Effect of seaweed proliferation on benthic habitat quality assessed by Sediment Profile Imaging

Changes in sediment quality, with special reference to benthic habitat conditions resulting from macroalgae overgrowth, were studied in the Venice Lagoon, Italy. Data were collected biweekly in spring and summer from 1993 to 1998 and from 2001 to 2002, as part of the macroalgae growth control strategies managed by the Venice Water Authority-Consorzio Venezia Nuova. Benthic habitat conditions were studied by means of Sediment Profile Imaging, which allowed the collection of several variables: aRPD (apparent redox potential discontinuity), prism penetration depth, presence of anoxia on the surface of the sediment, presence of reduced gas bubbles, stage of benthic colonization. All these variables led to the calculation of an environmental index (Organism–Sediment Index, OSI), which was then related to physical variables and macroalgae abundance. Until 1996, the overall benthic habitat of the Venice Lagoon showed almost stressed conditions; from 1997, the seaweed biomass rapidly declined and the OSI increased significantly. The OSI seemed to be affected by seaweed biomass, sediment compactness and water depth. Macroalgae biomass greater than 4.5 kg/m² led to the complete disappearance of stage III of benthic colonization; values as low as 0.70 kg m² already had a severe impact on recolonization. SPI attributes indicated the main mechanisms that could have contributed to the benthic quality: seaweed proliferation is often followed by rapid decay of macroalgae biomass, especially when present in large amounts. The decrease in seaweed biomass often results in oxygen depletion in the water column and thus in the sediment, preventing complete benthic colonization. This research confirms the importance of in situ rapid reconnaissance surveys to assess the impact of eutrophication on the benthic habitat.     

拉日铁路对西藏“一江两河”地区黑颈鹤栖息地影响评价研究

“一江两河”河谷区作为黑颈鹤主要越冬栖息地之一,境内铁路建设运营必然会对黑颈鹤栖息环境造成负面影响。而目前针对动物影响评价多采用线位关系法与种群密度法在该区不具科学性与操作性,严重降低了铁路建设对黑颈鹤影响评价结论的可靠性与科学性。本文在近两年的野外观测试验与资料总结的基础上,从铁路工程占地、列车灯光、噪声、运营阻隔等方面结合黑颈鹤越冬生态行为特征,系统论证了铁路工程对黑颈鹤越冬期的影响强度,并提出针对性的治理措施,实现了经济效益和生态效益的双赢。     

城市地铁线与常规公交线路接驳问题初探

通过分析常规地面公交起讫点与轨道交通吸引半径的关系,结合青岛地铁1号线黄岛段的具体情况,研究城市地铁线与常规公交线路接驳问题.对已有常规地面公交线网和新增接驳公交线网进行调整和优化,初步实现了城市轨道交通与常规公交接驳的两方面功能:一方面多模式分层次的公共交通结构满足不同的出行需求,增强公共交通的吸引力,提高公共交通在出行方式中的分担比例;另一方面,常规公交为城市轨道交通集散客流,降低两者之间不合理的竞争,达到公共交通系统内部双赢,为乘客提供高效、便捷的出行服务.     

长江上游洛碛河段航道整治工程对鱼类生境影响研究*

近年来,随航运经济飞速发展,长江流域内航道整治工程频繁,虽然航道整治工程能改善水流条件,但也对鱼类栖息地有一定影响。为探究不同航道整治工程对鱼类生境影响,以长江上游洛碛河段为例,采用数值模拟方法,从生态与水力学角度对比分析洛碛段航道整治工程前后四大家鱼的鱼类生境适宜性变化情况。结果表明：航道整治工程后,鱼类栖息地非常适宜区间的面积占比最多增长了1.21%,不适宜区间的面积占比最多降低了1.85%,并且上洛碛副槽随水位和流量增加,会产生适宜生存的栖息地环境。     

A Participatory Approach to Marine Habitat Mapping in the Grenadine Islands

Increasing interest in implementing an ecosystem-based management approach has made stakeholder involvement vital and has highlighted the need for an effective participatory framework. In this study we used a participatory geographic information systems (PGIS) framework to collaboratively map the marine resources of the transboundary Grenadine Islands with a broad range of stakeholders from the two sovereign nations. We found the application of PGIS allowed the collective resolution of an appropriate mapping scale and a locally relevant habitat classification scheme that would not only serve the needs of resource managers, but could also be understood by resource users. Furthermore, multi-level stakeholder involvement in the mapping process captured resource use profiles and other fishing-related attributes, gave credibility to local knowledge and ownership of information, and was instrumental in building capacity to access and use the produced information. Lessons learned included the importance of investing considerable time early in the participatory process, which was later rewarded by stakeholder buy-in and led to financial and in-kind support. Furthermore, hosting the information in multiple formats on a project website has resulted in easy access and use by a wide range of stakeholders over a cross-country scale. We believe our experiences will be valuable to other practitioners considering using PGIS, particularly for those working in similar resource-limited, developing nation contexts.     

公路两栖类动物通道设置方法研究

鉴于目前关于我国公路建设中两栖类动物通道设置方法还缺少系统性研究,基于国内外成功经验,结合我国国情,初步提出了公路两栖类动物通道的设置方法,包括位置确定、诱导生境（包括微型水塘群和迁徙走廊） 设置、迁徙走廊保护设施（隔离栅、易进出的构造物和标志牌）设置、效果评价等。以交通运输部典型绿色循环低碳示范路——鹤大高速公路穿越靖宇国家级自然保护区段为依托工程,应用上述方法设置了6 处两栖类动物通道,指出了未来要继续深化研究通道的关键参数和设计要求等,以促进我国道路生态学的发展。     

城市地铁线与常规公交线路接驳问题初探 ——以青岛地铁1号线黄岛段为例

通过分析常规地面公交起讫点与轨道交通吸引半径的关系,结合青岛地铁1号线黄岛段的具体情况,研究城市地铁线与常规公交线路接驳问题。对已有常规地面公交线网和新增接驳公交线网进行调整和优化,初步实现了城市轨道交通与常规公交接驳的两方面功能：一方面多模式分层次的公共交通结构满足不同的出行需求,增强公共交通的吸引力,提高公共交通在出行方式中的分担比例;另一方面,常规公交为城市轨道交通集散客流,降低两者之间不合理的竞争,达到公共交通系统内部双赢,为乘客提供高效、便捷的出行流程。     

Numerical evaluation method of lightning rod protection probability北大核心CSCD

［Objectives］Aiming at the current situation in which it is difficult to efficiently evaluate protection probability through traditional lightning rod evaluation methods, an efficient numerical evaluation algorithm is developed on the basis of an electrogeometric model (EGM) and attractive volume to realize the efficient calculation of lightning protection probability at any point in space.［Methods］This method first determines the attractive volume boundary of the lightning rod and protection object according to the interception process of the upward and downward leaders. The collection surface and exposure arc of the lightning stroke distance are then calculated, enabling the attractive risk and interception effect of the lightning rod to be quantified. Finally, the attraction and interception characteristics of the lightning rod are integrated to establish a numerical evaluation model of protection probability. To verify the accuracy of this method, the general rule of lightning rod protection probability is analyzed and the results compared with the existing analysis method.［Result］The evaluation results of this method show good agreement with those of classical leader progression model (LPM) theory.［Conclusions］ The method proposed herein has a high degree of quantification and can realize the efficient calculation of lightning protection probability at any point in space, which can provide useful references for lightning protection design work. © 2023 Authors. All rights reserved.     

基于生态行为与栖息地选型的珍稀野生动物影响及保护研究

对四种珍稀涉禽类野生动物对宝中线黄河铁路特大桥影响响应机制进行研究。结果表明,四种珍稀野生动物对铁路运营已适应,并在河心滩、河岸滩范围内形成了两种截然不同的选择偏好性区域,野生动物对铁路桥的趋避距离在100—120m以上,通过改变影响区滩地地表植被群落结构特征以及对栖息地进行异地重建的方式可以降低和消除铁路运营对野生动物的影响。在此基础上本文认为,在铁路工程野生动物影响评价过程中,应首先根据野生动物生态行为对受影响动物群落进行筛分,选出敏感控制因子作为评价重点对象,同时根据区域自然环境、工程内容等方面进行分析论证影响水平,最后以此为基点提出针对性的保护措施。