Developing a Sustainable Community-Based Aquaculture Plan for the Lagoon of CuyutlÀn through a Public Awareness and Involvement Process

This study presents evidence from the Cuyutlàn lagoon, which demonstrates that aquaculture can be socially acceptable, economically viable and environmentally friendly when consideration is first taken of the local circumstances and environment. This evidence was obtained through a user survey, which asked key questions of the local fishing community. These questions aimed to determine the desires and needs of the local community in the context of the local environment. The results from this survey of 56% of the fishing community were presented. The wishes of the fishing community are discussed and a compromise suggested for a sustainable aquaculture for the Cuyutlàn lagoon.     

The Demise of a Tropical Coastal Lagoon as Breeding Habitat for Ground-Nesting Waterbirds: Unintended,but Anticipated Consequences of Development

Laguna Cuyutlán (Colima, Mexico), an Important Bird Area, used to provide breeding habitat for ground-nesting waterbirds. During 2014 and 2015, nesting efforts of laughing gull, black skimmer, and royal, gull-billed and Forster's terns failed almost completely due to inundation, while least terns and snowy plovers fared the same during 2014. No anomalies in rainfall, tidal level, or coseismic subsidence explained such failure. Rather, the inundations were due to the enlarging of Canal Tepalcates that connects the lagoon with the sea, which was widened from 100 to 300 m and dredged to 17-m deep. Before this, the hydrodynamics were regulated by evaporation and runoff. Now, increased seawater volumes dominate the basin's hydrodynamics. The failure of Laguna Cuyutlán as a breeding habitat for these birds is an important threat for these species, as this lagoon held one of the < 20 colonies known for several of these species along the western coast of North and Central America. Documenting this demise of Laguna Cuyutlán for ground-nesting waterbirds transcends the regional scale as it emphasizes the little consideration still given to biodiversity vs. economic development, and is a warning for coastal projects in other developing areas of the world.     

Temporal variations of water flow between the Venetian lagoon and the open sea

Long-term measurements of the water flow at three Venice Lagoon inlets with the bottom-mounted ADCPs show that the main part of the variance (>90%) is associated with the tidal variability. Semi-diurnal constituents (mainly M2 and S2) are responsible for about 80% of the flow variance. Phase-lag between the axial current and sea-level is on the order of 2 h for M2 and 4 h for the K1, the maximum inflow leading the sea-level maximum. Phase-difference of tidal flows between inlets shows that Chioggia leads both Malamocco and Lido, suggesting that tidal signal progresses northward, thus in the opposite direction of both the semi-diurnal and diurnal tidal signals in the open Adriatic currents. The sea-level slope between the open sea and the lagoon interior controls the inlet flow, which is due to the time lag being constant for all tidal constituents. It was shown that tidal oscillations at Punta Salute (lagoon interior) lag those in Lido by about 45 min. The pressure gradient due to the sea-level slope generates the flow acceleration. Only for large current speeds (>0.5 m/s), the bottom friction term becomes equally important as the local acceleration and the horizontal pressure gradient terms. Wind effects manifest as a remote forcing through Adriatic seiches at semi-diurnal and diurnal scales, and as a local forcing at very long time scales on the order of a month. This latter mechanism is limited to a winter period (November–January). Seiches are present over the entire year, being however, more energetic and frequent during autumn and winter.     

可渗透岛礁环境下的波浪运动研究

文章应用边界单元法,依据波浪绕射理论研究了潜淹没岛礁上的波浪运动问题。研究中分析了岛礁的渗透性、排布的数量、环礁泻湖的深度等因素对于岛礁消波作用的影响,获得了不同岛礁环境下波浪的透射系数、反射系数。研究发现,可渗透岛礁的消波效果比不可渗透岛礁差,且孔隙率越大,岛礁对于波浪的消波效果越小;单个岛礁对长波有明显的消波作用,而对中短波几乎没有影响;但随着岛礁排布数量的增加,岛礁群对于中波的消波效果增加;环礁的消波效果受到泻湖深度的影响,在一定范围内,泻湖的深度越大,环礁对于中短波的消波效果越好,但当泻湖深度达到一定数值后,继续增大深度,消波效果基本没有提高。     

Developing the Vision: Managing the Coastal Zone of Magnesia through Information and Consent

The ICZM project of Magnesia in Greece, funded under the EU LIFE Programme, has provided a first chance for experimentation on procedures for integrated coastal planning at the local level. In a country where the mechanisms and the procedures of planning have failed repetitively and been replaced by market mechanisms, the main objective was to set the appropriate conditions for sustainable coastal management. A first intervention was the creation of a strong database, a Geographical Information System (GIS), which aimed at the improvement of decision making. The second intervention was the experimentation with consultation and participation pro cedures. At the end of this project we have the information tools that are necessary for the management of Magnesia's coastal zone and are wiser about consultation and participation procedures.     

A finite element model for the Venice Lagoon. Development, set up, calibration and validation

The development, calibration and validation of a two-dimensional finite element model for the Venice Lagoon is described. The model uses a staggered grid for the spatial integration of the water levels and velocities. A semi-implicit numerical time stepping scheme is implemented, which guarantees unconditional stability for the gravity wave propagation. Because of the shallow depths in the lagoon, the model deals also with areas where flooding and drying occur.A first calibration of the model has been performed against harmonic constants of 12 tide gauges located in the lagoon. After this calibration, model output shows a good agreement with a set of water level data referring to a period of calm winds and to another data set of water level data measured in 38 stations during a period of strong winds.Meteorological data and river discharges are used to set up a 1-year long simulation that models the salinity and temperature fields. The temperature time evolution is well simulated. Comparison of model output to salinity data is not straightforward, since input data for the main rivers that discharge freshwater into the lagoon is not available for the year of reference. However, yearly averages of observed values of salinity are in a reasonable agreement with results of a climatological simulation.The presented model shows good propagation of the tidal wave and stability characteristics. It is the first step for a comprehensive model of the Venice Lagoon that deals not only with hydrodynamic variables, but also with sediment transport and ecological processes.     

Carbon and nutrient dynamics in a hypertrophic lagoon in southwestern Taiwan

Dissolved and particulate phases of carbon (DIC, DOC, POC) and nutrients (DIN, DIP, DSi, DON, DOP, PN) were investigated bimonthly from August 1999 to August 2000 to study biogeochemical dynamics of carbon and nutrients in Tapong Bay, a small semi-enclosed and hypertrophic lagoon in southwestern Taiwan. The lagoon has only a tidal inlet for exchanging water between Tapong Bay and Taiwan Strait, which may result in low water exchange rates and various oxygen-deficient conditions in bottom water of the inner bay during warm seasons. The water exchange time of Tapong Bay ranges from 7 days (summer) to 13 days (winter) with a mean of 10 days. Nutrient dynamics were largely ascribed to allochthonous inputs, biological and exported removals in the lagoon. Diffusion fluxes from sediments to overlying water accounted for only about 7.6% of annual DIN inputs and 1.0% of annual DIP inputs. High primary productivity (89 mol C m⁻² year⁻¹) supported by abundant nutrients primarily drove the lagoon into a hypertrophic condition as particulate organic matter was derived mainly from biological production. Excess of DIP appeared to occur throughout the study period in the lagoon. Temperature, solar radiation and turbidity, rather than nutrients, perhaps controlled seasonal variations of primary productivity. The net ecosystem production (NEP) derived from daily changes of DOC and POC inventories was about 6.3 mmol C m⁻² day⁻¹ that was close to 6.7 mmol C m⁻² day⁻¹ simulated from the biogeochemical modeling. Therefore, the net ecosystem production (NEP) rate of organic carbon estimated from the biogeochemical model was reliable, and the NEP was temporally variable with an annual mean of 5.8 mol C m⁻² year⁻¹, implying that Tapong Bay was an autotrophic system. Although calcification proceeded pronouncedly in warm seasons, an invasion of CO₂ was significant in this system. In terms of nitrogen budget, the annual nitrogen fixation exceeded the annual denitrification with a magnitude of 1.30 mol N m⁻² year⁻¹, which may be supported by the abundance of nitrogen fixation microplanktons in the lagoon.     

Residual circulation and sediment distribution in the Ria de Aveiro lagoon, Portugal

A two-dimensional hydrodynamic and sediment transport models have been developed and applied to the Ria de Aveiro lagoon, Portugal. The application consisted in the study of the residual circulation, the residence time as well as the sediment dynamics in the lagoon. High residence time for particles situated at the far end of the main channels points out that they are retained for a long time and tend to remain there, with high probability of being deposited into the bed. Low residence time for the central areas implies that the particles are flushed out more rapidly toward the lagoon mouth, revealing that the water and the particles exchange are very effective there. Although the residual circulation due to the rivers induces an overall transport toward the lagoon mouth, the residual circulations due to the winds induce particular circulation patterns (clockwise or counter-clockwise eddies) at some locations of the lagoon, depending on the wind direction. It was found that the suspended sediment concentrations along the main channels are induced by tidal asymmetries (resulting in areas of ebb and flood dominance), as well as by the wind stress and rivers runoff effects. They contribute, in general, to increase the sediment export toward the ocean, although the wind stress may induce currents and circulations in the opposite direction of the tidal currents. High turbid zones are observed for strong tidal currents, associated with tidal asymmetries, as well as with high rivers runoff. The erosion–deposition budget indicates a tendency for sediment accumulation at important areas of the lagoon, namely the shallow ones.     

平原地区某内河生态航道整治工程设计要点

传统的内河航道建设重点关注航运、灌溉、防洪排涝等功能,但随着经济与社会的不断发展,人们也越来越关注传统功能外的生态美、景观美、人与自然和谐的问题。以某内河航道整治工程为例,针对平面规划线型与现状线型差异大、文物保护要求和生态景观要求高、环保压力大等工程特点,通过对航道平面线型、护岸结构、文物保护、生态景观、节能环保等关键技术要点进行研究,提出自然型护岸线、生态型护岸、矩形航道断面的文物保护方案、节能环保的装配式护岸建造方案等设计对策,达到航道建设的生态美、景观美、人与自然和谐的效果。     

基于动态水域网格计算的船舶领域研究

为了满足现代船舶的发展需求,结合船舶自动识别系统(AIS)数据量巨大,包含了丰富的船舶信息等优点.本文利用SQL2012对AIS数据进行处理,建立包含船舶静态信息和动态信息的数据库;借助C#程序语言,构建以中心船舶为原点的网格坐标系,并以船舶间相对距离方位计算周围船舶在网格中的相对位置坐标;对同长度和类型的船舶进行网格叠加计算,并以船舶频数的方式进行统计,采用数据处理软件Matlab以最小二乘法的方式对统计结果进行处理;对研究水域的主要船型不同尺度的船舶领域进行对比和统计分析,并对不同船型船舶领域略作讨论,总结得出开阔水域船舶领域的特点.     

舰载雷达两轴转台稳定方程推导

舰载雷达两轴转台系统机械结构简单,可对雷达天线法线的姿态角进行控制以保证雷达波束指向,但在舰船发生摇摆时,雷达波束绕天线法线发生旋转.本文分析了大地直角坐标系和舰船直角坐标系的关系,在舰船直角坐标系中对舰载雷达两轴转台系统的姿态角进行定义,用空间解析几何法推导出已知舰船平台罗经信号、天线法线姿态角时两轴转台系统的稳定方程和波束旋转角方程,为舰载雷达两轴转台系统的伺服控制和波束相关补偿提供理论依据.     

Investigation of the condition and the behavior of a modular floating structure by harnessing monitoring data

In this paper, the condition and the behavior of an installed and operating Modular Floating Structure (MFS) is investigated and assessed by harnessing field monitoring data and using collectively multiple Correlation Coefficients (CCs) between measured quantities. The examined MFS consists of five pairs of interconnected floating concrete modules and it functions as a floating breakwater. The field monitoring data are acquired through a sensor network deployed on one pair of modules (connected through two groups of connectors) of the MFS. A methodological data processing framework for data organization, manipulation and post-processing is developed and presented. This framework enables the quantification of the structure's condition at different time periods through the calculation of CCs: (a) between the incident wave height and the tensions of the mooring lines and (b) between the tensions of the mooring lines, considering various wave directions. Recorded data at three characteristic time periods during the structure's lifetime are used, namely: (i) before any failure (structure's initial condition), (ii) after the failure of the first connectors' group and (iii) after the failure of the second connectors' group. The data processing framework developed in the present paper is applied to the above recorded data in order to calculate CCs and, therefore, quantify the structure's condition, at the three aforementioned time periods. The quantification of the structure's initial condition resulted to conclusions that were consistent from a physical point of view with the most recently documented, available in-situ mapping of the mooring lines' configuration in the horizontal plane. By considering the structure's initial condition as a reference base for comparison, the effect of the connectors' failure on the CCs, used to quantify this condition, was also investigated and efficiently assessed. Specifically, the significant changes observed in the variation patterns of all examined CCs, when compared with their respective patterns corresponding to the structure's initial condition, demonstrated and confirmed the existence of significant reformation of the examined structural system resulting from the connectors' failure. In this way, the effectiveness of the joint utilization of CCs to assess the structure's condition was proved.     

Assessment of coastal zone issues in the Republic of Korea

Abstract

The physical characteristics of Korea have had a profound impact on the uses of the coastal zone that have, in turn, been determined by and reinforced the nation's economic development strategy. While coastal zone management in many developed economies is more heavily oriented toward environmental protection and the resolution of user conflicts, policies for coastal zone management in Korea have emphasized the role of coastal space and other resources for economic development and industrial needs. Increasing demand for land reclamation to provide ever‐increasing industrial sites and human settlements, traditional and future needs of the fishery, and concern for the environment have led to a vast array of competition and, finally, often to conflicts. The basic pattern of coastal zone use in Korea has changed from the linear expansion of coastal zone to integrated coastal uses. An increased number of critical coastal zone issues and interactions was reflected in the creation of new governance that dealt with coastal zone resources and environment.     

Successful Transplantation of a Fragmenting Coral,Montipora digitata,for Reef Rehabilitation

The scleractinian coral Montipora digitata (Acroporidae) is a common reef flat species that thrives under high levels of light and water turbulence, and propagates successfully by natural fragmentation. It was used for transplantation experiments in an attempt to restore a degraded lagoon environment in the northwestern Philippines. Branches about 5 cm high from a natural population in the lagoon were transplanted to dead coral outcrops or knolls in two locations (Binlab and Malilnep-Ac) with different environmental characteristics. Growth and survival were significantly better at Malilnep Ac, which resembled the natural habitat of the species more closely. Environmental conditions at this site also favored the establishment of a greater diversity of species around the coral transplants. There was no difference in performance between transplants on vertical and horizontal surfaces, and the transplants showed limited differences due to density within the experimental range. Significant survival of detached, transplanted colonies or fragments thereof around the bases of the experimental bommies at the more successful site was an additional positive outcome. Water motion showed significant effects on survival and growth, possibly enhancing the suitability of the more successful site for transplantation. These results demonstrate the potential of coral transplantation to initiate the establishment of natural communities in degraded reef areas, a concern for coastal managers in developing countries.     

Legal Regulation of Land Reclamation in China's Coastal Areas

China's national marine development strategy acknowledges that land reclamation problems cannot be avoided. Land reclamation has increased rapidly, leading to many risks—as regards resources, the environment, and social concerns. China needs to implement measures to control these risks. Analysis of current legal regulations on land reclamation reveals paradoxes of legislation at the national level and varying regional legal practices; there is a shortage of effective and coordinated land reclamation regulations in China. Analysis of the factors that affect land reclamation shows that regulation plays a central role in managing land reclamation. And, through an analysis of the deficiencies in existing legislation and by learning from the experience of other countries, we can propose a direction for China's land reclamation legislation. Such reforms could effectively protect China's marine resources, avoid environmental and societal risks, and contribute to coastline protection.     

船后喷水推进器水下辐射噪声源脉动流场的数值计算

为避免尺度效应对噪声性能的影响,文章研究探索了在实尺度条件下装船后喷水推进器噪声声源的数值计算方法。首先,基于分离涡模型对国外某喷水推进泵内部非定常流场进行了数值模拟,将计算得到的不同转速下泵的功率值与厂商提供数据进行对比,最大误差在2.0%以内,验证了数值计算方法的准确性和有效性。其次,完成了实尺度条件下某"船体+喷水推进泵+进水流道"系统带自由液面的非定常流场的数值计算。提取了实船条件下喷水推进器流道进口处的不均匀速度场,将其加载到单个喷水推进器数值计算模型的进口边界。进而,采用分离涡模型对该船后"喷水推进泵+进水流道"内部非定常流场脉动压力进行数值计算,分析了各个特征截面压力脉动的频域特性,为下一步准确计算喷水推进器噪声提供了有效的脉动流场信息。     

Simplified analysis for estimation of the behavior of a submerged floating tunnel in waves and experimental verification

To achieve rational design in waves for a submerged floating tunnel which has emerged as a new offshore transportation infrastructure, it's necessary to understand its hydrodynamic behavior. For simple but accurate estimation of hydrodynamic forces, a theoretical method is proposed and the tests with physical models in a wave flume were carried out for verification. Morison's equation was used to estimate wave loads composed of inertia force and drag force. Forces calculated by applying the linear wave theory to Morison's equation coincided well with those measured by the tests. The test results showed that mooring systems played a significant role in the movement of the submerged floating tunnel in waves. A pendulum model could be used to describe the motion of the submerged floating tunnel with a single vertical mooring. Based on the verified relations, a simple slack condition which causes the submerged floating tunnel to be unstable was also proposed. The simplified approach proposed by this study proved to be useful in designing the submerged floating tunnel in the initial stage.     

Integrating visual management into the coastal zone planning process: The Massachusetts experience

Abstract

This paper concerns the limitations on integrating visual management into the coastal zone planning process as exemplified by the Commonwealth of Massachusetts, a state with a strong tradition of “home rule”; and a CZM implementation program based on a “networking”; of existing state authorities. The implications of the Massachusetts experience are that: (a) management of esthetic resources at the state level continues to be much less of a priority than management of ecological resources such as wetlands or floodplains; (b) visual management has yet to engender a strongly supportive constituency beyond that concerned with historic preservation; (c) project review focusing on visual impacts may be a more appropriate activity for local rather than state government; and (d) the technical aspects of visual management or impact assessment are far more advanced than their political acceptability. Political realities, together with the decision that implementation of the program should be based on a networking of existing authorities, thus determined the degree to which visual management could be incorporated into the state's program. As a result, the program's principal instruments of visual management became a strengthening of existing programs such as Wild and Scenic Rivers, reliance on wetland protection statutes to indirectly protect natural scenic values, and the use of the federal consistency provisions of the Coastal Zone Management Act to foster focused growth patterns through provision of publicly funded infrastructures. Esthetically oriented project review, with the exception of potential impacts on historic sites, was left to the discretion of local government, and a technical assistance program was created to provide funding or professional skills to communities interested in developing their own esthetic controls or design review processes. Maine, Rhode Island, and other New England states have followed a similar course.     

Community Fishery Resources Management on Malalison Island,Philippines: R & D Framework,Interventions, and Policy Implications

In 1991, the Aquaculture Department of the Southeast Asian Fisheries Development Center launched a community-based fishery resources management project on Malalison Island, in central Philippines, to help conserve the country's marine resources and to help the fisherfolk rise above their poverty. The eight-year project integrated various disciplines in biology, economics, sociology, public administration, and engineering in its study of fishery resources and fishing communities and in evolving intervention strategies for resource conservation and management, and for community development. The project's most important accomplishment was the inculcation among the fisherfolk of the importance of resource conservation and management. The most important lesson learned was that an enlightened and empowered fisherfolk could be effective managers and responsible users of fishery resources.     

耙吸挖泥船浅窄航道施工技术

针对耙吸挖泥船自身体积大、吃水深、不适宜浅窄水域施工的问题,进行了耙吸船浅窄航道施工技术研究。通过分析潮汐、水深条件、耙吸船特性、施工工艺等要素,得出结论：确保选定的船舶上线位置不仅要满足上线时刻的船舶航行挖泥水深需要,还要保证在施工航速下各个时段的船舶富余水深要求。该施工技术以船底富余水深为关键控制量,尽量延伸上线位置,保证可施工区段长度,逐渐拓展工作面,突破了耙吸船浅窄航道水域施工的技术瓶颈。