Power plant siting on Wisconsin's coasts: A case study of a displaceable use

Abstract

The issue of whether power plants should be located on Wisconsin's Lake Michigan shore or inland is addressed in this article. It is quite likely that sites for several large power plants will be needed before the year 2000. Available evidence on the comparative costs of condenser cooling indicates that there may or may not be substantial economies from locating these plants at lakeshore sites depending on site characteristics, fuel costs, and other variables. Environmental impacts of coastal and inland siting are surveyed and also appear to be highly site‐specific. Important issues arise with respect to the intense competition for coastal land and the aquatic impacts at both coastal and inland sites. A third alternative, that of utilizing sites that are in the coastal zone but set back from the water's edge, has some promising aspects, but data on costs are scarce and inconclusive. Conclusions center on the importance of not ruling out either coastal or inland locations in future efforts to identify suitable power plant sites, the need to review current water‐quality measures, and the need for further research on institutions to facilitate sound siting decisions.     

长江口南支河势演变模式分析

20世纪70年代以来,长江口南支河势呈现出良好的规律性变化,形成了自身相对稳定的演变模式。这种演变模式的构成既与南支边界条件的改变密切相关,也受上游下泄水沙的影响。以历年地形和水沙资料为基础,详细分析南支沙体与沙体之间、沙体与主槽之间的演变规律及影响关系,阐述上游水沙变化和周边工程对南支河势演变进程的影响,并对南支河势的演变模式作探讨性概括。     

长江口航道服务系统仿真与优化

针对长江口南槽航道加深工程中不同方案条件下经济效益评价问题,采用双时钟机制设计船舶预排队优化模型并构建长江口船舶交通仿真系统,基于长江口航道特点、船舶尺度、潮汐和通航规则等影响因素对系统进行比较仿真,得出南槽航道加深工程不同方案经济效益评价所需的船舶等待时间、航道利用率等指标值,为本工程实施的方案选择提供了合理的建议。     

深圳至中山跨江通道矾石水道远期预留航道等级论证

探讨了珠江口矾石水道在远期深圳至中山跨江通道(下称"深中通道")投入使用时所需预留的通航等级,以避免深中通道影响珠江口两岸各港船舶通航的安全、顺畅。综合考虑珠江口现状通航条件和远期港口规划,初步提出矾石水道预留10万吨级通航等级的必要性,并利用数值模拟、综合物探等手段,重点从矾石水道的深槽稳定性、通航水流条件、航道可挖性和航道可维护性进行分析论证,同时对比国内典型规模化港口,阐明港口吞吐量规模对航道资源的要求,提出矾石水道预留航道等级应考虑的因素,最终认为矾石水道预留航道等级为10万吨级是必要的、可行的。     

枕箱、龙穴南水道航道疏浚工程对蕉门出海水域影响的计算分析*

蕉门出海水道分为枕箱水道和龙穴南水道,其航道整治工程以疏浚为主。采用河床演变分析和二维嵌套潮流悬沙数学模型,研究了枕箱、龙穴南水道航道疏浚工程对蕉门出海水域的影响。研究表明:1)蕉门出海水道一主(枕箱水道)一支(龙穴南水道)的格局基本稳定,河床演变相对稳定,枕箱水道分流比呈减小趋势;2)疏浚工程实施后,对龙穴南水道和枕箱水道分流比、流场、含沙量场和冲淤变化影响较小,引起的变化仅在航道疏浚段及其边滩附近;3)由于疏浚工程量较小,对蕉门出海水域的水沙动力条件没有明显的影响。     

长江口南北港分汊口河段护滩限流工程动态管理

在长江口深水航道南北港分汊口河段新浏河沙护滩及南沙头通道潜堤工程的设计、建设及维护过程中,全面、科学地实行动态管理,保证了工程顺利建成,取得了预期整治效果。是在长江河口整治中实施动态管理的一次成功实践,积累了丰富的工程管理经验。     

鸭绿江口4万吨级双浮筒系泊系统设计与计算

为了在鸭绿江口设计一双浮筒系泊系统,用于4万吨级散货船的载驳作业,根据该海域的水文气象条件和船舶的有关资料及国家的有关规范,对双浮筒系泊系统所受风作用力、流作用、波浪作用力和合外力进行计算,依据计算结果对双浮筒系泊系统进行设计,确定系泊浮筒型号、锚链尺寸和长度及沉锤大小和掩埋深度,实际施工情况依照该设计方案效果良好,证明该计算和设计方法有效可行。     

上海崇明越江通道工程环境地质问题及其防治

上海崇明越江通道工程是长江河口地区重要的国家基础性建设项目,所在区域不良地质条件易给工程施工带来不利影响。文章阐述软土变形、水土突涌、水下砂体运移、浅层天然气、岸带冲淤、砂土液化、地面沉降等环境地质问题及其潜在的工程危害,提出相应的防治对策与技术措施。     

内伶仃洋水域洪枯季余流及净潮通量时空变化特征

基于内伶仃洋水域4座观测站洪、枯季半月的连续观测资料,分析了该水域余流和净通量时空变化特征,探讨主要动力因子的作用规律。研究显示,内伶仃洋水域半月水深平均余流流速洪季不超过10 cm/s,枯季不超过5 cm/s,洪、枯季总体指向外海侧方向。湾顶水域水沙通量洪、枯季均呈自西向东净输运,且与径流动力呈强正相关。主槽水域接纳东、西两侧浅滩水沙后始终朝西南外海输送。西滩水域洪季水沙朝外海方向净输出,枯季变为朝西北侧上游方向净输送,洪、枯季均与径流动力呈强正相关;淇澳岛北侧西滩水域洪、枯季水沙通量均处于净输入状态,导致该水域不断淤浅。采用多元线性回归法对主槽水域表层余流与主要动力因子进行拟合分析,显示潮汐动力始终驱使表层水沙朝上游方向净输运,径流动力作用方向洪季指向外海、枯季指向上游,海面风则驱使表层水沙与自身方向保持一致;拟合公式中的常数反应了地转科氏力等综合作用下的内伶仃洋水域表层水沙西南向输运规律,且枯季较洪季更为明显。     

Lessons Learned from Lake Shiwha Project

The Lake Shiwha Project was planned in the late of 1980s about 10 years before establishing ICZM policy and wetland conservation policy in Korea. The project was to build a dike of 12.7 kilometers in the mouth of a estuary, thereby to keep freshwater instead of brackish in the lake and to create land of 110 square kilometers for agriculture and industrial complex by draining out of associated wetland. However the Korean government abandoned keeping freshwater in the lake as soon as completing the dike because of not being able to control of serious pollution in the lake. This article analyzes the characteristics of the project such as bias of feasibility, degree of transformation and time period of loss of goal that led into environment disaster and extracts some implications for lessons.