The California Coastal Act and Ports: The Unintended Environmental Justice Implications of Preserving California's Coastline

Consistent with the policies set forth in the Coastal Zone Management Act, the California Coastal Act seeks to balance the utilization and conservation of coastal resources, taking into account the social and economic needs of the citizens of California. One way the statute pursues this balance is through its provisions for ports. These provisions have functioned as a type of smart growth planning for ports, encouraging densification of existing port districts and possibly averting maritime commercial and industrial sprawl along the California coast. One unintended consequence of the encouraged consolidation of port activities, when combined with the rapid growth in international trade over the last four decades, has been disproportionally large environmental and health impacts on low-income and minority communities surrounding ports. This article examines how the Port of Long Beach's conformance with the California Coastal Act has resulted in ongoing environmental justice concerns. It discusses approaches employed by the Port of Long Beach to reduce environmental justice concerns resulting from significant and unavoidable environmental impacts and offers suggestions for how to address this issue.     

Managing Beach Amenities to Reduce Exposure to Coastal Hazards: Storm Water Pollution

Despite posted warnings and educational campaigns warning about the health risks associated with storm water pollution, swimmers continue to swim in coastal areas polluted by storm water runoff. This study uses a simple spatial model of beach visitation to show how beach amenities and storm drains influence the way in which beach goers choose to locate themselves at beaches in Santa Monica Bay, California. The estimated models indicate that passive means of preventing exposure to marine pollution (e.g., posted signs) could be made significantly more effective if combined with the active management of other beach amenities. Similar methods also could be used to reduce risks to swimmers from other hazards including riptides and boat traffic.     

北盘江坝油滩河段整治流量与整治线宽度的研究

总结以往航道整治工作经验,结合整治河段的实际情况,对北盘江坝油滩河段重要整治参数———整治流量与整治线宽度进行了深入细致的分析研究,得出了较为合理的结果。     

Comparison of Beach Nourishment along the U.S. Atlantic,Great Lakes,Gulf of Mexico,and New England Shorelines

The U.S. national beach nourishment experience is summarized for the East Coast barrier islands, the Gulf of Mexico, New England, and the Great Lakes. A total of 1,305 nourishment episodes on 382 beaches are recorded at a total estimated cost of approximately $1.4 billion ($2.5 billion in 1996 dollars). In terms of both volume and costs, nourishment has been the most extensive by far on the East Coast barrier islands. Depending on the region, between 65% and 85% of all nourishment projects have a federal funding component. Annual expenditures and sand volumes for beach nourishment are increasing, especially on East Coast barriers. At present, total annual national beach nourishment costs (excluding the Pacific Coast) are on the order of $100 million per year. The cost per cubic yard of nourishment sand as expressed in 1996 dollars has remained more or less constant over time. Additionally, the volumes of sand needed for subsequent nourishment episodes on individual beaches do not decrease, despite contrary assumptions in the shoreface-profile-ofequilibrium concept that subsequent nourishment volumes should diminish. In light of the historical experience of beach nourishment identified in this study, individual state and local coastal communities should reevaluate their plans for future beach nourishment programs. The complete listing of all the data on nourished beaches from this survey is available at www.geo.duke.edu/Research/psds/psds.htm     

The Potential of a Legislative Approach to Managing Beach Use: The Case of Beach Bylaws in the Republic of Ireland

This article examines the use of inland mined sand and offshore dredged sand for beach nourishment projects in North Carolina, focusing on the question of whether inland mined sand is economically preferential for hot‐spot erosion control. Excavation, processing, and transport costs are presented, and cost efficiencies of hypothetical beach nourishment projects are compared. Cost analyses indicate that inland mined sand is economical for small projects (10,000–50,000 cubic yards), given that a clean sand source can be located within 15 miles of the nourishment site. The two factors primarily influencing per cubic yard costs of inland sand are overland transportation expenses and processing costs. The use of dredged offshore sand is less expensive for large projects (> 100,000 cubic yards) due to the economies of scale affecting dredge mobilization. Large beach nourishment projects in North Carolina will most likely continue to utilize offshore dredged sand.     

一种滩涂作业车辆气动换挡操纵机构

本文针对滩涂作业车辆行驶阻力大和换挡操纵距离远造成的换挡困难现象,设计了一种可远距离操控的气动换挡操纵机构。根据实测选档及挂档作用力,设计了一种由通用气缸和电磁阀组成的远距离换挡操纵机构,经实车试验后解决了上述难题。     

辽宁滨海大道锦州海滩段软土路基处理设计

根据辽宁滨海大道锦州海滩段路基所处的特殊的环境及工程地质特征,分析了控制本项目的关键岩土问题及施工难点,并介绍了具体路基处理设计。     

Coastal Erosion and Its Social and Environmental Aspects in Tanzania: A Case Study in Illegal Sand Mining

Coastal erosion is one of the major coastal problems currently facing Tanzania. Several factors, including sea level rise, geology, and rapid coastal population growth accompanied by rapid increase of human activities that interfere with natural processes, have been linked to the problem. One of the human activities that have been well linked to the problem of coastal erosion is illegal sand mining along beaches, coastal streams/rivers, and other restricted areas. This causes localized accelerated/ severe coastal erosion and enormous environmental degradation and threat to coastal properties. Illegal sand mining is presently a big industry in Tanzania, employing many youths, and has become a social, economical, and environmental problem. Thus, it is a sensitive issue. The problem of illegal sand mining in Tanzania is revisited, and possible measures to control it are proposed. Measures that can help to reduce/eliminate illegal sand mining are: governments to address effectively the problem of unemployment and poverty in the society by formulation of effective policies, including the total liberalization of the labor market and reduction of the tax burden and regulations on potential employers; identifying alternative sources of sand that are environmentally safe to mine, of good quality, and easily accessible; launching well-focused mass education on the problem of coastal erosion; encouraging formation of legally registered associations of sand-miners that will work closely with relevant authorities to curb illegal sand mining; and strengthening of governance and improving research funding in the country.     

南汇东滩促淤工程南区设计波浪要素研究

针对南汇东滩促淤工程所处的位置,选用基于波能平衡方程和波作用守恒方程的近岸风浪谱模型建立波浪传播计算数值模型,对非线性效应影响条件下的波浪要素进行计算研究。研究结果表明,波浪在远距离的传播过程中,受到沿程的风的影响,组成波之间能量交换转移和耗散等非线性效应的影响不可忽略,在南汇东滩海域采用近岸风浪谱数值模型对波浪的传播变形计算较为合适。     

长江上游铜鼓滩治理措施研究

铜鼓滩处于两反向河湾的过渡段,枯水期上口水深浅,不满足尺度要求,中段航槽落湾,弯曲半径小,下口流速大,流态乱,上下水船舶航行危险。在有关模型试验成果的基础上,通过研究分析滩段的演变规律及碍航机理,对弯道浅险滩的整治方案和整治建筑物结构等治理措施进行了探讨,对治理效果进行了评价,这对山区河流类似滩段的治理提供了一定借鉴。