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131.
In October 2000, the flow of the River Murray entering South Australia was increased from 32 000 to 42 050 ML day?1 by release of water from an offstream reservoir, and a downstream weir was raised by 500 mm to impound the flood and enhance local floodplain inundation. The flood was maintained for about two weeks, although the duration of inundation was longer at low elevations on the floodplain. Vegetation at three sites was surveyed before and after the flood to examine the impact of inundation on the growth and germination of flood‐tolerant, flood‐dependent and flood‐intolerant species. Among 32 recorded species, Atriplex vesicaria (bladder saltbush, Chenopodiaceae), Sporobolus mitchellii (rats tail couch, Graminae) and Sarcocornia quinqueflora (samphire, Chenopodiaceae) accounted for nearly 82% of the total cover/abundance. Flood‐tolerant and flood‐dependent species (e.g. S. mitchellii) grew and germinated and flood‐intolerant species (e.g. A. vesicaria) senesced. No aquatic plants germinated or established, despite favourable conditions, suggesting an impoverished seed bank or grazing. Based on the growth but lack of germination of flood‐tolerant and flood‐dependent species, the value of small, occasional interventions in environmental flow management may be to maintain existing communities rather than restore degraded ones. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
132.
We examined the impacts of remediation activities aimed at improving the water quality of hypereutrophic Villerest Reservoir, in which Microcystis aeruginosa dominated during the summer. We also compared nutrients and chlorophyll a data from this study with the results of a previous study on the reservoir. Between the two studies, the nitrogen and phosphorus loads into the reservoir from the main tributary decreased by 70% and 80%, respectively. Within the reservoir, the quantities of ammonia‐nitrogen were similar in the two studies, and the total nitrogen was significantly higher in this study compared to the initial study. Both the phosphate‐phosphorus and total phosphorus concentrations decreased significantly between the two studies. However, the statistically significant decrease in phosphate‐phosphorus and total phosphorus did not always lead to a significant decrease in chlorophyll a concentrations. The nitrogen/phosphorus mass ratio during the present study remained well above five, the critical value below which summer blooms of Microcystis aeruginosa were observed in Villerest Reservoir. These study results indicated that the remediation activities being used to improve the water quality of Villerest Reservoir were off to a good start.  相似文献   
133.
Aligning employees with the firm's larger strategic goals is critical if organizations hope to manage their human capital effectively and ultimately attain strategic success. An important component of attaining and sustaining this alignment is for employees to have a “line of sight” (LOS) with their organization's strategic objectives. In this article, we illustrate how the translation of calculated firm goals into tangible results requires that employees not only understand the organization's strategy, but also accurately appreciate what actions are aligned with realizing that strategy. Using recent empirical evidence, theoretical insights, and tangible examples of exemplary firm practices, we provide thought-leaders with a comprehensive view of LOS by showing how it can be created, how it can be enhanced or stifled, and how it can be effectively managed. Further, we integrate LOS with current thinking on employee alignment to help managers more effectively benefit from understanding human capital potential.  相似文献   
134.
The influence of stakeholders, organisational commitment, personal values, goals of the organisation and socio-demographic characteristics of individuals on the ethical dimension of behavioural intentions of employees in various organisations are investigated. The research results show that employees working for the public sector or in educational institutions take more ethical aspects into account than employees working in the "private" sector. The influence of stakeholders and organisational commitment do not significantly affect the ethical behaviour of employees, and only some personal values and goals of the organisation have a significant influence on ethical behaviour. The most significant explanatory factor of ethical decision making seems to be what may be called "stage in the career of the employee": "ethical" employees can be described as young, with a relatively low income, limited work experience and a low level of responsibility in the company.  相似文献   
135.
随着西藏"一江两河"地区人类活动的不断增加,水文断面所测的径流资料,在数量和时程分配上已不能代表河流的天然状况,在利用这些资料进行水资源评价及工程设计时,必须将实测径流还原为天然径流资料。根据该地区资料条件,雅鲁藏布江径流还原采用典型区法,先率定典型区的灌溉定额,并依据历年各水文站以上地区灌溉面积统计资料,计算还原水量,按典型区灌溉制度进行年内分配。  相似文献   
136.
人工湿地改善嘉兴市饮用水源地水质的研究   总被引:1,自引:1,他引:0  
针对水质型缺水的嘉兴地区,进行了人工湿地处理技术改善饮用水源地水质的探索。介绍了嘉兴市石臼漾水厂人工湿地一期工程的设计和运行工艺流程。工程实施后对水质进行了监测和分析,并对工程所带来的经济、社会、环境等综合效益进行了评估。分析结果表明,主要水污染物降低了一个类别,水厂进口水质基本达到了《国家地表水环境质量标准》(GB3838-2002)规定的Ⅲ类水标准,基本上实现了预期的目标。经过近一年的试运行表明,嘉兴市石臼漾水厂人工湿地一期工程基本上达到了预期的目标。对湿地运行存在的一些问题和不足进行了分析,提出了改进的措施和建议。  相似文献   
137.
韩国城市河流生态恢复的案例与经验   总被引:1,自引:0,他引:1  
通过介绍和分析韩国清溪川与光州川生态恢复的案例,在河流生态恢复的设计理念、技术方法等方面提出对我国城市河流治理的借鉴。认为只有把城市河流生态恢复作为系统工程,对城市河流进行多目标的恢复治理、将河流治理列入城市规划、分区域规划和建设、多学科开展研究和基础调查、营造动物栖息地、恢复河流自然功能才是城市河流生态恢复的归宿。  相似文献   
138.
天人合一是我国传统哲学中占主导地位的命题。儒家提倡“泛爱万物”和“仁爱自然”,道家提倡“见素抱朴”,“道法自然”,都体现了人与自然和谐的理念。中国古代文明至今延绵五千年,得益于对水土资源的珍惜和对于自然生态系统的保护。黄河是中华民族的摇篮,孕育了辉煌的中华文明。近半个世纪黄河流域经济发展和黄河治理的成绩为世人瞩目。可是。成就中隐藏着挑战,黄河巨变引发了生态危机。河流断流、水质污染、河流高度人工化和生物多样性下降,导致流域生态系统退化。近年来,黄河实施水量统一调度和调水调沙,对于遏制生态系统退化已经初见成效。河流生态修复的本质就是老子的“道法自然”。黄河生态修复任重道远,建议加强黄河生态监测网络建设;水文情势恢复;水污染防控;鱼类及栖息地保护;湿地保护和上游水电梯级开发规划论证等工作。  相似文献   
139.
衡水湖湿地生态系统恢复原理与方法   总被引:3,自引:2,他引:1  
由于衡水湖流域上游建设了大量水利工程,使衡水湖入湖水量逐年减少,最终导致干涸。自2000年河北省政府批准建立衡水湖省级自然保护区,由外流域调水与本地水资源联合调度水资源,开始实施对衡水湖湿地的恢复。通过对衡水湖湿地生态系统恢复的原则、原理和方法进行分析,衡水湖湿地生态恢复方法采用外流域调水补充水源、利用水生植物控制湿地营养物质的措施、利用种子库、植物繁殖体等途径恢复植被等措施。确定恢复目标为恢复湿地功能、保护野生动物、恢复传统景观等,并对恢复后的衡水湖生物多样性进行评价,探讨湿地恢复过程中的具体问题,为北方干旱地区湿地生态恢复提供参考依据。  相似文献   
140.
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