlling sources of pollutants and intercepting pollutants, collec- tion of blue-green algae, water transfer, dredging, reducing the quantity of blue-green algae, restoring reed wetlands on a large scale, combing dredging and base raise of restored reed wetlands, making full use of microorganisms, and implementing effective management, technology integra- tion and innovation.
文摘This paper essayed to examine ecosystem functions with a case study of the tropical rainforest environment of the Cross River National Park, Nigeria. The paper highlighted the important functions of the ecosystems to include Purification of air and water mitigation of floods and droughts, detoxification and decomposition of wastes, generation and renewal of soil and natural vegetation, pollination of crops and natural vegetation, control of the vast majority of potential agricultural pests, dispersal of seeds and translocation of nutrients, maintenance of biodiversity, protection from the sun’s harmful ultraviolet rays among others. Problems associated with the rainforest ecosystems among which are logging, traditional methods of farming, poaching, excessive noise and encroachment were identified. The paper concluded by highlighting the way forward among others that, awareness creation should be stepped-up in Support Zone Communities;indigenes should be educated periodically on the benefits of the ecosystem services to not just humans but the forest resources and biodiversity themselves.
文摘On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.
基金The Technological Innovative Plan of Ministry of Water Resources, China, No.XDS2004-03
文摘River＇s healthy life is a description of their living conditions, and it is also a comprehensive assessment of river＇s functions and relations with the human society. Through analyzing the demands of human being and river ecosystem, the continuous flow, safe river channel for water and sediment transportation, good water quality, sustainable river ecosystem and water supply capacity are regarded as symbols of the healthy Yellow River. Minimum flow, maximum flood discharging capacity, bank-full discharge, transverse slope of floodplain, water quality degree, wetlands area, aquatic ecosystem, and water supply capacity, altogether eight quantitative indicators are set as symbols of healthy Yellow River, and their corresponding standards are determined based on the analysis with historical hydrological data and observed data of 1956-2004.
基金the support from the State's Key Project of Research and Development Plan of China (2016YFA0601002)the National Natural Science Foundation of China (41522207,41571130042)
文摘Rivers link terrestrial ecosystems and marine ecosystems, and they transport large amounts of substances into oceans each year, including several forms of silicon(Si), carbon(C), and other nutrients. However, river damming affects the water flow and biogeochemical cycles of Si, C, and other nutrients through biogeochemical interacting processes. In this review, we first summarize the current understanding of the effects of river damming on the processes of biogeochemical Si cycle, especially the source, composition, and recycling process of biogenic silica(BSi). Then, we introduce dam impacts on the cycles of C and some other nutrients. Dissolved silicon in rivers is mainly released from phytolith dissolution and silicate weathering. BSi in suspended matter or sediments in most rivers mainly consists of phytoliths and mainly originates from soil erosion. However, diatom growth and deposition in many reservoirs formed by river interception may significantly increase the contribution of diatom Si to total BSi, and thus significantly influence the biogeochemical Si,C, and nutrient cycles. Yet the turnover of phytoliths and diatoms in different rivers formed by river damming is still poorly quantified. Thus, they should be further investigated to enhance our understanding about the effects of river damming on global biogeochemical Si, C and nutrient cycles.
