Impact of coupling coordination development of port and city environments on urban economic competitiveness:Evidence from the coastal port cities in eastern China

Promoting the coupling coordination development of port and its hinterland city environments is an important way to improve urban economic competitiveness.Based on relevant data of 13 coastal port cities in eastern China from 2000 to 2018,this study explores the coupling coordination development of port and city environments and its impact on urban economic competitiveness by constructing the coupling coordination degree model and the panel threshold model.The research results show that:(1)In terms of the coupling coordination development of port and city environments,most coastal ports and their hinterland cities are in a state of moderate or serious disorder.Overall,the degree of coupling coordination of port and city environments needs to be further improved;(2)The coupling coordination degree of port and city environments has a significant impact on urban economic competitiveness,and this effect gradually increases with the development of the ports and the urban economy.Among the variables that impact the urban economic competitiveness,fixed assets investment and foreign trade are significant factors that can enhance urban economic competitiveness.(3)At present,there is a“U-shaped”relationship between the coupling coordination degree of port-city environments and the urban economic competitiveness.This relationship lies on the right side of the inflection point of the“U-shaped”curve.Therefore,following the concept of assigning priority to ecological development,expanding fixed assets investment and actively developing foreign trade can further enhance the urban economic competitiveness.

Structural strength deterioration of coastal bridge piers considering non-uniform corrosion in marine environments

In the aggressive marine environment over a long-term service period,coastal bridges inevitably sustain corrosion-induced damage due to high sea salt and humidity.This paper investigates the strength reduction of coastal bridges,especially focusing on the effects of non-uniform corrosion along the height of bridge piers.First,the corrosion initiation time and the degradation of reinforcement and concrete are analyzed for bridge piers in marine environments.To investigate the various damage modes of the concrete cover,a discretization method with fiber cells is used for calculating time-dependent interaction diagrams of cross-sections of the bridge piers at the atmospheric zone and the splash and tidal zone under a combination of axial force and bending moment.Second,the shear strength of these aging structures is analyzed.Numerical simulation indicates that the strength of a concrete pier experiences dramatic reduction from corrosion initiation to the spalling of the concrete cover.Strength loss in the splash and tidal zone is more significant than in the atmospheric zone when structures’service time is assumed to be the same.

Resource and Environmental Quality Changes and Adjustment Principles for Sustainable Development in Rapidly Developing Coastal Region of Southeastern China

Problems in water-land resources and environmental quality increase with the fast economic development in the coastal region of southeastern China. This region has the highest density in population, industry and towns in China, and the large export-oriented economy makes itself a strategic importance while China enters into international markets. The problems facing to this region include arable land reduction, land degradation aggravation, high percentage of built-up land with high rate of expansion, expanded non-point pollution, deteriorated water quality, decreasing biodiversity, destroyed ecosystems, severe air pollution, frequently occurred acid rain, and multi-pollutants. The important research fields in the near future should include a) influence of high-intensity exploitation of resources on changes of environment quality and its feedback; b) interface processes, key mechanisms and adjustment principles for degradation of water-, land-, and air-resources and environmental quality; c) evolvement processes and nurturing theory of biodiversity and ecological resources; and d) spatio-temporal variation and human-induced effects on regional resources and environment quality. Strategies for sustainable development in the region are as follows: a) controlling to ensure basic cultivated land area; b) enforcing remediation of polluted water environment, and controlling non-point pollution; c) strengthening ecological construction and ecological security; and d) controlling multi-pollution and preventing trace toxic pollutants.

Spatio-temporal Difference and Influencing Factors of Environmental Adaptability Measurement of Human-sea Economic System in Liaoning Coastal Area

Adaptability theory is an important tool to analyze the degree, mechanism and process of interaction between human and environment, which provides a new perspective for the research of sustainability assessment. Based on the entropy weight-TOPSIS method and the panel Tobit model from the perspective of adaptability, spatio-temporal difference and influencing factors of environmental adaptability assessment of human-sea economic system in Liaoning coastal area was measured by using the city panel data from 2000 to 2014. The results indicate that: 1) The environmental adaptability of human-sea economic system in Liaoning coastal area rose slowly from 2000 to 2014, the developing trend of each city was linearly related, and Dalian was in a leading position. 2) The different adaptability elements and adaptability subsystem show polarization phenomenon and completely different regional evolution characteristics. The adaptability of human-sea environment system and human-sea economic system rose slowly and had the characteristics of linear relationship, and the adaptability of human-sea environment system is the main reason for the difference of environmental adaptability of human-sea economic system. 3) Science and technology, environmental management, marine economic development level, port construction are the driving factors of the healthy development of environmental adaptability of urban human-sea economic system.

Drivers of Change in Estuarine and Coastal Marine Environments: An Overview

Anthropogenic climate and non-climate drivers of change are causing significant impacts on estuarine and coastal marine environments. Climate change poses a particular threat to the structure and function of biotic communities in these environments because it acts on the most extensive temporal and spatial scales relative to other anthropogenic drivers of change. The interaction of multiple environmental drivers exacerbates degradation of ecosystem condition. Estuaries are most susceptible to climate-change mediated biotic shifts and direct anthropogenic impacts due to burgeoning human population growth and development in coastal watersheds. Multiple anthropogenic drivers of change, which often interact synergistically, alter physical, chemical, and biological characteristics. Ecological responses may be increasingly nonlinear, with cumulative effects manifested by marked changes in organism abundance, distribution, diversity, and productivity. Detrimental biotic effects in impacted coastal environments cascade up from individual organisms to population and community levels, culminating in ecosystem-level changes including reduced services. Multiple drivers of change and their impacts are increasing in estuarine and coastal marine environments with greater anthropogenic forcing in the coastal zone and global effects of climate change, creating greater challenges for environmental management and conservation programs.

Economic development and its impact on the environment in east coastal zone of China

This paper discusses briefly the elementary characteristics of the east China economic developing zone, and analyses the condition of urban atmospheric pollution, water pollution and ecological damage in this zone at present. It was brought forward that we must pay great attention to the environmental factors, and make the environmental impact assessment and environmental planning in the process of economic development in this zone.

Global path planning methods of UUV in coastal environment

In coastal environment,the motion of unmanned underwater vehicle(UUV)is influenced significantly by complex current.The operational performance of UUV can be greatly improved when the impact of ocean current is considered.A global path planning method of the static obstacle environmental space is addressed in the paper.Firstly,according to the typically coastal vortex,a model of ocean current is proposed and the influence to the motion of UUV is analyzed.Secondly,to satisfy the rapid requirement in path planning,a heuristic A*algorithm is used to design global planning path with multiple constraints.Besides,to meet the UUV’s smooth path requirement,Bezier curve theory is applied.Simulation experiments are performed to illustrate the feasibility of the algorithm in the steady current and vortex environment.

Empirical Assessment of Coastal Environmental Vulnerability to Sea Level Rise

Sea level rise (SLR) could critically endanger the environment along all the world’s sea coasts. Although sudden SLRs of meters-high waves that might have apocalyptic results would generally be limited to specific areas, on-going SLR of dozens of cms over decades is likely to have adverse impact on coastal environments throughout the world. This study’s objective is to assess relative regional vulnerability of global sea coasts to SLR. The study focuses upon key natural and anthropogenic parameters that might either cause or enhance SLR and thus significantly influence regional coastal environments. Careful assessment can enable reasonable estimates of relative vulnerability of such environments. An initial step involves specifying key parameters and assigning their weightings and ratings. To demonstrate the feasibility of this approach, six seacoast regions from various parts of the world have been considered in this paper, assessing their natural and anthropogenic parameters vis-à-vis general global data. The results emphasize the relative vulnerability of these areas’ environments to SLR. Recommendations are then made for improving global SLR modeling and monitoring.

Management Strategies to Mitigate Anthropogenic Impacts in Estuarine and Coastal Marine Environments: A Review

A wide range of anthropogenic activities impacts estuarine and coastal marine environments including interactive climate and non-climatic drivers of change that can significantly degrade biotic communities and habitats. Many of these environments are in decline due to changes in ecosystem structure and function resulting from multiple stressor effects. In addition, inadequate governance has supported a patchwork of single issues or sectoral approaches rather than integrated management of multiple human uses and activities to maintain healthy, productive, resilient, and sustainable ecosystems and the provision of goods and services. Ecosystem-based marine spatial planning is a viable framework for a more effective governance structure and management of these vital coastal environments. An important component of this approach is a holistic effort to assess the environmental, economic, and societal impacts of anthropogenic activities. Thus, a multidisciplinary integrated approach is preferred that links ecological, physical, and socio-economic systems, increasing the protection of resources and societal benefits. For degraded estuarine and coastal marine ecosystems, restoration and rehabilitation initiatives are important intervention strategies used to reverse the loss of habitats and biotic resources and to support management programs. Marine Protected Areas (MPAs) are an integral element of marine management plans to conserve and sustain estuarine and coastal marine environments by protecting threatened ecosystems and their resources from anthropogenic activities. National and international regulatory frameworks and directives are also in place to protect and conserve these environments.

Knowledge and Opportunities from the Plastisphere:A Prelude for the Search of Plastic Degrading Bacteria on Coastal Environments

Plastic pollution has become an urgent issue,since its invasion to everyecosystem has led to multiple impacts on the environment and human pop-ulations.Certain microbial strains and genera had shown the ability to bio-degrade plastic sources under laboratory conditions.In this minireview,wecallect and analyze scientific papers and reports of this microbial activity aswe contextualize this information on the global plastic pollution problem,toprovide an updated state of the art of plastiq/biodegradation with microbialagents.Along with a broad understanding of the general process of plasticbiadegraclation hosted by micrnarganisms.The contributions of this mini-revicw came from the identification of rescarch gaps,as well as proposalsfor new approaches.One of the main proposals focuses on coastal environ-nents and in particular coastal wetlands as a great microbiome source withpatential for plastic biodegradation,whether reported or undiscovered.Ourfinal proposal consists of the application of this knowledge into technologictools and strategies that have a remarkable impact on the battle against theplastic pollution problem.

Temporal Variations of the Chemical Composition of Three Seaweeds in Two Tropical Coastal Environments

The seaweeds Chaetomorpha antennina, Gymnogongrus griffithsiae and Ulva fasciata were studied regarding tissue concentrations of total nitrogen, total phosphorus, total protein, hydrosoluble protein, total carbohydrate, chlorophyll a and total carotenoid throughout a 39-month survey in two coastal environments of Rio de Janeiro State, Brazil. One of the sites (Itapuca Stone) has high concentrations of dissolved nutrients and an intense long-term process of cultural eutrophication;the second site (Bananal Inlet) is thought to have lower concentrations of dissolved nutrients and no relevant anthropic impact. Seaweeds experienced changes in the concentrations of the substances in the thalli;however they did not show any cyclic seasonal pattern, except for pigments, with lower values in summer in both sites. The differences found for each species in each sampling at the sites were small (e.g. U. fasciata, more total nitrogen at Itapuca Stone) or absent (e.g. C. antennina, no significant differences for hydrosoluble protein in the sites). Differences in the concentrations of dissolved nutrients in the sites did not generate contrasting chemical profiles in the seaweeds. There is no evidence of nitrogen- or phosphorus-limitation in any season. It is presumable that the concentrations of dissolved nutrients at the nutrient-poorer site are sufficient to generate high concentrations of the substances in the thalli of the species tested, similar to the concentrations measured in the eutrophic site. Experimental data are needed to elucidate the factors that promote the success of the species tested under contrasting nutrient availability and environmental disturbance.

Concentration of Heavy Metals in Sediment and Seagrasses Tissue of the Red Sea Coastal Water of the Sudan

The study investigated the concentration of Lead, Cadmium, Nickels and Chromium in sediment and seagrass tissues at six selected sites along the Sudanese Red Sea coast. The findings of the study added some important and necessary information about the status and condition of the coastal environment in the Sudanese Red Sea coast in terms of the extent of pollution with heavy metals. The study sites included: Marsa Bashayer, Marsa Dama Dama, Green Area, Shipyard, Marsa Halout and Dungonab Bay. The Atomic Absorption Spectrophotometer was used to measure Lead, Cadmium and Nickels. The colorimetric detection method was used for Chromium using the Spectrophotometer. Marsa Dama Dama site revealed high levels concentration of heavy metals in sediment for Lead (60.5) μg/g, Cadmium (0.22) μg/g and Chromium (146.65) μg/g. Marsa Halout showed the highest mean concentration of Nickel in sediment at 14 μg/g. The variation of concentration of metals in sediment between the sites was not significant. The mean concentration of metals in seagrass species tissues ranged from 3.9 to 26.25 μg/g for Lead, 0.1 to 0.90 μg/g for Cadmium, 0.38 to 5.96 μg/g for Nickel and 0.15 to 0.495 μg/g for Chromium. The differences of concentration of heavy metals in seagrass tissues among the sites were significant for Lead and not significant for Cadmium;Nickel and Chromium.

Natural and Artificial Connections between Atoll Islets in the Pacific,Their Process and Environmental Impact

Three types of natural connection between atoll islets are described. Causeway, as an artificial way of connecting islets, makes a connection to be completed in a few months. In this case shore adjustment becomes more vigorous than that in natural conditions, resulting in lagoon shore erosion. A causeway without short bridges or culverts should be built close to the lagoon shore to reduce lagoon shore erosion. A causeway-crossing channel assemblage is the worst type among all of the connection engineering constructions because the crossing channel traps sediment and further transports it out of the channel, resulting in long period coastal erosion. Reforming Nippon Causeway in Tarawa Atoll, Kiribati by simple means will stop sand loss, reduce shore erosion and greatly upgrade its stability.

Historical Evolution of Mariculture in China During Past 40 Years and Its Impacts on Eco-environment

The rapid development of mariculture in China in recent decades has satisfied people's demand of seafood, and has made a great contribution to economic development. However, mariculture has also caused some negative impacts on the eco-environment. By statistically analyzing national data(as well as data for four main provinces) regarding the mariculture area and cultivation species in China since reform and opening up, the historical evolution of mariculture during the past 40 years was analyzed, the driving factors related to policy, market and technology innovation were discussed, and the potential impacts of mariculture on the coastal eco-environment were also illustrated. The statistical results indicated that the maricultural area increased radically during the past 40 years, from 1979(116.47 × 10~3 ha) to 2012(2205.65 × 10~3 ha), with an increase of nearly 20-fold. Shandong Province represented the fastest-growing region, with an increase of 31-fold. Moreover, the cultivated species had gradually become diversified. Initially, shellfish and algae were major species, and then it developed to various species including fish, and currently shellfish and crustaceans were the major species. The development of mariculture was driven by government policies, market economy and technology innovation. Rapid development of mariculture also caused significantly adverse impacts on the eco-environment of the coastal regions. For example, the sea reclamation for mariculture decreased the area and function of coastal wetlands and the contaminants originating from mariculture destroyed the coastal aquatic environment. Fortunately, the implementation of ‘13 th Five-Year Fisheries Planning' is expected to help both improve the seafood quality and reduce the contamination in coastal aquatic environment. This current study will provide reference for management and structure adjustment of mariculture in the future.

长江三角洲北翼更新世以来的水土环境地球化学特征及其环境指示意义

江苏沿海平原是江苏省域水资源脆弱带,地下水咸化已成为较为严重的生态环境问题。为了解析长江三角洲北翼地区更新世以来地下水的补给及其盐分来源,布设一口275 m的深井HYRD1,全孔连续采集易溶盐样品、土工样品、水样。在区域采集地表水、浅层与深层地下水、海水样品。采用易溶盐指标结合土工指标(含水率、湿密度、比重)获取了HYRD1高精度孔隙水的水化学特征。采用Piper三线图、Gibbs图、离子比值法等结合δD、δ^(18)O数据、^(14)C测年数据解析了更新世以来地下水的补给及其盐分来源。结果表明:土体盐分主要为NaCl,盐渍土占比为25%。盐渍土主要分布在Q_(p3)弱透水层、 Q_(p2)地层与Q_(p1)上段地层。孔隙水水化学类型为Cl-Na型(仅Q_(p1)下段个别点为HCO~-_3-Ca·Na),微咸水占比7%,咸水占比49%,盐水占比44%。微咸水主要分布在Q_(p1)下段砂层中。潜水的δ^(18)O、δD说明潜水来源为大气降水,且受到了较为强烈的蒸发作用。弱透水层孔隙水、承压水的δ^(18)O、δD投点位于标准海水稀释线附近,且随着深度的增加,δ^(18)O、δD有减小趋势,说明海水混合作用随着深度的增加而减小。Q_(p1)弱透水层多见钙质结核,说明了Q_(p1)地层成土后受到了强烈的蒸发作用。HYRD1 Q_(p1)上段及上覆地层盐分主要来源于5期海侵、蒸发盐岩与硅酸盐风化溶解,Q_(p1)下段地层盐分主要来源为地壳源。地下水化学成分受到了水岩作用、蒸发浓缩作用与人类活动等的影响。

沿海省份城市发展活力评价及其互动关系研究——以副省级城市为例

以德鲁克社会创新为理论基础,基于城市内三大行为活动主体构建包含人居环境、营商环境、治理环境系统的发展活力评价指标体系,利用多因子分层动态激励模型对2006—2020年我国沿海省份8个副省级城市的发展活力进行评价,运用耦合协调模型和面板向量自回归模型分别测度并分析3个子系统间的耦合协调情况和互动关系。结果表明:(1)各城市的发展活力由高到低依次为广州、深圳、杭州、南京、青岛、宁波、大连、厦门,城市间发展活力综合评价结果两极分化明显,营商环境是影响城市发展活力提升最重要的因素,人居环境次之,治理环境最小。(2)8个城市的耦合协调级别不高,整体处于失调类型。(3)3个系统间相互作用,但其发展水平主要受自身影响。其中,人居环境系统显著受其他两个系统影响;营商环境系统受治理环境系统影响较强;治理环境系统主要依靠自身调节,受其他系统的影响较小。

福建长乐海域水沙环境及海岸演变研究

依托实测水下地形和水文泥沙资料,研究了福建长乐海域水沙环境及海床冲淤演变特征。研究结果表明:福建长乐海域为基岩岬角控制的沙质海岸,波浪较强、潮流流速小、水体含沙量低、海岸线及海床地形长期保持基本稳定状态;研究海域的常风向和常浪向均为NNE向,强风和强浪主要受台风及寒潮大风影响;研究海域属强潮海区,最大潮差为6.92 m,平均潮差为4.45 m;研究海域潮流属正规半日潮流,往复流特征明显;研究海域底质分布在横向上呈现近岸粗、深水区细的分布特点,近岸存在南北连续的砂质沉积带,波浪作用下自北向南输移的泥沙对海岸演变有一定影响。

变化环境下长江流域滨海城市供水安全与适应性对策

全球气候变化和高强度人类活动影响导致长江流域水循环变化及相关联的城市群水资源供需矛盾问题,尤其在长江下游上海等滨海城市供水安全问题更加凸显,这已成为长江大保护十分关注的重要问题之一。以典型滨海城市上海为例,重点论述变化环境对长江流域的供水安全风险问题;分析当前和未来上海城市供水极端干旱影响、长江淡水与河口咸潮互动供水窗口压力,以及上海城市供水管理综合运用工程措施和预警预报、调度等非工程措施的挑战;提出若干对策与建议,包括供水安全保障的系统思维与战略规划、提升城市供水安全的系统智能化与智慧化管理水平以及完善供水安全保障的管理体系。

港城环境协调发展对城市经济竞争力影响的门限效应分析

基于2000~2021年中国东部地区13个沿海港口城市相关数据,构建协调度模型和面板门限模型,探析港城环境协调发展及其对城市经济竞争力的影响。研究结果表明:1)在港城环境协调度等级上,东部地区大多数港口与其腹地城市处于中度失调或严重失调阶段,整体上港城环境协调发展程度有待提升;2)港城环境协调度对城市经济竞争力具有显著影响,并且随着港口和城市经济发展,这种影响效应略微减弱,在协调度的影响变量中,固定资产投资、对外贸易是提升城市经济竞争力的显著因素;3)目前沿海港口城市港城环境协调度和城市经济竞争力之间呈“U”型关系,且处于“U”型曲线拐点右侧,因此,需坚持生态优先发展理念、扩大固定资产投资和积极发展对外贸易,以进一步提升城市经济竞争力。

粤东大亚湾水沙环境及岸滩演变分析

根据现场实测水文泥沙及地形资料,对大亚湾海域的自然条件、水沙环境特征及岸滩演变特征进行分析,研究结果表明:大亚湾潮差较小,波浪和潮流动力弱,水体含沙量较低,泥沙来源有限,主要来自近岸附近滩面就地搬运的少量泥沙。湾内底质多为黏土质粉砂,呈现淤积质海岸的沉积特点。因此大亚湾海域水清沙少,自然状态下海床长期保持稳定。近期受港口航道建设、围填海等人类活动的影响,部分海床地形出现较大幅度的冲淤变化。湾内港池、航道疏浚开挖后航槽稳定,回淤强度较小。正确认识该海域的水动力条件、泥沙运移及海床冲淤变化,不仅是开展海岸工程开发建设的关键技术问题,也有利于近岸海洋环境保护及资源开发利用。