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961.
Telemetry observations of predation and migration behaviour of brown trout (Salmo trutta) smolts negotiating an artificial lake 下载免费PDF全文
Michael Schwinn Henrik Baktoft Kim Aarestrup Martyn C. Lucas Anders Koed 《河流研究与利用》2018,34(8):898-906
Eutrophication of coastal areas as a consequence of the agricultural use of fertilizers is a widespread problem. The development of artificial lakes and constructed wetlands in nutrient‐rich rivers is a widely used management tool in the fight to decrease eutrophication. Juvenile salmonids that have to negotiate these lakes during their downstream migration to the sea are commonly subjected to high mortality due to increased predation pressure and delayed passage. In this study, we double tagged 39 brown trout smolts with passive integrated transponder and radio tags to gain further insight into predation rates and migration patterns during their passage of an artificial lake in a Danish lowland stream in the spring of 2016. Thirty‐four of the tagged smolts, caught and released upstream, entered the lake, of which 22 (65%) successfully exited the lake. Four smolts (12%) returned upstream to the river. Three smolts were predated in the lake by two northern pike (Esox lucius). Three tags were recovered from the lake bottom, and two disappeared out of the study area after a last detection in the lake. Tracking the smolts manually and by automatic listening stations showed highly erratic movement patterns during lake passage. Further, we observed long delays of up to 27 days after the smolts reached the river mouth and before they entered the sea, potentially due to low sea water temperature or due to the stocking of a large amount of hatchery‐reared brown trout smolts. The results are discussed in the context of abiotic and biotic factors, which differed considerably in the year 2016 compared with previous years. 相似文献
962.
Socio‐economic and institutional assessment of Malaysia's first biosphere reserve: Chini Lake 下载免费PDF全文
Zati Sharip Akashah Majizat Saim Suratman 《Lakes & Reservoirs: Research and Management》2018,23(2):104-116
Despite being designated the first UNESCO Biosphere Reserve in Malaysia, the Chini Lake Basin experiences continuing management challenges attributable to existing sectoral management practices and differences in demands of multiple stakeholders. Accordingly, a socio‐economic survey and stakeholder consultative process were undertaken, involving relevant stakeholders in the lake basin. The consultative process involved: (a) identification and prioritization of relevant stakeholders; (b) assessment of their socio‐economic activities and perceptions; (c) organization of focus group discussions between basin stakeholders; and (d) development of management recommendations in collaboration with stakeholders. The results of this study indicated the local community's way of living has changed from traditional occupations to a wage economy. Overlapping functions and lack of communication were among the major identified challenges facing by Chini Lake. Multiple strategies were proposed to promote environmental protection and good governance of Chini Lake, including formation of special area plans and strengthening institutional arrangements to sustainably manage the Chini Lake catchment. An effective authority also is necessary to improve communication and coordination of programmes by the various basin agencies and communities. 相似文献
963.
东平湖老湖区生态环境需水量研究 总被引:3,自引:2,他引:1
东平湖既是防御黄河下游大洪水的重要分滞洪区,又是南水北调东线最末一级调度湖泊,具有防洪、调水、航运、旅游、养殖、引水灌溉等多项功能,其中老湖区是其发挥各项功能的基础。基于东平湖的功能,分别计算其本底需水量、蒸散发需水量、渗漏需水量、水生生物栖息地需水量、景观娱乐需水量、稀释净化需水量、航运需水量,并综合考虑湖泊内生态和环境影响因子,建立生态环境需水量优化计算模型,对东平湖老湖区生态环境需水量进行了计算。结果表明:东平湖老湖区的适宜生态环境需水量为2.75亿m3,对应的适宜水位为41.20 m。 相似文献
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966.
基于对荷兰艾瑟尔湖流域水污染防治历程及其水管理措施详细梳理的基础上,对艾瑟尔湖与太湖从源头控污、末端治理、管理体制、立法、经济激励机制及区域合作等方面进行分析比较。根据艾瑟尔湖流域在污水处理、流域水资源管理、生态环境恢复、监督合作治污体制建设等领域所取得的成功经验与启示,指出太湖流域水污染治理及管理的各个层次与艾瑟尔湖流域仍存在一定差距,建议太湖流域在治理过程中加强初期雨水的监测与截留处理,将部分典型持久性有毒有机污染物纳入监测范围,对污水处理产生的污泥进行深度处理,推进流域联动治污机制的建设,探索适合中国国情的水资源市场经济激励机制。 相似文献
967.
风场是影响湖泊水动力的重要因素,它可以改变水体运动速度和方向,影响各种物质在湖泊内的输移扩散。通过分析博斯腾湖大湖区风场,准确估算出风力、风向变化情况,构建了博斯腾湖平面二维水动力模型。应用计算模型对博斯腾湖水动力进行模拟预测,分析不同风向、风速对湖泊流场结构的影响,为进一步研究博斯腾湖水动力和污染物输移扩散提供理论依据。 相似文献
968.
首先对查干湖的主要水源补给进行了量化分析,分析其水量平衡关系,探究查干湖水源保障措施。其水源补给包括霍林河、深重涝区的来水,以及前郭灌区、地下水量和地表径流来水总量,水量流失主要为蒸发量、植物蒸腾及地下渗漏,量化分析其平衡关系。最后,提出具有针对性的补水和改善水质的主要工程措施及解决办法,为有效提升查干湖的生态功能提供参考。 相似文献
969.
河湖水系连通是提高水资源配置能力、增强抵御旱涝灾害能力和改善生态环境的重要战略举措,而如何对河湖水系连通的影响进行评价,是相关部门开展河湖水系连通决策和管理时迫切需要解决的问题。本文建立了包含社会、经济及生态环境等3个方面共23个指标的河湖水系连通影响评价指标体系,探讨了河湖水系连通影响评价的独特特征,指出在一般情况下对连通的影响需要在单区域(调水区或受水区)和整个连通区上分两个层面进行评价,从而评价指标可能在两个层面上都存在阈值,初步讨论了各单指标的评价方法。 相似文献
970.
To meet the increasing need of fresh water and to improve the water quality of Taihu Lake, water transfer from the Yangtze River was initiated in 2002. This study was performed to investigate the sediment distribution along the river course following water transfer. A rainfall-runoff model was first built to calculate the runoff of the Taihu Basin in 2003. Then, the flow patterns of river networks were simulated using a one-dimensional river network hydrodynamic model. Based on the boundary conditions of th... 相似文献