917 resultados para Three Gorges Project
Resumo:
自然界木本植物在某些情况下可能面对淹水带来的胁迫伤害,木本植物对淹水的生理生态响应及适应机制的研究,不仅可以从机理上解释河岸带和消落区树种分布的规律,对于大型水库消落区的治理也能起到理论依据的作用,因此,木本植物对淹水的生理生态响应及适应机制历来是植物生理生态研究领域的热点问题之一。 三峡水库蓄水造成库区部分陆地岛屿化,这将对岛屿优势植物带来深远影响。短柄枹栎(Quercus glandulifera)、栓皮栎(Quercus variabilis)、马尾松(Pinus massoniana)是这些岛屿上的三种优势树种。在岛屿形成初期,应用生理生态学手段,在7月和9月分别对其水势和叶绿素荧光进行了野外测定,从而为岛屿化对植物生理生态影响的研究和监测提供重要的本底数据。研究结果表明马尾松较其它两种植物更耐旱。水势和Fv/Fm在清晨高中午低,经过一个晚上可以基本恢复,因此就目前状况看岛上的三种优势植物均生长健康。但是库区蓄水后,在淹水胁迫下植物的生理生态过程将如何变化,还需要后期的连续观测。 枫杨(Pterocarya stenoptera)、池杉(Taxodium ascendens)和栓皮栎(Quercus variabilis)是三峡库区河岸带和库塘消落区常见的植物,对于河岸带和库塘消落区的水土保持和水源涵养具有十分重要的作用。通过设计模拟淹水实验,研究了这三种植物对淹水的生理生态响应及适应机制。淹水对枫杨和栓皮栎生理生态过程的早期影响是快速降低了二者的最大净光合速率、气孔导度、最大光化学量子效率(Fv/Fm)。但经过最初的下降后,枫杨的最大净光合速率、气孔导度和最大光化学量子效率逐渐恢复,而栓皮栎的则持续下降。在试验过程中,枫杨和池杉均产生了有利于吸收氧气的不定根和肥大的皮孔,而栓皮栎没有产生不定根。随淹水时间的增加枫杨的叶绿素含量与对照没有显著差异;而栓皮栎的叶绿素含量在第33天后大幅降低,Chla/Chlb的比值下降。淹水后第10天和70天测定的清晨水势,受淹栓皮栎比对照高,而受淹枫杨比对照低。淹水导致池杉和栓皮栎的根/茎/叶膜质过氧化状态均呈现动态变化。淹水处理的栓皮栎根的MDA含量低于对照而池杉的高于对照,比如:淹水24天后,栓皮栎根的丙二醛含量是对照的73%;而池杉是对照的111.5%。淹水处理第10天和第24天两个种的叶和茎MDA含量均高于对照但第50天则略低于对照。淹水导致池杉和栓皮栎两个种的根/茎/叶可溶性糖含量呈现动态变化。持续淹水导致栓皮栎叶片可溶性糖含量相比于对照先略下降后上升,茎可溶性糖含量显著上升而根可溶性含量先下降后上升。而池杉根/茎/叶可溶性糖含量对照和处理之间差异不显著。淹水导致栓皮栎的比叶重(Leaf dry mass per area)持续升高,池杉的与对照没有显著差异。淹水导致栓皮栎的根系活力持续下降,池杉则开始时下降后又升高,这可能与池杉在淹水过程中产生了有利于吸收氧气的不定根,而栓皮栎没有产生不定根有关。 以上生理生态的实验结果说明相对枫杨和池杉,栓皮栎应属于对淹水较敏感的树种。并得到以下一些结论:1)间接支持了“长期淹水导致不耐淹种(如栓皮栎)库量减小,进而导致光合速率下降的负反馈效应”假说;2)淹水对不耐淹种光合速率下降的影响至少包括气孔开度降低、光化学量子效率降低和库尺寸下降导致的光合速率下调的负反馈效应(长期)三个生理生态原因;3)淹水对水势的影响与树种相关;4)淹水并未导致不耐淹种(如栓皮栎)根膜质过氧化状态上升,而是导致其下降。导致其下降的主要原因是根系缺氧造成的;5)淹水胁迫初期耐淹种(如枫杨和池杉)和不耐淹种(栓皮栎)均出现部分生理生态过程的下调,持续时间大概在1-10天内。随后耐淹种生理过程逐渐恢复而不耐淹种在略为恢复1-2天后逐渐下降到较低水平。耐淹种恢复的关键原因可能是不定根和肥大的皮孔的出现。 令人意外的是70天的淹水过程并没有导致栓皮栎的死亡,这说明该树种对淹水具有一定的忍耐能力。因此,栓皮栎分布于河岸带和消落区较高海拔处并很少受到季节性淹水影响的生理生态原因可能还包括其他方面。淹水后可能要面对土壤透气性恢复带来的生理干旱胁迫可能对栓皮栎的生理过程造成影响。因此进一步研究淹水后恢复过程中三个种的生理生态过程对于深刻理解河岸带和消落区树种分布的生理生态原因无疑具有十分重要的理论意义。
Resumo:
The numbers of spawning sites for Chinese sturgeon have been drastically reduced since the construction of the Gezhouba Dam across the Yangtze River. This dam has blocked migration of Chinese sturgeon to their historic spawning ground causing a significant decline of the Chinese sturgeon population. We conducted a VORTEX population viability analysis to estimate the sustainability of the population and to quantify the efficiency of current and alternative conservation procedures. The model predicted the observed decline of Chinese sturgeon, resulting from the effect of the Gezhouba Dam. These simulations demonstrated the potential interest of two conservation measures: increasing spawning area and reducing predation on sturgeon eggs. The simulations also demonstrated that the actual restocking program is not sufficient to sustain sturgeon population as the artificial reproduction program induce the loss of more wild mature adults that the recruitment expected by the artificial reproduction.
Two spawning stocks of icefish Neosalanx taihuensis revealed from annual reproductive cycle analyses
Resumo:
Neosalanx taihuensis were sampled from the Tian-e-zhou Oxbow from March 2006 through November 2007. Two separate spawning seasons were identified based on the annual reproductive cycles of the females, designated as the autumn-spawning season and the spring-spawning season. Lifespan of the offspring of the spring-spawning fish was 1 year, with them dying after the subsequent spring spawning. Autumn-spawned females seem to be the offspring of the spring-spawning fish, based on monthly changes in the length-frequency distributions. Spring-mature females had higher absolute fecundity, gonadosomatic index, and relative condition factor in 2007 than in 2006. Relative condition factor of the immature female offspring of spring-spawning fish was higher in 2007 than in 2006, portending a further increase in reproductive investment during the spring spawning of 2008. The increasing reproductive investment suggests that the population of N. taihuensis in the Tian-e-zhou Oxbow may be recovering from its recent decline.
Resumo:
P>A sampling system for capturing sturgeon eggs using a D-shaped bottom anchored drift net was used to capture early life stages (ELS) of Chinese sturgeon, Acipenser sinensis, and monitor annual spawning success at Yichang on the Yangtze River, 1996-2004, before and just after the Three Gorges Dam began operation. Captured were 96 875 ELS (early life stages: eggs, yolk-sac larvae = eleuthero embryos, and larvae); most were eggs and only 2477 were yolk-sac larvae. Most ELS were captured in the main river channel and inside the bend at the Yichang spawning reach. Yolk-sac larvae were captured for a maximum of 3 days after hatching began, indicating quick dispersal downstream. The back-calculated day of egg fertilization over the eight years indicated a maximum spawning window of 23 days (20 October-10 November). Spawning in all years was restricted temporally, occurred mostly at night and during one or two spawning periods, each lasting several days. The brief temporal spawning window may reduce egg predation by opportunistic predators by flooding the river bottom with millions of eggs. During 1996-2002, the percentage of fertilized eggs in an annual 20-egg sample was between 63.5 to 94.1%; however, in 2003 the percentage fertilized was only 23.8%. This sudden decline may be related to the altered environmental conditions at Yichang caused by operation of the Three Gorges Dam. Further studies are needed to monitor spawning and changes in egg fertilization in this threatened population.
Resumo:
The objective of this study was to illustrate the phylogenetic relationship of the species in the genus Craspedacusta in China. The medusae samples were collected at 28 localities in China representing seven described species with their entire ITS region (the contiguous sequences of ITS-1, 5.8S and ITS-2 rDNA) rDNA sequences cloned. Among the 28 samples, the range of sequence variation in the complete ITS and 5.8S region was between 0 and 36.2%. Three main clades were revealed by both maximum likelihood and neighbour-joining trees, with sequence difference of 0-0.9, 0-3.7 and 0.1-1.5% in the three clades. The nesting of C. xinyangensis representatives within C. sowerbii, C. brevinema within C. sinensis and C. sichuanensis within C. kiatingi is strongly supported, with interspecific sequence divergence of 0-0.9, 0.1-1.4 and 0.0-0.4%, respectively. Thus, it is suggested that C. xinyangensis should be the synonym of C. sowerbii, C. sichuanensis the synonym of C. kiatingi and C. brevinema the synonym of C. sinensis. However, the taxonomic status of C. ziguiensis is still uncertain. According to the tree topology, C. kiatingi was closer to C. sowerbii than to C. sinensis. Craspedacusta sinensis was the most genetically distinct from distance matrix values, and located at the base of the phylogenetic trees, so it can be speculated that the C. sinensis may be the ancestral form in the genus Craspedacusta.
Resumo:
A collection of 577 Coilia mystus was made during April 2006 and 2007 from China's Yangtze Estuary to estimate the age structure and growth patterns of the population. Examination of sectioned sagittal otoliths revealed a periodic straight/curved growth pattern. The straight zone was from April to November, and the curved zone from October to May, indicating annual periodicity. Annual periodicity was also verified by margin zone analysis. The shift from a curved-zone to the next straight-zone stanza was defined as an annulus. The fish from which the otoliths were taken were 0-5 years old. The von Bertalanffy growth function was fitted to standard length (LS)-at-age data as L-S = 215.16 (1 - e(-0.53(t+0.30))) (n = 577, r(2) = 0.81, p < 0.05). The mature females included five age classes, ages 1 and 2 accounting for 74.3% of the population. The mature males included fish aged 1 and 2, those at age 1 accounting for 86.4% of the population. Mean length was smaller, and annual growth less, for mature males than for females of comparable age. The study demonstrated that the Yangtze population of C. mystus consists of more age classes than previously thought and that the age structure of the population needs to be considered in management decisions.
Resumo:
The natural reproduction of grass carp, black carp, silver carp, and bighead will be affected adversely by the Three Gorges Project in the Yangtze River. One of the methods to save the fish is to regulate the water levels, keeping them suited for the species to spawn. Nine factors associated with the scale of larvae-flood of the four species are classified into five levels, and the ranges of these factors producing larvae-floods are given by using the "factor-criteria system reconstruction analysis" method. Moderate beginning water levels and flow, with high daily increases in the rate of water level and flow, and a long duration of water level rising are important for the production of a large larvae-flood.
Resumo:
Guangxi Longtan Hydropower Station is not only a representative project of West Developing and Power Transmission from West to East in China, but also the second Hydropower Station to Three Gorges Project which is under construction in China. There are 770 X 104m3 creeping rock mass on the left bank slope in upper reaches, in which laid 9 water inlet tunnels and some underground plant buildings. Since the 435m high excavated slope threatens the security of the Dam, its deformation and stability is of great importance to the power station.Based on the Autodesk Map2004, Longtan Hydropower Station Monitoring Information System on Left Bank has been basically finished on the whole. Integrating the hydropower station monitoring information into Geographic Information System(GIS) environment, managers and engineers can dynamically gain the deformation information of the slop by query the symbols. By this means, designers can improve the correctness of analysis, and make a strategic and proper decision. Since the system is beneficial to effectively manage the monitoring-data, equitably save the cost of design and safe construction, and decrease the workload of the engineers, it is a successful application to the combination of hydropower station monitoring information management and computer information system technology.At the same time, on the basis of the geological analysis and rock mass toppling deformation and failure mechanism analysis of Longtan engineering left bank slope, the synthetic space-time analysis and influence factors analysis on the surface monitoring data and deep rock mass monitoring data of A-zone on left bank slope are carried on. It shows that the main intrinsic factor that effects the deformation of Zone A is the argillite limestone interbedding toppling structure, and its main external factors are rain and slope excavation. What's more, Degree of Reinforcement Demand(DRD) has been used to evaluate the slop reinforce effect of Zone A on left bank according to the Engineering Geomechanics-mate-Synthetics(EGMS). The result shows that the slop has been effective reinforced, and it is more stable after reinforce.At last, on the basis of contrasting with several forecast models, a synthetic forecast GRAV model has been presented and used to forecast the deformation of zone A on left bank in generating electricity period. The result indicates that GRAV model has good forecast precision, strong stability, and practical valuable reliability.
Resumo:
The QUT Outdoor Worker Sun Protection (OWSP) project undertook a comprehensive applied health promotion project to demonstrate the effectiveness of sun protection measures which influence high risk outdoor workers in Queensland to adopt sun safe behaviours. The three year project (2010-2013) was driven by two key concepts: 1) The hierarchy of control, which is used to address risks in the workplace, advocates for six control measures that need to be considered in order of priority (refer to Section 3.4.2); and 2) the Ottawa Charter which recommends five action means to achieve health promotion (refer to Section 2.1). The project framework was underpinned by a participatory action research approach that valued peoples’ input, took advantage of existing skills and resources, and stimulated innovation (refer to Section 4.2). Fourteen workplaces (small and large) with a majority outdoor workforce were recruited across regional Queensland (Darling Downs, Northwest, Mackay and Cairns) from four industries types: 1) building and construction, 2) rural and farming, 3) local government, and 4) public sector. A workplace champion was identified at each workplace and was supported (through resource provision, regular contact and site visits) over a 14 to 18 month intervention period to make sun safety a priority in their workplace. Employees and employers were independently assessed for pre- and postintervention sun protection behaviours. As part of the intervention, an individualised sun safety action plan was developed in conjunction with each workplace to guide changes across six key strategy areas including: 1) Policy (e.g., adopt sun safety practices during all company events); 2) Structural and environmental (e.g., shade on worksites; eliminate or minimise reflective surfaces); 3) Personal protective equipment (PPE) (e.g., trial different types of sunscreens, or wide-brimmed hats); 4) Education and awareness (e.g., include sun safety in inductions and toolbox talks; send reminder emails or text messages to workers);5) Role modelling (e.g., by managers, supervisors, workplace champions and mentors); and 6) Skin examinations (e.g., allow time off work for skin checks). The participatory action process revealed that there was no “one size fits all” approach to sun safety in the workplace; a comprehensive, tailored approach was fundamental. This included providing workplaces with information, resources, skills, know how, incentives and practical help. For example, workplaces engaged in farming complete differing seasonal tasks across the year and needed to prepare for optimal sun safety of their workers during less labour intensive times. In some construction workplaces, long pants were considered a trip hazard and could not be used as part of a PPE strategy. Culture change was difficult to achieve and workplace champions needed guidance on the steps to facilitate this (e.g., influencing leaders through peer support, mentoring and role modelling). With the assistance of the project team the majority of workplaces were able to successfully implement the sun safety strategies contained within their action plans, up skilling them in the evidence for sun safety, how to overcome barriers, how to negotiate with all relevant parties and assess success. The most important enablers to the implementation of a successful action plan were a pro-active workplace champion, strong employee engagement, supportive management, the use of highly visual educational resources, and external support (provided by the project team through regular contact either directly through phone calls or indirectly through emails and e-newsletters). Identified barriers included a lack of time, the multiple roles of workplace champions, (especially among smaller workplaces), competing issues leading to a lack of priority for sun safety, the culture of outdoor workers, and costs or budgeting constraints. The level of sun safety awareness, knowledge, and sun protective behaviours reported by the workers increased between pre-and post-intervention. Of the nine sun protective behaviours that were assessed, the largest changes reported included a 26% increase in workers who “usually or always” wore a broad-brimmed hat, a 20% increase in the use of natural shade, a 19% increase in workers wearing long-sleeved collared shirts, and a 16% increase in workers wearing long trousers.
Resumo:
In this paper, we develop two stakeholder relationships scales. These scales assess project managers’ perceived competence in establishing and maintaining high quality, effective relationships with people internal to the project as well as those stakeholders who are external to the project. We developed the scales using an online survey study of three hundred and seventy three complex project managers from a sub-set of the Australian Defence Industry. Both the internal stakeholder relationships’ scale and the external stakeholder relationships’ scale demonstrated validity and reliability. This research has implications for the interpersonal work relationships’ literature and the stakeholder management literature. We recommend future research tests these scales with multiple samples, across different project types and project industries. The stakeholder relationships’ scales should be versatile enough to be applied to project management generally but are best suited to large-scale complex project environments.
Resumo:
The anadromous Chinese sturgeon (Acipenser sinensis), mainly endemic to the Yangtze River in China, is an endangered fish species. The natural population has declined since the Gezhouba Dam blocked its migratory route to the spawning grounds in 1981. In the near future, the completion of the Three Gorges Dam, the world's largest hydroelectric project, may further impact this species by altering the water flow of the Yangtze River. Little is currently known about the population genetic structure of the Chinese sturgeon. In this study, DNA sequence data were determined from the control region (D-loop) of the mitochondrial genome of adult sturgeons (n = 106) that were collected between 1995-2000. The molecular data were used to investigate genetic variation, effective female population size and population history of the Chinese sturgeon in the Yangtze River. Our results indicate that the reduction in abundance did not change genetic variation of the Chinese sturgeon, and that the population underwent an expansion in the past. AMOVA analysis indicated that 98.7% of the genetic variability occurred within each year's spawning populations, the year of collection had little influence on the diversity of annual temporary samples. The relative large effective female population size (N-ef) indicates that good potential exists for the recovery of this species in the future. Strikingly, the ratio of N-ef to the census female population size (N-f) is unusually high (0.77-0.93). This may be the result of a current bottleneck in the population of the Chinese sturgeon that is likely caused by human intervention.
Resumo:
Chongqing is the largest directly-controlled municipality in China, which is now undergoing a rapid urbanization. The urbanization rate increased from 35.6% in 2000 to 48.3% in 2007, and it is estimated to reach at least 70% by 2020. The question remains open: What are the consequences of such rapid urbanization in Chongqing in terms of urban microclimate? Furthermore, Chongqing is located within the Three Gorges Reservoir (TGR) region and the upper Yangtze River, where the Three Gorges Reservoir (TGR) project started in 1993 and was completed in 2010. As one of the biggest construction projects in the world with a rising water level of 175m and water storage capacity of about 39.3 billion m3, it would be interesting to investigate how such a gigantic project impacts the surrounding micro-environment, especially in Chongqing. Different research approaches are adopted in the study. Our literature review indicates present studies on the urban climate in Chongqing are mainly confined within the historical trend analysis of several weather stations operated by the Chongqing government, little is known about the spatial distribution of urban air temperature and how the local land cover influences the air temperature, especially when there are rivers running through the Chongqing urban area. To contribute to the present knowledge, a series of field measurement campaigns and numerical simulations were carried out. Two complementary types of field measurements are included: fixed weather stations and mobile transverse measurement. Numerical simulations using a house-developed program are able to predict the urban air temperature in Chongqing.
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"The first two years of this three year project were undertaken as Cooperative Research Project 6399, by Vanderbilt University and the U.S. Office of Education."
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Despite some segments of the creative industries in Australia performing better than other segments in terms of earnings and employment growth, they all rely on highly skilled workers and face similar workforce challenges. Workers typically experience multiple entry attempts, spells of unemployment, short-term contracts, high degrees of mobility, casual/part-time employment within and outside the creative industries, and pressure to ensure their skills remain relevant. Skills shortages and gaps, an insufficient supply of high quality industry-ready graduates, difficulties in predicting demand for skills, weak linkages between industry and education providers, reliance on overseas talent in some segments, limited opportunities for workers to engage in skill development, and pressure on workers to keep abreast of technological developments are ongoing issues in the creative industries workforce. In response to these concerns, the Australian Research Council, three State Governments, industry, and a large vocational education and training (VET) provider funded Queensland University of Technology (QUT) to conduct the 60Sox project. This three-year project investigated the education, training, and work experiences of aspiring creatives defined as new entrants, recent graduates, and students enrolled in creative industries courses. It involved the largest survey of aspiring creatives ever undertaken in Australia, attracting 507 respondents, and a survey of 50 employers. Using the framework proposed by Hannan, Raffe, and Smyth (1996), this article presents findings from an analysis of the macro and micro labour market outcomes of aspiring creatives using data from the two 60Sox project surveys and publicly available sources. The analysis confirmed that many graduates of creative industries courses who participated in the 60Sox survey and the national surveys for the National Centre for Vocational Education Research and Graduate Careers Australia were struggling to make a successful transition from education to work. This article also discusses the causes of this key finding and possible solutions to address transition issues.
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The Reporting and Reception of Indigenous Issues in the Australian Media was a three year project financed by the Australian government through its Australian Research Council Large Grants Scheme and run by Professor John Hartley (of Murdoch and then Edith Cowan University, Western Australia). The purpose of the research was to map the ways in which indigeneity was constructed and circulated in Australia's mediasphere. The analysis of the 'reporting' element of the project was almost straightforward: a mixture of content analysis of a large number of items in the media, and detailed textual analysis of a smaller number of key texts. The discoveries were interesting - that when analysis approaches the media as a whole, rather than focussing exclusively on news or serious drama genres, then representation of indigeneity is not nearly as homogenous as has previously been assumed. And if researchers do not explicitly set out to uncover racism in every text, it is by no means guaranteed they will find it1. The question of how to approach the 'reception' of these issues - and particularly reception by indigenous Australians - proved to be a far more challenging one. In attempting to research this area, Hartley and I (working as a research assistant on the project) often found ourselves hampered by the axioms that underlie much media research. Traditionally, the 'reception' of media by indigenous people in Australia has been researched in ethnographic ways. This research repeatedly discovers that indigenous people in Australia are powerless in the face of new forms of media. Indigenous populations are represented as victims of aggressive and powerful intrusions: ‘What happens when a remote community is suddenly inundated by broadcast TV?’; ‘Overnight they will go from having no radio and television to being bombarded by three TV channels’; ‘The influence of film in an isolated, traditionally oriented Aboriginal community’2. This language of ‘influence’, ‘bombarded’, and ‘inundated’, presents metaphors not just of war but of a war being lost. It tells of an unequal struggle, of a more powerful force impinging upon a weaker one. What else could be the relationship of an Aboriginal audience to something which is ‘bombarding’ them? Or by which they are ‘inundated’? This attitude might best be summed up by the title of an article by Elihu Katz: ‘Can authentic cultures survive new media?’3. In such writing, there is little sense that what is being addressed might be seen as a series of discursive encounters, negotiations and acts of meaning-making in which indigenous people — communities and audiences —might be productive. Certainly, the points of concern in this type of writing are important. The question of what happens when a new communication medium is summarily introduced to a culture is certainly an important one. But the language used to describe this interaction is a misleading one. And it is noticeable that such writing is fascinated with the relationship of only traditionally-oriented Aboriginal communities to the media of mass communication.