河口海岸GIS时空过程可视化表达

河口海岸带中一些随时间变化的三维海洋现象(如涡漩、锋面、水团等)的时空建模与可视化表达是海洋地理信息系统(MGIS)发展的一大难题。基于流体建模与可视化AVIZO Green技术,针对海洋连续场中的三维海洋现象,提出了基于特征的时空三域动态识别技术,设计并实现了面向主题应用的时空四维GIS可视化框架,能够有效表达三维海洋现象。以长江口海岸带涡漩、冲淡水、羽状锋和盐跃层为例进行三维动态可视模拟,直观再现了object-like型和field-like型海洋现象的时空演绎过程,为海洋现象仿真研究,尤其是多维、动态、边界模糊的复杂海洋现象的有效表达提供了一种新思路和方法。     

Evaluating Adaptive Processes for Conservation and Management of Estuarine and Coastal Resources

This special feature: Genetic Structure and Adaptation in Coastal Ecosystems emphasizes the importance of research focused on population genetic structure and evolutionary change for understanding estuarine and coastal communities. Many studies have examined the effect of environmental gradients on community-level patterns in estuarine habitats; however, relatively little is known about the role of genetically based adaptation (the heritable response to these environmental gradients) in these organisms. This special feature presents 11 studies that use a variety of approaches including ecophysiology, ecological genetics, molecular markers, and patterns of gene expression occurring within these populations. These studies provide examples of the role of genetic diversity and adaptation across a diversity of estuarine and coastal environments, and highlight the temporal and spatial scales at which adaptation impinges upon management. This collection of papers is especially timely, given the increasing importance of understanding and predicting the response to global climate change in order to effectively manage these communities.     

Contrasting Bacterial Dynamics in Subtropical Estuarine and Coastal Waters

Seasonal succession and composition of both attached and free-living bacterial communities were studied in subtropical estuarine and coastal waters with contrasting hydrographic conditions. A higher abundance of attached bacteria was recovered in the estuarine waters containing high concentrations of dissolved organic carbon (DOC) resulting from the freshwater discharge in the adjacent Pearl River, and Proteobacteria, including ??-, ??-, and ??-groups, predominated the attached community at both stations. Free-living bacterial communities at both stations showed higher diversity and lower seasonality than their attached counterparts, and ??-Proteobacteria accounted for the highest proportion at both stations. Redundancy analysis (RDA) demonstrated that, in addition to the obvious temperature effects, DOC and microphytoplankton (>20???m Chl a) drive the temporal variation of attached bacteria at the estuarine and coastal stations, respectively. On the other hand, picophytoplankton (<2???m Chl a) and dissolved oxygen concentration explained most of the free-living bacterial community succession at the estuarine station, while those at the coastal station were associated with micro- and picoplankton (Chl a fractions of <2 and >20???m). These findings suggest that temperature and bottom?Cup effects play a more important role for the spatial?Ctemporal variations of both attached and free-living bacterial communities in the subtropical estuarine and coastal waters.     

Oxygen and Nutrient Exchanges at the Sediment-Water Interface: a Global Synthesis and Critique of Estuarine and Coastal Data

Estuarine and coastal marine sediment-water fluxes are considered to be important ecological features, but a global-scale assessment has yet to be developed. Goals of this work were to assemble a global-scale database of net sediment-water flux measurements, examine measurement techniques, characterize the geographic distribution and magnitude of sediment fluxes, explore the data for controls on sediment flux magnitude, and assess the importance of sediment fluxes in ecosystem-level metabolism and primary production. We examined 480 peer-reviewed sources and found sediment flux data for 167 estuarine and coastal systems. Most measurements were made in North America, Europe, and Australia. Fluxes varied widely among systems, some by several orders of magnitude. Inter-annual variability within sites was less than an order of magnitude but time series flux data to evaluate this were rare. However, limited time series data exhibited large and rapid responses to decreased external nutrient loading rates, climate change effects (possible temperature effects), and variability in trophic conditions. Comparative analyses indicated organic matter supply to sediments set the upper limits of flux magnitude, with other factors playing secondary roles. Two metrics were developed to assess ecosystem-level importance of sediment-water fluxes. Sediments represented 30% or more of depth-integrated rates of aerobic system respiration at depths of <10 m. An annual phytoplankton production data set was used to estimate N and P demand; sediments supplied an average of 15–32% of N and 17–100% of P demand and, in some cases, was as large or larger than external nutrient inputs. The percent of demand supplied by sediments was highest in temperate latitudes and lower in high and tropical latitudes.     

Searching for metadata using knowledge bases and topic maps in Spatial Data Infrastructures

Concern for environmental issues has become a reality in all sectors of society, mainly among researchers and professionals who work directly with environmental status. In this context, several studies have been undertaken on sustainable development of the Brazilian Amazon, generating a large amount of data and information. Environmental area characterization involves the knowledge about their natural, economic and social resources, as well as understanding the interaction and correlation among them. Such interdisciplinary character requires new solutions for knowledge representation. This study proposes to minimize metadata recovery problems in Spatial Data Infrastructures by using Topic Maps and Thesaurus. This approach applied to an interface aims to allow users to visually recover information from metadata catalogs.     

基于遥感和GIS的上海市滩涂湿地资源近期变化分析

利用多期Landsat-5 TM影像,结合植被分带信息、地物波谱特征和实地调查数据,提取上海地区滩涂湿地分布及其覆盖信息;在ArcGIS软件支持下,综合多期遥感影像解译结果和相应时段的水下地形信息,对上海市滩涂湿地空间分布及其变化进行分析。结果表明,近15年来上海市滩涂围垦量在不断增加;尽管滩涂湿地仍在继续淤涨,但淤涨速度明显减缓,且慢于围垦速度,这导致中高潮滩涂面积不断减少。     

The Invasive Species Challenge in Estuarine and Coastal Environments: Marrying Management and Science

Despite the widely acknowledged threat posed by invasive species in coastal estuaries, there are substantial gaps at the intersection of science and policy that are impeding invasive species management. In the face of pressing management needs in coastal and estuarine environments, we advocate that introduced species should receive the kind of management effort dedicated, for example, to reducing pollution. We support our argument with some examples of economic costs of estuarine and coastal introduced species and a summary of recent evidence for the ecological costs. We highlight some of the issues that either thwart or facilitate the successful marriage between science and management of introduced species, including the regulatory framework for management. We use the available information on coastal eradication programs, including case histories of the programs for Caulerpa taxifolia and Spartina alterniflora (and hybrids) in the western USA, to indicate the feasibility of managing introduced species and to help point out how management and science can improve the outcome. We close with a research agenda that focuses primarily on science that will really assist with invasive species management and reflects our own experience and the opinions of managers directly involved with this issue.     

Ecological Signatures of Anthropogenically Altered Tidal Exchange in Estuarine Ecosystems

One of the most conspicuous anthropogenic disturbances to estuaries worldwide has been the alteration of freshwater and tidal influence through the construction of water control structures (dikes, tide gates, culverts). Few studies have rigorously compared the responses of differing groups of organisms that serve as contrasting conservation targets to such anthropogenic disturbances in estuarine ecosystems. Elkhorn Slough in central California includes a spectrum of tidally restricted habitats behind water control structures and habitats experiencing full tidal exchange. To assess community composition for several different taxa in habitats with varying tidal exchange, we employed a variety of field approaches and synthesized results from several different studies. Overall, we found that communities at sites with moderately restricted tidal exchange were fairly similar to those with full tidal exchange, but those with extremely restricted tidal exchange were markedly different from other categories. These differences in community composition are likely the result of several factors, including restricted movement due to physical barriers, differences in water quality characteristics, and differences in habitat structure. Indeed, in this study, we found that water quality characteristics strongly vary with tidal restriction and may strongly influence patterns of species presence or absence. We also found that different conservation targets showed contrasting responses to variation in tidal exchange. Full exchange appears to favor native oysters, commercially valuable flatfish, migratory shorebirds, and site-level biodiversity. Minimal tidal exchange due to water control structures supports a suite of estuarine endemics (including the tidewater goby and California brackish snail) not represented elsewhere and minimizes invasions by non-native marine species. Altogether, our results suggest that total estuary-wide biodiversity may be enhanced with a mosaic of tidal exchange regimes.     

Medium- and Long-term Recovery of Estuarine and Coastal Ecosystems: Patterns,Rates and Restoration Effectiveness

Many estuarine and coastal marine ecosystems have increasingly experienced degradation caused by multiple stressors. Anthropogenic pressures alter natural ecosystems and the ecosystems are not considered to have recovered unless secondary succession has returned the ecosystem to the pre-existing condition or state. However, depending upon the scales of time, space and intensity of anthropogenic disturbance, return along the historic trajectory of the ecosystem may: (1) follow natural restoration though secondary succession; (2) be re-directed through ecological restoration, or (3) be unattainable. In order to address the gaps in knowledge about restoration and recovery of estuarine and coastal ecosystems, this special feature includes the present overview and other contributions to provide a synthesis of our knowledge about recovery patterns, rates and restoration effectiveness. From the 51 examples collated in this contribution, we refine the recovery from the list of stressors into six recovery mechanisms: (1) recovery from sediment modification, which includes all aspects of dredging and disposal; (2) recovery by complete removal of stressors limiting natural ecosystem processes, which includes tidal marsh and inundation restoration; (3) recovery by speed of organic degradation, which includes oil discharge, fish farm wastes, sewage disposal, and paper mill waste; (4) recovery from persistent pollutants, which includes chemical discharges, such as TBT; (5) recovery from excessive biological removal, related to fisheries and (6) recovery from hydrological and morphological modification. Drawing upon experience both from these many examples and from an example of one comprehensive study, we show that although in some cases recovery can take <5 years, especially for the short-lived and high-turnover biological components, full recovery of coastal marine and estuarine ecosystems from over a century of degradation can take a minimum of 15–25 years for attainment of the original biotic composition and diversity may lag far beyond that period.     

Evolving Paradigms and Challenges in Estuarine and Coastal Eutrophication Dynamics in a Culturally and Climatically Stressed World

Coastal watersheds support more than one half of the world’s human population and are experiencing unprecedented urban, agricultural, and industrial expansion. The freshwater–marine continua draining these watersheds are impacted increasingly by nutrient inputs and resultant eutrophication, including symptomatic harmful algal blooms, hypoxia, finfish and shellfish kills, and loss of higher plant and animal habitat. In addressing nutrient input reductions to stem and reverse eutrophication, phosphorus (P) has received priority traditionally in upstream freshwater regions, while controlling nitrogen (N) inputs has been the focus of management strategies in estuarine and coastal waters. However, freshwater, brackish, and full-salinity components of this continuum are connected structurally and functionally. Intensification of human activities has caused imbalances in N and P loading, altering nutrient limitation characteristics and complicating successful eutrophication control along the continuum. Several recent examples indicate the need for dual N and P input constraints as the only nutrient management option effective for long-term eutrophication control. Climatic changes increase variability in freshwater discharge with more severe storms and intense droughts and interact closely with nutrient inputs to modulate the magnitude and relative proportions of N and P loading. The effects of these interactions on phytoplankton production and composition were examined in two neighboring North Carolina lagoonal estuaries, the New River and Neuse River Estuaries, which are experiencing concurrent eutrophication and climatically driven hydrologic variability. Efforts aimed at stemming estuarine and coastal eutrophication in these and other similarly impacted estuarine systems should focus on establishing N and P input thresholds that take into account effects of hydrologic variability, so that eutrophication and harmful algal blooms can be controlled over a range of current and predicted climate change scenarios.     

中国西部环境与生态科学数据中心：面向西部环境与生态科学的数据集成与共享

国家自然科学基金委员会“中国西部环境与生态科学研究计划”自2001年启动以来,有力地推动了西部区域环境演化、陆地生态过程和人类活动对环境的影响等方面的研究,积累了丰富的基础数据。国家自然科学基金委员会“中国西部环境与生态科学数据中心”承担“西部计划”项目数据产出的收集、管理、集成,并面向西部环境与生态科学的各个领域提供科学数据服务。“西部数据中心”的总体框架是以“西部计划”和地球系统科学发展的科学需求为导向,建成以数据共享、知识积累、合作交流和数据科学为主要内容的集成平台,为“西部计划”多学科的交叉研究和成果的综合集成及地球科学发展的长远目标服务。以共建共享的指导思想集成针对西部环境与生态现状与变化的基础背景数据、环境与生态观测数据、模型数据集、数据工具及数据文档;并以完全与开放的数据共享原则为用户提供推送式数据服务。目前,“西部数据中心”已完成了数据共享平台、知识积累平台与合作交流平台的开发和集成,初步形成了科学数据平台,整理并发布了大量的西部环境生态科学所需的关键数据集。     

Direct and Indirect Effects of Estuarine Reclamation on Nutrient and Metal Fluxes in the Global Coastal Zone

We demonstrate that land reclamation in estuaries is resulting in very large-scale loss of intertidal area and disconnection of stored sediment with the water column. This process is not just causing loss of estuarine ecosystem services, it is also having a major deleterious impact on the ability of estuaries to retain nutrients and trace metals. The global scale of loss of estuarine wetlands and subtidal sediments has reached the point where the impact of this loss of estuarine retention is likely to be affecting coastal seas worldwide and possibly global element cycles.     

水文基础设施建设形势与任务浅析

近年来,水文基础设施建设得到明显加强,水文站网布局和功能逐步完善,水文基础设施整体水平不断提高,水文测报和信息服务能力显著增强。经济社会发展和水利工作对水文不断提出了新的更高的要求,需要进一步加强水文基础设施建设。总结了"十一五"以来全国水文基础设施建设取得的成就,结合经济社会发展和水利工作对水文的要求,阐述了水文基础设施建设面临的形势和问题,分析了水文基础设施建设的目标和任务。     

Coastal Ecological Risk Assessment: Its Research Progress and Prospect

Coastal areas are located in marine-terrestrial interlaced zone. With their unique geographical positions, the coastal ecological risk assessment has both the complexity of regional ecological risk assessment and its own particularity. In recent years, due to the coastal economic development and the deterioration of ecological environment, coastal ecological risk has received more and more attention, but there are still lacking in further systematic study about the coastal ecological risk assessment. With the summary and analysis of the existing research results from home and abroad, based on land-ocean interaction plan and full consideration of the uniqueness, regionalism and complexity of the coastal zone environment, this paper made scientific conclusion on the definition of the coastal ecological risk assessment concept and its components from risk source, habitat and risk suffer-the three basic elements. Moreover, from risk source, risk suffer and comprehensive evaluation-the three aspects, it discussed in detail the related research topics, progress as well as main conclusions. Then, it analysed the characteristics and evaluation methods, and put forward the framework model of coastal ecological risk assessment. Finally, it analysed and proposed the existing deficiencies and future research direction, providing new ideas for future research on coastal ecological risk assessment.     

Impacts of Coastal Land Use and Shoreline Armoring on Estuarine Ecosystems: an Introduction to a Special Issue

The nearshore land-water interface is an important ecological zone that faces anthropogenic pressure from development in coastal regions throughout the world. Coastal waters and estuaries like Chesapeake Bay receive and process land discharges loaded with anthropogenic nutrients and other pollutants that cause eutrophication, hypoxia, and other damage to shallow-water ecosystems. In addition, shorelines are increasingly armored with bulkhead (seawall), riprap, and other structures to protect human infrastructure against the threats of sea-level rise, storm surge, and erosion. Armoring can further influence estuarine and nearshore marine ecosystem functions by degrading water quality, spreading invasive species, and destroying ecologically valuable habitat. These detrimental effects on ecosystem function have ramifications for ecologically and economically important flora and fauna. This special issue of Estuaries and Coasts explores the interacting effects of coastal land use and shoreline armoring on estuarine and coastal marine ecosystems. The majority of papers focus on the Chesapeake Bay region, USA, where 50 major tributaries and an extensive watershed (~ 167,000 km²), provide an ideal model to examine the impacts of human activities at scales ranging from the local shoreline to the entire watershed. The papers consider the influence of watershed land use and natural versus armored shorelines on ecosystem properties and processes as well as on key natural resources.     

The Response of Estuarine Macrobenthic Communities to Natural- and Human-Induced Changes: Dynamics and Ecological Quality

Anthropogenic activities are a disturbance factor of coastal systems and can be widely recognized as a major threat to the health of coastal systems. However, natural events cannot be disregarded from management issues because of their significant influence on the communities living in these areas. Based on long-term subtidal data from the Mondego Estuary (Portugal), the effects of natural events (e.g., floods and droughts) on macrobenthic communities were compared with the anthropogenic events. Sampling stations were grouped into characteristic zones (mouth, north arm, south arm) so the community dynamics of each of these estuarine areas could be followed over time. Environmental assessment was performed for stations using the Benthic Assessment Tool (BAT), and compared with the existing pressures. Human impacts persist over a number of years and gradually reduce ecosystem health, as discussed in the European Water Framework Directive. Paradoxically, natural events cause stronger impacts but are of a shorter duration, which allows for a faster recovery of macrobenthic communities. The study showed that caution should be taken when developing and implementing water policies so as not to disregard the importance of the different events (natural and human-caused) on the ecosystem health (e.g., community degradation and water quality and ecological quality status assessment).     

Worldwide Typology of Nearshore Coastal Systems: Defining the Estuarine Filter of River Inputs to the Oceans

We present a spatially explicit global overview of nearshore coastal types, based on hydrological, lithological and morphological criteria. A total of four main operational types act as active filters of both dissolved and suspended material entering the ocean from land: small deltas (type I), tidal systems (II), lagoons (III) and fjords (IV). Large rivers (V) largely bypass the nearshore filter, while karstic (VI) and arheic coasts (VII) act as inactive filters. This typology provides new insight into the spatial distribution and inherent heterogeneity of estuarine filters worldwide. The relative importance of each type at the global scale is calculated and types I, II, III and IV account for 32%, 22%, 8% and 26% of the global coastline, respectively, while 12% have a very limited nearshore coastal filter. As an application of this typology, the global estuarine surface area is re-estimated to 1.1 × 10⁶ km² instead of 1.4 × 10⁶ km² in earlier work.