Hydraulic performance and wave loadings of perforated/slotted coastal structures: A review

This paper reviews recent progress in the study of perforated/slotted breakwaters, with an emphasis on two main groups of such breakwaters: (1) perforated/slotted breakwaters with impermeable back walls, and (2) perforated/slotted breakwaters without a back-wall. The methods commonly used to simulate the interactions between such structures and various linear/nonlinear waves are summarized. The transmission and reflection characteristics of perforated/slotted breakwaters in these two groups are reviewed extensively. Several methods for calculating wave forces on perforated caissons are also reviewed. Some recent works published in Chinese journals, which are generally not well-known to non-Chinese researchers, are reviewed with a hope that these works can be beneficial to other researchers working in this area.     

美国州际政治地理与奥巴马的白人选票

最近30年,许多关于美国政治地理的讨论主要包含4个州际种族和民族理论：黑人威胁论、州际文化差异论、种族多样性：哩论和社会资本论。本文将同时应用这4种理论来解释美国历史上第一位非裔总统巴拉克奥巴马的当选原因。研究表明：种族构成复杂程度和白人选举黑人候选人的意愿之间存在负相关性,而美国的多元文化却正面影响白人选民对黑人的支持。具体而言,黑人密度不断增加与种族之间的紧张度的提高都负面影响白人选举奥巴马的意愿。然而,白人投票者的社会资本积累和“道德政府”的州际政治文化的存在则有助于大选中自人对奥巴马的支持。     

滨海湿地生态补偿机制建设初探

初步探讨了我国滨海湿地生态补偿机制框架,确定了生态补偿的范围为生态地位重要、生态环境脆弱的滨海湿地,补偿主体为政府和湿地开发利用者,补偿客体为滨海湿地管理者和保护者;提出了补偿标准测算应注意的问题和可供选择的方法;从资金补偿和项目补偿两个方面探索了补偿方式和途径;并提出了完善滨海湿地监测和管理系统、明晰滨海湿地产权、推进生态补偿市场化运作、完善生态产业等生态补偿实施对策措施。     

广州南部滨海地区工程地质问题及对策

松软土地基、活动断裂、砂土液化和海水入侵是滨海城市普遍存在的主要工程地质问题。对广州南部地区这四种问题进行深入地研究,绘制广州南部工程地质专题分区图。对滨海城市建设可能引发的工程地质问题进行评价和分析,并提出相应对策。     

海岸带土地利用格局演化及多情景开发模拟¬——以宁波市为例

海岸带土地在高强度开发下变化显著,明确其演化规律和驱动因子,为优化土地利用结构和合理利用海岸带资源提供重要依据。基于1990－2020年7期土地利用数据,利用土地利用强度指数、地理探测器模型等方法,分析宁波市海岸带土地利用格局演变特征及驱动因子;同时利用CA-Markov模型对2025年和2030年宁波市海岸带土地利用格局进行模拟。结果表明：（1）宁波市海岸带土地利用类型主要为林地和耕地,土地利用格局演化明显,其中耕地面积不断减少,林地、草地、水域和未利用地面积发生小幅度动荡,建设用地面积快速增长。（2）宁波市海岸带土地利用强度不断增加,研究区北部增长趋势明显,而南部增长速度缓慢。（3）地形和坡度是影响宁波市海岸带土地利用变化的主要自然因素,但影响程度不断减弱;GDP密度和人口密度是主要社会经济影响因素,影响强度逐渐增强;因子间交互作用类型主要为双因子增强和非线性增强,社会经济因子与自然因素中的海拔和坡度交互作用最为强烈。（4）未来宁波市海岸带土地利用变化剧烈区域将集中于杭州湾南岸、象山县东北部和宁海县南部,生态保护情景能最大程度保持土地利用结构稳定,有效缓解人地矛盾。     

Nutrient distribution and fluxes from three Mediterranean coastal rivers (NE Algeria) under large damming

Nutrient distribution and fluxes into and from dams and into coastal waters from three rivers (NE Algeria) were assessed during a one-year period in three stations for each river: at the entrance and the exit of dam and at the outlet. The main characteristics of the rivers were the high levels of NH₄ and PO₄, even in dam entrances, contrarily to SiO₄ levels that are still low upstream the dams. From the inorganic nutrient incoming fluxes, the dams trapped annually 42 to 93%, depending on the nutrient, but released in great levels dissolved organic forms at their exits. At catchment scale, dissolved nitrogen loadings reach 338 kg/km²/yr, in which the organic fraction forms up to 34%; while those of dissolved phosphorus reach 172 kg/km²/yr, with a great organic fraction. The Si:N ratios decreased while N:P ratios increased at river outlets, indicating large inputs of N over P in the lower catchments.     

计算机支持下的协同设计技术研究

介绍了计算机支持的协同工作的概念,分析了协同设计中存在的冲突和解决方案,阐述了协同设计研究中存在的问题,为进一步开展研究工作奠定了基础.     

Feedback switching and the evolution of U.S. coastal management

Feedbacks occur when advocates engage to clarify the implementation of a policy innovation such as the requirement that federal activities be consistent with objectives of state coastal management plans. Discrete policy feedbacks include advocacy, litigation, appeals of decisions as well as other activities inserted into policy implementation by interests or government agencies acting in their behalf. Feedback analysis is applied to the time after the passage of the 1972 U.S. Coastal Zone Management Act. Conflicts after passage of the law resulted in a negative feedback in the form of a Supreme Court decision in 1984 and a subsequent positive feedback through the 1990 revision of the law effectively reversing the Court decision. New insights documented here suggest that feedback switching, wherein old disputes are moved to new arenas, provides the greatest opportunity for overcoming negative feedbacks that could diminish or eliminate the policy innovation. Furthermore observing feedbacks through time and across multiple policy spaces as demonstrated here provides a robust interpretation of policy evolution from a new perspective. This analysis demonstrates how feedbacks convert a voluntary state program into one with authority over certain federal actions. These findings will be important for other areas of coastal policy and, more broadly, policy evolution in general.     

The influence of environmental variability of a coastal lagoon ecosystem on genetic diversity and structure of white seabream [Diplodus sargus (Linnaeus 1758)] populations

As coastal lagoons serve as nursery areas for some marine and estuarine fish, selective pressures of these brackish or hypersaline lagoons may influence the genetic structure of species and populations. We examined spatial and temporal genetic patterns at eight microsatellite loci in white seabream [Diplodus sargus (Linnaeus 1758)] recruits from the Mar Menor (Southeast Spain) and compared these loci with those in coastal populations from the open sea, observing a high degree of genetic diversity and spatio‐temporal genetic stability. However, the results suggest the presence of subpopulations or genetic substructures in the Mar Menor D. sargus population that could be interpreted as a homogeneous mixture of individuals from three differentiated subpopulations in the Mediterranean and evidence of the Wahlund effect. It also suggests that D. sargus adults return to their original spawning habitat, thus conserving the genetic differences among the respective populations over time. Overall, this study demonstrates the importance of the Mar Menor coastal lagoon as a nursery area for the conservation of genetic diversity of D. sargus populations.     

Destabilizing the identity–territory nexus: Rights-based discourse in Sri Lanka’s new political geography

This paper describes the changing discourses of territory in Sri Lanka and their utility in conflict relations. The primordial homeland has been at the center of Sri Lanka’s armed struggle, in which both Sinhalese and Tamil nationalisms have used claims of ancient and ethnically determined territories to justify their right to self-determination, territorial sovereignty, and armed struggle. This identity–territory nexus based on historical argument has been destabilized in Sri Lanka, however. Scholarly findings suggest that historical linkages between ethnicity and territory in Sri Lanka are highly problematic and are no longer effectual means for adjudicating territorial desires in Sri Lanka and producing stable homelands. I argue that rights-based territorial discourses have emerged to enhance the old historical justifications for territorial authority. New narratives based upon fulfilling or denying human rights have been put to work linking authority to territory based upon moral fitness and unfitness, political legitimacy and illegitimacy, and ultimately, upon which political actor deserves to rule the territorially bound population under its control. The first part of the paper examines historical narratives linking national homelands to identity as well as scholarly work that deconstructs this linkage. In part two, external sovereignty and political legitimacy are discussed as the starting point for understanding how rights-based discourses justify territorial claims. In part three, accusations related to human rights violations are described as an important vehicle for shaming political adversaries, undermining their legitimacy, and making and unmaking territorial claims in Sri Lanka.