Environmental analysis of the Norwegian fishery and aquaculture industry—A preliminary study focusing on farmed salmon

This article addresses the present status of seafood-oriented environmental methods and analyses, and pinpoints areas for further development. A recent study of the CO₂ emissions associated with the production of farmed salmon in Norway, following the life cycle from hatching to consumption, is presented. The study was initiated due to the increased focus on environmental impacts from food production among consumer organizations, retailers, and authorities. In general, several methods are being currently applied to measure environmental performance. Unfortunately, different methods provide quite different results. An additional challenge is that most of these methods were originally developed for land-based production. If assumptions about the performance of the seafood industry are established on the basis of incorrect information, consequences for both the management and the market level may not be desirable.     

近壁面柔性圆柱流致振动—拍击耦合特性试验研究

大跨度柔性悬跨海管的振动响应及管床碰撞会加剧管道的疲劳损伤,影响管道油气的安全输运。基于高速摄像非介入测试方法捕捉了近底床柔性悬跨海管的振动响应特征及管床拍击过程,对比分析了间隙比G/D及约化速度U_r对振动—拍击耦合响应的影响,辨识并提出了试验观测的管床拍击模式。研究结果表明：悬跨管的均方根振幅A_{z, rms}/D在前二阶主导模态下随约化速度U_r的升高先增大后减小;当间隙比减小时,共振区的振动频率减小,且一阶振动向二阶振动的过渡在更高的约化速度时发生,过渡时存在时间上的模态切换现象。振动平衡位置向远离壁面一侧偏移。根据悬跨管振动的主导模态与拍击特性,通过试验辨识了6种管—床拍击模式,包括一阶模态主导的小段拍击、大段拍击,一阶向二阶模态过渡时的Ⅰ、Ⅱ型拍击,以及二阶模态主导的单段拍击、双段交替拍击。     

A review of flood impact assessment approaches for underground infrastructures in urban areas: a focus on transport systems

ABSTRACT

Flooding events can produce significant disturbances in underground transport systems within urban areas and lead to economic and socioenvironmental well-known consequences, which can be worsened by variations in the occurrence of weather and climate extremes. A better comprehension of these impacts and their conditions is consequently needed. Hence, this paper presents a state-of-the-art literature review on flood impact assessment in “metro” systems, analysing their purposes and their shortcomings. This document shows the adaptation measures dealing with specific classes of pluvial flood damages, besides identifying prospective paths towards the application of suitable actions facing actual and projected hazards in metro systems worldwide.     

青岛海湾大桥对胶州湾潮汐、潮流及余环流的影响预测——Ⅱ.预测方法的探讨

旨在预测青岛海湾大桥对胶州湾潮流场产生的影响,首先对桥墩附近流场进行了数值计算,阐明了桥墩对流场影响的范围及程度,提出预测潮流变化所需的参数,尔后,对预测中所用替代方法的可行性进行了探讨。     

墩（桩）柱上流冰撞击力的研究与试验

本文简要地介绍了流冰撞击力与冰排挤压力之间的关系，给出了用于工程设计的流冰撞击力计算方法，并用模型试验对计算方法进行了验证。     

9914号台风对厦门岛东南部岸滩的环境效应

1999年14号台风于10月9日正面袭击厦门，最大风力达12级以上（47．1m/s），台风中心在厦门滞留5－6h，全市经济损失十几亿元.本文依据台风前后对厦门岛东南部海岸、沙滩的第一手调查资料以5条固定沙滩剖面多次测量比较进行综合分析。结果表明：人工护岸毁坏1／10以上、岸线后退，沙滩冲淤剧烈、沙源流失严重，海岸与沙滩环境恶化。文中还进一步探讨各种影响因素，提出今后该区域开发利用时应注意事项及防灾措施。     

Vibrating-Sliding Motion of Caisson Breakwaters Under Various Breaking Wave Impact Forces

Sliding is one of the principal failure types of caisson breakwaters and is an essential content of stability examination in caisson breakwater design. Herein, the mass-spring-dashpot model of caisson-base system is used to simulate the vi-brating-sliding motion of the caisson under various types of breaking wave impact forces, i.e., single peak impact force, double peak impact force, and shock-damping oscillation impact force. The effects of various breaking wave impacts and the sliding motion on the dynamic response behaviors of caisson breakwaters are investigated and the calculation of relevant system parameters is discussed. It is shown that the dynamic responses of the caisson are significantly different under different types of breaking wave impact forces even when the amplitudes of impact forces are equal. The amplitude of dynamic response of the caisson is lower under single peak impact excitation than that under double peak impact or shock-damping oscillation impact excitation. Though the disp     

规则波作用下二维水平板冲击压力概率分析

通过模型试验的方式研究了波浪对二维水平板冲击压力峰值的概率分布。首先,统计分析了水平板底部各测点的压力峰值,发现密闭水平板底部各位置处的压力峰值分布与三参数威布尔分布吻合较好;然后,从统计学与概率论的角度进一步探讨了水平板底部各位置处压力峰值分布函数的参数与测量样本统计特征值之间的关系;最后,通过不同入射波浪工况的对比,分析了威布尔分布各参数与测点相对位置、入射波相对波高以及入射波相对波长之间的关系及其所代表的物理意义。统计分析显示:威布尔分布的相对位置参数(θ/-P)从水平板前端到后端呈现先增大后减小的趋势,在水平板中段较恒定(约为0.6);相对尺度参数(λ/-P),在水平板中段偏小,两端偏大;形状参数(κ)在相对波高较大时,在水平板的中段偏大,并且相对波长大于1.3时,κ在水平板的中部均值随相对波长的增大而减小,相对波长为2时,该值接近于1。     

Modelling analysis of the sensitivity of shoreline change to a wave farm

Change of shoreline wave climate caused by the installation of a wave farm is assessed using the SWAN wave model. The 30 MW-rated wave farm is called the ‘Wave Hub’ and will be located 20 km off the north coast of Cornwall, UK. Changes in significant wave height and mean wave period due to the presence of the Wave Hub are presented. The results suggest that the shoreline wave climate will be affected, although the magnitude of effects decreases linearly as wave energy transmitted increases. At probable wave energy transmission levels, the predicted change in shoreline wave climate is small.     

烟台市辛安河污水处理厂排污混合区范围论证

烟台市辛安河污水处理厂二期工程建成后污水全部实行深海排放,该工程海域使用论证报告已拟划定排污混合区范围。根据污水排放量和主要污染物类型,结合纳污海域现状水质调查,通过建立二维污染物输移扩散模型,对出水中主要污染物COD、氨氮(NH_3—N)、总磷(TP)进行影响预测,以污染物的影响范围为主要依据,对拟划定的排污混合区范围作了论证,结果显示,拟划定的混合区面积偏大。且相对排污口位置偏北,不能正确反映污染物的影响范围。文中提出了较为合理的混合区范围。