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Phytoplankton functional groups in Poyang Lake:succession and driving factors 被引量:2
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作者 Jinfu LIU Haoyue ZOU +10 位作者 Feng DENG Yutian LIU Wei LI Jinying XU Songping LIU Qiang WU Xiaoliang ZHANG Fagen WENG Qi HUANG Hailin YOU Yuwei CHEN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第6期1764-1776,共13页
Phytoplankton functional groups have gained increasing attention in recent years.To understand the composition of phytoplankton functional groups in Poyang Lake and their drivers,field investigations were conducted ov... Phytoplankton functional groups have gained increasing attention in recent years.To understand the composition of phytoplankton functional groups in Poyang Lake and their drivers,field investigations were conducted over three years:2013,2014,and 2016.Phytoplankton were dominated by diatoms,contributing from 20.19%to 57.57%of the total biomass,followed by cyanobacteria,9.81%-39.98%.Microcystis sp.and Anabaena sp.were the dominant species among cyanobacteria.Twenty-six functional groups were identified among 72 genera or species,and fiver groups(P,B,MP,H1,and G)were categorized dominant.All of dominant groups except H1 were tolerate highly fluctuating mixing intensities and showed a typical monthly succession variation.Water temperature,water level,and nutrients are key drivers for the variation of phytoplankton communities at taxonomic and functional levels.Both of redundancy and variation partitioning analyses showed that environmental variables might explain functional groups better than taxonomic communities,implying that the functional groups were more advantageous in showing the effects of environmental conditions than taxonomic compositions.Hydrological conditions have a crucial influence on phytoplankton assemblage dynamics in highly variable water regime lakes,but not in the largest ones.The functional groups method is suitable for identifying the spatial and seasonal characteristics of aquatic environments that significantly affected by water regimes. 展开更多
关键词 cyanobacteria bloom light availability nutrients dilution water level poyang Lake
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Spatiotemporal Differentiation of Urban Spatial Form and Carbon Emissions in Poyang Lake City Group
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作者 LUO Xiaolin LI Zhi CHU Xi 《Journal of Landscape Research》 2024年第2期87-92,共6页
In response to the inherent requirements of low-carbon land spatial planning in Jiangxi Province and the lack of existing research,this paper explored the mechanism of spatial form elements of Poyang Lake urban agglom... In response to the inherent requirements of low-carbon land spatial planning in Jiangxi Province and the lack of existing research,this paper explored the mechanism of spatial form elements of Poyang Lake urban agglomeration on urban carbon emissions.Based on generalized linear regression and geographically weighted regression models,this paper analyzed the spatiotemporal distribution characteristics of carbon emissions,the spatiotemporal relationship between urban form index and carbon emissions,and the spatial differentiation of the intensity of dominant factors from 63 county-level administrative units in the Poyang Lake city group from 2005 to 2020.The results showed that:①The carbon emissions of urban agglomerations around Poyang Lake are generally increasing,and the spatial distribution of carbon emissions is characterized by high-value concentration in the middle and low-value agglomeration in pieces;②The main driving factor for the spatial heterogeneity of carbon emissions was the expansion of built-up area;③Improving urban compactness and optimizing urban form could effectively reduce urban carbon emissions.The results showcased the correlation between urban spatial landscape pattern and the spatiotemporal distribution of carbon emissions,which could make the low-carbon land spatial planning in the Poyang Lake city group more reasonable and practical. 展开更多
关键词 Carbon emissions Urban spatial form the poyang Lake city group Landscape pattern index Geographically weighted regression
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Vertical Distribution Characteristic of Nitrogen in the Core Sediments of Three Rivers Estuary in Poyang Lake 被引量:4
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作者 王毛兰 艾永平 周文斌 《Agricultural Science & Technology》 CAS 2010年第2期155-158,共4页
The vertical profile distribution characteristics of nitrogen in core sediments of Three Rivers Estuary in Poyang Lake were studied.The results showed that TN content in core sediments ranged from 480.0 to 1 900.0 μg... The vertical profile distribution characteristics of nitrogen in core sediments of Three Rivers Estuary in Poyang Lake were studied.The results showed that TN content in core sediments ranged from 480.0 to 1 900.0 μg/g with the change of depth,which was divided into three distribution types as follows:TN content decreases gradually with the increase of depth,TN content increases gradually with the increase of depth or higher content in the middle but lower content in two ends.NH4+-N content ranged from 8.7 ... 展开更多
关键词 Three Rivers Estuary of poyang Lake Core sediment NITROGEN Distribution characteristic
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Spatiotemporal Comparative Analysis of Ecological Footprint of Poyang Lake Area and Five River Watersheds in Jiangxi Province 被引量:1
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作者 贾俊松 谢冬明 +1 位作者 郑博福 邓红兵 《Journal of Landscape Research》 2009年第2期25-30,共6页
The Jiangxi province was divided into seven parts according to the concept of watershed,namely Poyang lake area,Fuhe,Xinjiang,Ganjiang,Xiuhe,Raohe and other river watersheds.The ecological supply and demands status of... The Jiangxi province was divided into seven parts according to the concept of watershed,namely Poyang lake area,Fuhe,Xinjiang,Ganjiang,Xiuhe,Raohe and other river watersheds.The ecological supply and demands status of the former six parts from 2000 to 2006 was computed based on the ecological footprint model and a spatiotemporal comparative analysis to them was conducted.The result showed that:①all the studied areas had an increasing ecological deficit and they were in the status of unsustainable development;② the arable land footprint's demand were about 80% of their total footprint's demand respectively,so it was of great significance to protect and exploit arable land resources scientifically;③ the ecological deficit of grassland and forest resources can not be ignored. 展开更多
关键词 Ecological footprint DEFICIT poyang lake Watersheds SPATIOTEMPORAL
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Study on Safeguard System of Eco-tourism Compensation of Hukou Section during Ecological Water-control Project of Poyang Lake 被引量:1
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作者 龚双双 沈中印 +1 位作者 孙冬英 杨云仙 《Journal of Landscape Research》 2010年第12期58-62,72,共6页
Through analysis on the background to develop eco-tourism and necessity for ecological compensation,based on specific condition of Hukou County,in line with the situation to develop eco-tourism during ecological water... Through analysis on the background to develop eco-tourism and necessity for ecological compensation,based on specific condition of Hukou County,in line with the situation to develop eco-tourism during ecological water control project of Poyang Lake,residents' interest protection system and ecological benefit safeguard system for eco-tourism compensation were put forward. 展开更多
关键词 poyang Lake ECOLOGICAL WATER control project ECO-TOURISM COMPENSATION Hukou SECTION
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Study on Regionalization of High Efficiency Eco-agriculture in Eco-economic Zone of Poyang Lake 被引量:11
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作者 戴天放 章志发 《Agricultural Science & Technology》 CAS 2010年第8期57-60,共4页
The high efficient eco-agricultural zone in Eco-economic Region of Poyang Lake was divided into three different areas. 12 indicators including per capita cultivated land,forest coverage,comprehensive utilization rate ... The high efficient eco-agricultural zone in Eco-economic Region of Poyang Lake was divided into three different areas. 12 indicators including per capita cultivated land,forest coverage,comprehensive utilization rate of straw,the ratio of the effective irrigation area to the arable land,amount of pesticide usage per unit area of arable land,the output value ratio of planting industry,the output value ratio of forestry and fruit industry,the output value ratio of stock farming,the output value ratio of fishery,the proportion of sown area of crop,proportion of sown area of oil plants and the proportion of sown area of vegetable were screened to construct the indicator system of regionalization of high efficient eco-agriculture. The average index values of the high efficient eco-agricultural regionalization of three regions were obtained,the development direction of the efficient eco-agriculture construction of three areas were analyzed according to the natural resources characteristics f eco-agricultural and requirements of high efficient eco-agricultural development of the regions. 展开更多
关键词 poyang Lake Eco-economic Region Efficient eco-agriculture REGIONALIZATION
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Foundation for the Formation and Development of Lushan-Poyang Lake Eco-civilization 被引量:1
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作者 冯长明 王咏红 李松志 《Journal of Landscape Research》 2010年第2期60-63,共4页
Lushan-Poyang Lake Eco-civilization is the joint product of natural process and regional characteristics in the evolution of history, the formation factors and status of Lushan-Poyang Lake eco-civilization were clarif... Lushan-Poyang Lake Eco-civilization is the joint product of natural process and regional characteristics in the evolution of history, the formation factors and status of Lushan-Poyang Lake eco-civilization were clarified by understanding its natural geographical foundation, regional culture foundation, environmental philosophy foundation and production practice foundation, to provide theoretical support for the future construction of Lushan-Poyang Lake eco-civilization. 展开更多
关键词 Lushan poyang Lake Eco-civilization FOUNDATION
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Research on the Development of Leisure Agriculture Tourism in the Area around Poyang Lake
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作者 冯安峰 王燕华 《Journal of Landscape Research》 2010年第5期60-63,共4页
Leisure agriculture tourism is the combination of agriculture and tourism,which is an important part of the new rural construction.The area around Poyang Lake is rich in flora and fauna,landscape,agricultural and fish... Leisure agriculture tourism is the combination of agriculture and tourism,which is an important part of the new rural construction.The area around Poyang Lake is rich in flora and fauna,landscape,agricultural and fishing products,folk and other natural and cultural resources,so it has good infrastructure of leisure agriculture tourism.Under the background of the formal approval of "Planning of eco-economical region in the area of Poyang Lake in Jiangxi Province" by the State Council,which aims to escalate the constructing of Poyang Lake from eco-economical region to national strategic policy,leisure agriculture tourism in the area around Poyang Lake has broad development prospects.This paper discussed the advantages,and disadvantages of the development and management of leisure agriculture tourism in the area around Poyang Lake,and also put forward some suggestions and countermeasures. 展开更多
关键词 The area AROUND poyang LAKE LEISURE AGRICULTURE Suggestions and COUNTERMEASURES
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Research of Informatization Demands of New Countryside in Poyang Lake Ecological Economic Zone and Related Countermeasures
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作者 戴天放 陈智辉 《Agricultural Science & Technology》 CAS 2012年第12期2675-2680,共6页
[Objective] The aim was to survey and analyze informatization demand in new countryside in Poyang Lake Ecological Economic Zone and to propose counter- measures, [Method] A questionnaire was made among farmers on info... [Objective] The aim was to survey and analyze informatization demand in new countryside in Poyang Lake Ecological Economic Zone and to propose counter- measures, [Method] A questionnaire was made among farmers on informatization de- mands in different regions in Poyang Lake Ecological Economic Zone and the re- sults were analyzed to propose countermeasures promoting informatization. [Result] With strengthening of information awareness, information demands in rural areas in Poyang Lake Ecological Economic Zone change as follows: Information demand car- rier changes from traditional media to modern media; demand on information content changes from one-way to diversified one; demand of information service changes from one-way transmission to interaction and exchange. However, some problems still exist in informatization process, such as poor infrastructure, dispersed information resources, higher information expense and shortage of information-based talents. Hence, the countermeasures were proposed, as follows: Rational security systems should be established; financing should be as diversified as possible; informatization infrastructure should be reinforced; agricultural economic information and informatiza- tion service system should be established. [Conclusion] The research lays foundation for construction of informatization in new countryside in Poyang Lake Ecological Economic Zone. 展开更多
关键词 poyang Lake Ecological Economic Zone Informatization demand by farmers SURVEY COUNTERMEASURES
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Tourism Development Strategy in Poyang Lake Eco-economic Area from the Perspective of Industrial Cluster
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作者 严宽荣 《Journal of Landscape Research》 2010年第3期67-70,共4页
As a regional tourism development strategy, tourism industrial cluster can promote the core competitiveness of tourism industry in advantageous regions and the great-leap-forward development of regions with less-devel... As a regional tourism development strategy, tourism industrial cluster can promote the core competitiveness of tourism industry in advantageous regions and the great-leap-forward development of regions with less-developed tourism industry. The conditions of forming tourism industrial cluster in Poyang Lake Eco-economic Area was analyzed, the development strategies for tourism industry from the perspective of industrial cluster was put forward. 展开更多
关键词 Industrial cluster poyang Lake Eco-economic Area Tourism industry
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Study on Planning and Design Mode of Eco-agricultural Demonstration Base in Poyang Lake Eco-economic Zone 被引量:2
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作者 魏朝俊 徐芳 《Journal of Landscape Research》 2012年第6期24-26,共3页
Guided by the Planning of Poyang Lake Eco-economic Zone, traffic and geographic conditions of the Eco-agricultural Demonstration Base in the study area were analyzed, and design principles proposed as "adaptation... Guided by the Planning of Poyang Lake Eco-economic Zone, traffic and geographic conditions of the Eco-agricultural Demonstration Base in the study area were analyzed, and design principles proposed as "adaptation to local conditions, scientific planning, benign circulation and sustainable development". Detailed planning and design was interpreted from the perspectives of infrastructure planning and functional area planning. Specifically, infrastructure construction should focus on traffic design, water, power and gas supply design, and also architectural design; while functional areas should be gradually developed from south section to central and then north section. It was to establish a design and planning mode that can be widely applied. 展开更多
关键词 PLANNING of poyang Lake Eco-economic Zone PLANNING and design of eco-agricultural BASE PLANNING of functional area Widely-applicable MODE
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Changes in rice cropping systems in the Poyang Lake Region, China during 2004-2010 被引量:25
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作者 LI Peng FENG Zhiming +2 位作者 JIANG Luguang LIU Yujie XIAO Xiangming 《Journal of Geographical Sciences》 SCIE CSCD 2012年第4期653-668,共16页
Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems. Yet, it is always affected by... Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems. Yet, it is always affected by external factors, like agricultural policies. Since 2004, seven consecutive No.1 Central Documents issued by the Central Government have focused on agricultural development in China. So far, few studies have investigated the effects of these policies on the rice cropping systems. In this study, based upon the long-term field survey information on paddy rice fields, we proposed a method to discriminate the rice cropping systems with Landsat data and quantified the spatial variations of rice cropping systems in the Poyang Lake Region (PLR), China. The results revealed that: (1) from 2004 to 2010, the decrement of paddy rice field was 46.76 km2 due to the land use change. (2) The temporal dynamics of NDVI derived from Landsat historical images could well characterize the temporal development of paddy rice fields. NDVI curves of single cropping rice fields showed one peak, while NDVI curves of double cropping rice fields displayed two peaks annually. NDVI of fallow field fluctuated between 0.15 and 0.40. NDVI of the flooded field during the transplanting period was relatively low, about 0.20±0.05, while NDVI during the period of panicle initiation to heading reached the highest level (above 0.80). Then, several temporal windows were determined based upon the NDVI variations of different rice cropping systems. (3) With the spatial pattern of paddy rice field and the NDVI threshold within optimum temporal windows, the spatial variation of rice cropping systems was very obvious, with an increased multiple cropping index of rice about 20.2% from 2004 to 2010. The result indicates that agricultural policies have greatly enhanced the food provision services in the PLR, China. 展开更多
关键词 rice cropping systems NDVI temporal windows threshold method LANDSAT the poyang Lake region(PLR)
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Study on Artificial Propagation and Embryonic Development of Poyang Lake Catfish 被引量:1
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作者 姚毅 付婷 +2 位作者 胡峻峰 蓝岚 侯玉洁 《Agricultural Science & Technology》 CAS 2016年第10期2334-2337,2413,共5页
Poyang Lake catfish (Silurus asotus Linnaeus) is native to Poyang Lake Basin. Artificial propagation of Poyang Lake catfish was carried out by using artificial insemination. Under water temperature of 18-26 ℃, embr... Poyang Lake catfish (Silurus asotus Linnaeus) is native to Poyang Lake Basin. Artificial propagation of Poyang Lake catfish was carried out by using artificial insemination. Under water temperature of 18-26 ℃, embryonic development of Poyang Lake catfish in impounded water was observed and recorded in detail. Embryonic development of Poyang Lake catfish encountered seven stages, and it last- ed for 47.08 h from the fertilized egg stage to the stripping stage. The hatching time of Silurus meridionalis Chen was shortest, followed by that of Poyang Lake catfish, and the hatching time of Pelteobagrus vachelli was longest. 展开更多
关键词 poyang Lake catfish Artificial insemination Embryonic development observation
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Non-stationary water-level fluctuation in China's Poyang Lake and its interactions with Yangtze River 被引量:19
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作者 DAI Xue WAN Rongrong YANG Guishan 《Journal of Geographical Sciences》 SCIE CSCD 2015年第3期274-288,共15页
Seasonal water-level fluctuations (WLF) play a dominate role in lacustrine ecosys- tems. River-lake interaction is a direct factor in changes of seasonal lake WLF, especially for those lakes naturally connected to u... Seasonal water-level fluctuations (WLF) play a dominate role in lacustrine ecosys- tems. River-lake interaction is a direct factor in changes of seasonal lake WLF, especially for those lakes naturally connected to upstream and downstream rivers. During the past decade, the modification of WLF in the Poyang Lake (the largest freshwater lake in China) has caused intensified flood and irrigation crises, reduced water availability, compromised water quality and extensive degradation of the lake ecosystem. There has been a conjecture as to whether the modification was caused by its interactions with Yangtze River. In this study, we investi- gated the variations of seasonal WLF in China's Poyang Lake by comparing the water levels during the four distinct seasons (the dry season, the rising season, the flood season, and the retreating season) before and after 2003 when the Three Gorge Dam operated. The Water Surface Slope (WSS) was used as a representative parameter to measure the changes in river-lake interaction and its impacts on seasonal WLF. The results showed that the magni- tude of seasonal WLF has changed considerably since 2003; the seasonal WLF of the Poy- ang Lake have been significantly altered by the fact that the water levels both rise and retreat earlier in the season and lowered water levels in general. The fluctuations of river-lake in- teractions, in particular the changes during the retreating season, are mainly responsible for these variations in magnitude of seasonal WLF. This study demonstrates that WSS is a rep- resentative parameter to denote river-lake interactions, and the results indicate that more emphasis should be placed on the decrease of the Poyang Lake caused by the lowered water levels of the Yangtze River, especially in the retreating season. 展开更多
关键词 seasonal water-level fluctuations in lakes slope of water surface river-lake interactions poyang Lake
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Effects of Water-table Depth and Soil Moisture on Plant Biomass, Diversity, and Distribution at a Seasonally Flooded Wetland of Poyang Lake, China 被引量:29
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作者 XU Xiuli ZHANG Qi +2 位作者 TAN Zhiqiang LI Yunliang WANG Xiaolong 《Chinese Geographical Science》 SCIE CSCD 2015年第6期739-756,共18页
Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dra... Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dramatic changes in hydrological conditions in last decade, which greatly influenced the wetland vegetations. To explore the relationships between hydrology and vegetation distri- bution, water-table depth, soil moisture, species composition, diversity and biomass were measured at a seasonally flooded wetland section at Wucheng National Nature Reserve. Three plant communities, Artemisia capillaris, Phragmites australis and Carex cineras- cens communities, were examined which are zonally distributed from upland to lakeshore with decreasing elevation. Canonical corre- spondence analysis (CCA), spearmen correlation and logistic regression were adopted to analyze the relationships between vegetation characteristics and hydrological variables of water-table depth and soil moisture. Results show that significant hydrological gradient exist along the wetland transect. Water-table demonstrates a seasonal variation and is consistently deepest in A. capillaris community (ranging from q).5 m above ground to +10.3 m below ground), intermediate in P. australis community (-2.6 m to +7.8 m) and shallow- est in C. cinerascens community (-4.5 m to +6.1 m). Soil moisture is lowest and most variable in A. capillaris community, highest and least variable in P. australis community, and intermediate and moderate variable in C. cinerascens community. The CCA ordination indicated that variables of water-table depth and soil moisture are strongly related to community distribution, which explained 81.7% of the vegetation variations. Species diversity indices are significantly positively correlated with soil moisture and negatively correlated with moisture variability, while above- and belowground biomass are positively correlated with moisture. Above- and belowground biomass present Gaussian models along the gradient of average water-table depth in growing season, while species diversity indices show bimodal patterns. The optimal average water-table depths for above- and belowground biomass are 0.8 m and 0.5 m, respectively, and are 2.2 m and 2.4 m for species richness and Shannon-Wiener indices, respectively. Outcomes of this work improved the under- standings of the relationship between hydrology and vegetation. 展开更多
关键词 water-table depth soil moisture species diversity BIOMASS Gaussian model poyang Lake wetland
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Study of heavy metal speciation in branch sediments of Poyang Lake 被引量:11
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作者 LUO Mingbiao LI Jianqiang +1 位作者 CAO Weipeng WANG Maolan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第2期161-166,共6页
This study concentrates on the environmental pollution level of sediments in the six branches of Poyang Lake, the biggest fresh water lake in China. This is the first systematic report on the speciation analysis of he... This study concentrates on the environmental pollution level of sediments in the six branches of Poyang Lake, the biggest fresh water lake in China. This is the first systematic report on the speciation analysis of heavy metals (Cu, Co, Cd, Pb, and Ni) in the six branches of the lake. A reported analytical procedure involving a five-step sequential extraction is used for the partition of particulating heavy metals. The sediment samples are analyzed using flame atomic absorption spectroscopy (FAAS). Experimental results obtained from five replicate samples of fluvial bottom surface sediments at the sampling points demonstrated that the relative standard deviation of the sequential extraction procedure was generally better than 10% (Cd except). The average extracted contents of the five elements, analyzed after all five steps, are found to be (mg/kg) for Cu: 26.89, Co: 16.25, Cd: 1.08, Pb: 37.98, and Ni: 20.46. The content of the exchangeable species was generally lower. Except Cu, the percentage of the species bond to organic matter was lower than 20%. The fractions containing the most metal for Cu, Co, and Ni were the residues (52.26%, 45.28%, and 74.82%, respectively). 展开更多
关键词 poyang Lake speciation analysis heavy metal sequential extraction
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Dissolved nitrous oxide and emission relating to denitrification across the Poyang Lake aquatic continuum 被引量:6
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作者 Huaxin Wang Lu Zhang +2 位作者 Xiaolong Yao Bin Xue Weijin Yan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第2期130-140,共11页
Most aquatic ecosystems contribute elevated N2 O to atmosphere due to increasing anthropogenic nitrogen loading. To further understand the spatial heterogeneity along an aquatic continuum from the upriver to wetland t... Most aquatic ecosystems contribute elevated N2 O to atmosphere due to increasing anthropogenic nitrogen loading. To further understand the spatial heterogeneity along an aquatic continuum from the upriver to wetland to lake to downriver, the study was conducted on spatial variations in N2 O emission along Poyang Lake aquatic continuum during the flood season from 15 July 2013 to 10 August 2013. The results showed the N2 O concentrations, the ratio of N2O/dinitrogen(N2) gases production, N2 O emission and denitrification rates ranged from 0.10 to 1.11 μg N/L,- 0.007% to 0.051%,- 9.73 to 127 μg N/m2/hr and 1.33 × 104to31.9 × 104μg N2/m2/hr, respectively, across the continuum. The average N2 O concentrations,the ratio of N2O/N2 and N2O emission was significantly lower in wetlands as compared to the rivers and lake(p 〈 0.01). The significantly high denitrification rate and low N2 O emission together highlighted that most N2 O can be converted into N2 via near complete denitrification in the Poyang Lake wetlands. Our study suggests that the wetlands might impact N2 O budget in an integrated aquatic ecosystems. Moreover, N2 O emission from different aquatic ecosystem should be considered separately when quantifying the regional budget in aquatic ecosystem. 展开更多
关键词 Nitrous oxide gas Nitrogen Dinitrogen gas DENITRIFICATION Natural wetlands poyang Lake
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Spatio-temporal difference analysis of cultivated land use intensity based on emergy in the Poyang Lake Eco-economic Zone of China 被引量:9
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作者 XIE Hualin HE Yafen +1 位作者 ZOU Jinlang WU Qun 《Journal of Geographical Sciences》 SCIE CSCD 2016年第10期1412-1430,共19页
Taking the emergy requirements of the five input indexes as the foundation, this paper analyzes the total temporal and spatial changes in cultivated land use intensity in the Poyang Lake Eco-economic Zone from 2000 to... Taking the emergy requirements of the five input indexes as the foundation, this paper analyzes the total temporal and spatial changes in cultivated land use intensity in the Poyang Lake Eco-economic Zone from 2000 to 2010. The results are obtained as follows: (1) Over a period of 10 years, the cultivated land use intensity has increased exponentially in the Poyang Lake Eco-economic Zone; agricultural machinery intensity has been the largest proportion of the total inputs, comprising more than 99.50% and increasing year by year, which indicates that agricultural mechanization is a basic trend in agricultural development in the Poyang Lake Eco-economic Zone. (2) The total number of counties belonging to the moderate- and low- intensity cultivated land use categories is the largest, while the number of counties belonging to the high-intensity cultivated land use and extensive cultivated land use categories is the smallest. (3) This zone can be divided into five areas: an eastern area of high-intensity cultivated land use, a central and eastern area of low-intensity cultivated land use, a central area of low-intensity cultivated land use, a southern area of moderate-intensity cultivated land use, and a northern area of moderate-intensity cultivated land use. (4) The counties which had a coordinated development between cultivated land use intensity and their socio-economic development level increase year by year, and the socio-economic development level had increasingly obvious effects on the cultivated land use intensity. Finally, this paper presents suggestions for the development of cultivated land use intensity in the Poyang Lake Eco-economic Zone, especially for different levels of intensity among counties. 展开更多
关键词 cultivated land land use intensive emergy term poyang Lake Eco-economic Zone
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Farmers' vulnerability to flood risk: A case study in the Poyang Lake Region 被引量:7
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作者 MA Dingguo CHEN Jie +2 位作者 ZHANG Wenjiang ZHENG Lin LIU Ying 《Journal of Geographical Sciences》 SCIE CSCD 2007年第3期269-284,共16页
This paper quantitatively explores farmers' vulnerability to flood in the Poyang Lake Region (PLR) with the supports of GIS spatial functions. The analysis consists of three major steps, which is based on the spati... This paper quantitatively explores farmers' vulnerability to flood in the Poyang Lake Region (PLR) with the supports of GIS spatial functions. The analysis consists of three major steps, which is based on the spatial unit of township. Firstly, the spatial extent and characteristics of flood risk areas were determined using a digital elevation model (DEM) derived from the 1:50,000 topographic map. Secondly, for each of the township, six indices indicating the economic activities of local farmers were calculated. These indices are: rural population proportion, cultivated land proportion, GDP per unit area, employment proportion of primary industry, net rural income per capita and agricultural income proportion. These six indices were then normalized and used for later vulnerability assessment. Thirdly, the normalized indices (as GIS data layers) were overlaid with the flood risk areas to produce the risk coefficient for each township and to calculate the overall vulnerability for each township. The analysis results show that in the PLR there are high flood risk areas where the farmers' livings are seriously influenced or threatened. About 55.56% of the total 180 townships in the flood risk areas have a high degree of flood vulnerability. The townships under flood risk are mainly distributed in the areas around the Poyang Lake and the areas along the "five rivers". 展开更多
关键词 flood risk FARMER vulnerabifity poyang Lake Region
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Simulation on phosphorus release characteristics of Poyang Lake sediments under variable water levels and velocities 被引量:6
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作者 TONG Yali LIANG Tao +1 位作者 WANG Lingqing LI Kexin 《Journal of Geographical Sciences》 SCIE CSCD 2017年第6期697-710,共14页
Since the construction of the Three Gorges Dam, the Poyang Lake hydrological characteristics obviously changed. During the impoundment period of the Three Gorges Reservoir, the hydrodynamic factors of Poyang Lake vari... Since the construction of the Three Gorges Dam, the Poyang Lake hydrological characteristics obviously changed. During the impoundment period of the Three Gorges Reservoir, the hydrodynamic factors of Poyang Lake varied. Water level dropped, the velocity decreased and water exchange time lengthened, which changed the release of phosphorous from sediments. In order to investigate how the hydrodynamic factors influence the release of phosphorous from sediments, we used a two-way annular flume device to simulate the release characteristics of phosphorous from sediments under variable water levels and velocities. We found that both water level rising and velocity increasing could enhance the distur- bance intensity to sediments, which caused the increase of suspended solids (SS) concentration, total phosphorus (TP) concentration in the overlying water, and the ability that phosphorus released to overlying water from sediments enhanced as well: when overlying water velocity maintained 0.3 m/s, SS concentration increased to 4035.85 mg/L at the water level 25 cm which was about 25 times compared to the minimum value and TP concentration in the overlying water also reached the maximum value at the water level 25 cm which was 1.2 times that of the value at 10 cm; when water level maintained 15 cm, SS concentration increased to 4363.35 mg/L at the velocity of 0.5 m/s which was about 28 times compared to the value of 0 m/s, and TP concentration in the overlying water increased from 0.11 mg/L to 0.44 mg/L. When the water level maintained 15 cm, the phosphorous release rate reached the maximum value of 4,86 mg/(md) at 0.4 m/s. The concentration of total dissolved phosphorous (TDP) and soluble reactive phosphate (SRP) both in overlying water and sediment-water interface were negatively correlated with pH. Using the parabolic equation, the optimum water level at a velocity of 0.3 m/s was calculated to be 0.57 cm, and the optimum velocity at water level of 15 cm was found to be 0.2 m/s. 展开更多
关键词 hydrodynamic factors sediment-water interface total phosphorous total dissolved phosphorous soluble reactive phosphate poyang Lake
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