基于人水和谐的城市污水河流生态治理

文章在简述城市污水河流概况的基础上,介绍了城市污水河流目前存在的问题。针对城市污水河流五大问题,以人水和谐为指导,本着统一规划,综合治理,按照改善环境与防洪排水相结合、维护自然生态与满足行洪排水要求相结合、生态湿地与滞洪蓄洪相结合的三大原则,给出相应的五大建议措施。城市污水河流水系实施生态治理不仅对城市发展主题具有巨大的提升和促进作用,而且将有助于改善当地的水体环境和沿河的投资环境,促进该地区社会、经济的可持续发展,实现人水和谐,为城市污水河流改善治理提供参考。     

Morphological Similarity of Channels: From Linear Erosional Features (Rill,Gully) to Alpine Rivers

The geometric characteristics of incised features such as channels, rills, ephemeral gully, gully, represent the erosional transport regime and the fluvial dynamic equilibrium, and thus it is critical for the understanding of the long‐term evolution of natural, agricultural, and anthropogenic landscapes. This paper examines the morphological similarity of channelized erosion in two different environments such as Alpine landscapes and cultivated hillslopes. The first dataset comprises six rivers in the Italian Alps, three in the Carnia region and three in the Dolomites, where erosion is mainly the effect of discharges with high sediment loads or landslides and debris flows. The agricultural areas dataset includes rills, ephemeral gullies, and gullies surveyed in literature. This research highlights that the eroded volume in Alpine rivers is in line with that of agricultural landscapes or badlands around the world. Dolomites rivers of colluvial origin, flowing on soils that are not particularly deep and subject to natural disaggregation, tend to behave similarly to ephemeral gullies. Contrarily, channels that exhibit evident alluvial morphologies and coarse grain sizes are more similar to gully erosion. At different spatial scales, the results demonstrated that length–volume equations calibrated on rills, ephemeral gullies, gullies and badlands, might be feasible also for Alpine channels. The research areas present soils and bedrock lithology that differs from those in literature, thus suggesting that the morphology of linear erosion is independent of the intrinsic soil characteristics. Differences emerged between Dolomites and Carnia rivers: this highlights the importance of taking into account in future analyses other forcing factors (e.g. climate) on land degradation processes. Copyright © 2017 John Wiley & Sons, Ltd.     

喀斯特地区典型城市河流多自然特性评价体系研究

目前,针对喀斯特地区的多自然型河流治理研究较少,而喀斯特地区城市河流生态环境问题更为突出,生态环境更为敏感、更加脆弱,对此开展研究具有重要意义。本文在分析现有河流多自然特性评价体系、喀斯特地区河流特点的基础上,研究建立了喀斯特地区典型城市河流多自然特性评价体系,评价体系包含3个层次5大类19个评价指标,首次提出的5个重要评价指标权系数排名均在前10位,说明本体系更加完善,补充了以往研究中遗漏的重要评价指标。研究通过案例对比分析,表观多自然特性较好河段多自然特性量化评价分值明显高于表观多自然特性较差河段,进一步检验了评价指标体系的有效性、合理性、适用性。     

The importance of being natural in a human‐altered riverscape: role of wetland type in supporting habitat heterogeneity and the functional diversity of vegetation

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城市河流综合治理与生态建设探讨

【目的】通过对城市河流综合治理与生态建设的探讨,使社会各界更加重视和重新认识城市河流综合治理与生态建设的意义和发展方向。【方法】通过查阅大量国内外相关资料,运用分析归纳的方法对城市河流综合治理与生态建设进行了探讨。【结果】指出了我国城市河流综合治理与生态建设有利于改善城市居民的生存环境,促使生态型城市的形成,促进城市产业结构的合理调整和城市经济的发展;提出了我国城市河流综合治理与生态建设的发展方向,即应以环境生态建设为中心,重视城市河流的多种功能,遵循河流的自然规律,恢复河流的生命力和环境自净能力,使其向自然化、生态化、人文化、景观化发展。【结论】城市建设者应重视城市河流的生态、环境、景观和历史文化内涵建设,研究新一代河流综合治理与生态建设工程技术,实现管理制度的创新。     

补水对采金废弃矿区恢复效益的影响

以阿勒泰两河源自然保护区采金废弃矿区为研究对象,从地形、水、土和生物多方面开展矿山生态恢复试验,分析了推平、覆土、撒羊粪、水分补给、补植、撒种、羊群驻扎和漫溢措施对矿区植被的影响,结合每种措施的成本,选出恢复成效好、成本低的措施。结果显示,1)对废弃矿区进行人工灌溉后,物种数增加了21.7倍,土石比增加了4.5倍;2)滴灌、漫灌和喷灌3种措施中,漫灌措施下成效最好,对土壤的恢复中:覆土后,漫灌下的土石比分别较滴灌与喷灌高38.0%和33.1%;撒羊粪后,分别高出21.7%和11.4%;撒种后,分别高8.9%和8.5%;补植种黑加仑(Ribes nigrum)后,分别高24.2%和2.9%;3)不同灌溉方式下成本高低为滴灌喷灌漫灌,其中漫灌受地理位置限制,而喷灌则适用性广泛。阿勒泰矿山恢复中,可注重矿区的自然恢复并辅以漫灌和人工覆土等措施。本研究为其废弃矿区修复提供了一定的理论依据。     

Inter-calibration of three electric fishing techniques to estimate 0+ juvenile fish densities on sandy river beaches

Abstract  The efficiencies of three different techniques for 0+ fish point abundance sampling by electric fishing were tested on a sandy beach of the Morava River, Czech Republic. During direct electric fishing (DE), the operator immerses an anode fastened on an extension pole. During thrown anode electric fishing (TE), the anode is thrown at a distance from the bank. During remote electric fishing (RE), a pre-positioned anode is activated after allowing sufficient time for fish to recolonise the area. The DE technique was found to disturb fish and that fish tend to escape, thereby reducing its efficiency (30% of efficiency of RE). There was no significant difference in relative abundance estimates or size structure of assemblages between DE and RE, but TE seemed to be a species selective technique on sandy river beaches, significantly overestimating relative abundance of bleak. Of the three techniques tested, RE was the most efficient and if time required for deployment could be reduced, it would be also the most suitable for monitoring 0+ fish assemblages on sandy river beaches.     

Fishery yields vary with land cover on the Amazon River floodplain

Inland fisheries underpin food security in many tropical countries. The most productive inland fisheries in tropical and subtropical developing countries occur in large river–floodplain systems that are often impacted by land cover changes. However, few studies to date have assessed the effects of changes in floodplain land cover on fishery yields. Here, we integrated fisheries and satellite‐mapped habitat data to evaluate the effects of floodplain deforestation on fishery yields in 68 floodplain lake systems of the lower Amazon River, representing a wide range in relative amounts of woody, herbaceous and non‐vegetated land cover. We modelled relative fish yields (fish capture per unit effort [CPUE]) in the floodplain lakes as a function of the relative amounts of forest, shrub, aquatic macrophyte and bare/herbaceous habitats surrounding them. We found that forest amount was positively related (p = .0003) to multispecies CPUE. The validity of these findings was supported by rejection of plausible alternative causative mechanisms involving habitat‐related differences in amount of piscivores, fishing effort, lake area, and habitat effects on CPUE of the nine taxa dominating multispecies yields. Our results provide support to the idea that removal of floodplain forests reduces fishery yields per unit effort. Increased protection of floodplain forests is necessary to maintain the food, income and livelihood security services provided by large river–floodplain fisheries.     

杭州城市河道生态治理实践及成效

评估杭州市城市河道生态治理成效,为更好地指导城市河道生态修复工作提供借鉴。后横港、沿山河、新塘河和南大河位于杭州市中心城区,水质都处于劣V类,蓝藻水华和黑臭暴发频繁,从2014年开始,分别开展了一系列生态修复工程。测定氨氮、总磷、高锰酸盐指数、溶解氧指标判断水质改善情况,分析浮游植物、浮游动物、底栖动物判断水体生态修复程度。氨氮后横港下降超过80%,沿山河和南大河下降60%左右;总磷后横港下降接近70%,其他河道下降23%~55%;后横港、沿山河、新塘河高锰酸盐指数进一步降低,部分河道高锰酸盐指数能达到II类水水平;溶解氧浓度都明显上升,均能达到III类以上水平。南大河的浮游植物密度达到了水华暴发的水平;各条河道的原生动物和轮虫类密度都较高,但Shannon多样性指数普遍在1~2;枝角类和桡足类密度偏低;底栖动物Shannon指数均低于1,指示河道处于严重污染状态。杭州市城市河道生态治理工作的中心是:沉水植物恢复及以沉水植物恢复为基础、包含浮游动物和底栖动物等在内全水域生物多样性恢复的生态系统恢复。     

Seasonal effects of macrophyte growth on rainbow trout habitat availability and selection in a low‐gradient,groundwater‐dominated river

Rainbow trout habitat use is often described in high‐gradient, runoff‐driven, heterotrophic streams where geomorphic features and overhanging riparian vegetation provide channel complexity and cover. However, many rainbow trout populations thrive in rivers with contrasting aquatic habitat. We describe rainbow trout habitat use in a low‐gradient, groundwater‐dominated tailwater river where river flow management and macrophyte growth and senescence largely govern available trout habitat. In the summers of 2013 and 2014, available aquatic habitat (depth, velocity, macrophyte cover, substrate size) was quantified, while individual trout location was determined by radio telemetry and linked to environmental variables. Detailed habitat surveys indicate that macrophyte cover increases throughout the summer and is a strong determinant of in‐stream habitat characteristics. Paired logistic regression shows that adult rainbow trout prefer greater depths. Water depth increases with macrophyte abundance at both reach and local scales as plants restrict flow, and available trout habitat is linked to this seasonal pattern. When macrophyte abundance is high, adult trout show secondary preference for localised areas of lower macrophyte cover but otherwise show no selectivity for macrophyte cover, velocity or substrate size. Results suggest that submerged aquatic plants increased the quantity and quality of rainbow trout habitat as a source of channel complexity and cover. Macrophytes may play a similar role in other low‐gradient streams and should not be overlooked by fisheries managers considering habitat suitability.