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1.
Seyedeh Belin Tavakoly Sany Mohammad Tajfard Rosli Hashim Majid Rezayi Mohammad Azizur Rahman David J. Karlen 《Estuaries and Coasts》2018,41(4):1178-1192
The relative contributions of spatial and temporal fluctuations are different in shaping natural communities in a tropical coastal/estuarine system. Understanding how coastal communities respond to these fluctuations is still equivocal, and thus, available data are rare. Here, multiple analytical approaches were used to identify key spatial and temporal factors, and to quantify their relative roles in shaping a macrobenthic community through space (contamination degree, physical parameters, and sediment characteristics) and time (climatic factors, season, and year). A dataset of eight sampling times was analyzed over a period of 2 years, in which macrobenthic species abundances were sampled. A total of 33 species were identified, including 18 bivalves, 5 gastropods, and 4 crustaceans. The other taxa were less diverse. The results show that there were no significant temporal changes of macrobenthic community structure, but spatial changes were significant and synchronized with environmental factors (i.e., sediment characteristics, water depth, and the distance from anthropogenic sources). This study demonstrates that spatial factors played a primary role in structuring of macrobenthic assemblages, whereas the influence of temporal factors appeared less across geographically distinct sites. Thus, temporal variation of a coastal macrobenthic community appears to be controlled by partly different processes at different scales. 相似文献
2.
The effects of low dissolved oxygen or hypoxia (<2 mg l?1) on macrobenthic infaunal community structure and composition in the lower Chesapeake Bay and its major tributaries, the Rappahannock, York, and James rivers are reported. Macrobenthic communities at hypoxia-affected stations were characterized by lower species diversity, lower biomass, a lower proportion of deep-dwelling biomass (deeper than 5 cm in the sediment), and changes in community composition. Higher dominance in density and biomass of opportunistic species (e.g., euryhaline annelids) and lower dominance of equilibrium species (e.g., long-lived bivalves and maldanid polychaetes) were observed at hypoxia-affected stations. Hypoxia-affected macrobenthic communities were found in the polyhaline deep western channel of the bay mainstem north of the Rappahannock River and in the mesohaline region of the lower Rappahannock River. No hypoxic effects on the infaunal macrobenthos were found in the York River, James River, or other deep-water channels of the lower Chesapeake Bay. 相似文献
3.
D. Sanger A. Blair G. DiDonato T. Washburn S. Jones G. Riekerk E. Wirth J. Stewart D. White L. Vandiver A. F. Holland 《Estuaries and Coasts》2015,38(1):49-66
Upland areas of southeastern United States tidal creek watersheds are popular locations for development, and they form part of the estuarine ecosystem characterized by high economic and ecological value. The primary objective of this work was to define the relationships between coastal development, with its concomitant land use changes and associated increases in nonpoint source pollution loading, and the ecological condition of tidal creek ecosystems including related consequences to human populations and coastal communities. Nineteen tidal creek systems, located along the southeastern US coast from southern North Carolina to southern Georgia, were sampled in the summer, 2005 and 2006. Within each system, creeks were divided into two primary segments based upon tidal zoning—intertidal (i.e., shallow, narrow headwater sections) and subtidal (i.e., deeper and wider sections)—and then watersheds were delineated for each segment. Relationships between coastal development, concomitant land use changes, nonpoint source pollution loading, the ecological condition of tidal creek ecosystems, and the potential impacts to human populations and coastal communities were evaluated. In particular, relationships were identified between the amount of impervious cover (indicator of coastal development) and a range of exposure and response measures including increased chemical contamination of the sediments, increased pathogens in the water, increased nitrate/nitrite levels, increased salinity range, decreased biological productivity of the macrobenthos, alterations to the food web, increased flooding potential, and increased human risk of exposure to pathogens and harmful chemicals. The integrity of tidal creeks, particularly the headwaters or intertidally dominated sections, was impaired by increases in nonpoint source pollution associated with sprawling urbanization (i.e., increases in impervious cover). This finding suggests that these habitats are valuable early warning sentinels of ensuing ecological impacts and potential public health and flooding risk from sprawling coastal development. The results also validate the use of a conceptual model with impervious cover thresholds for tidal creek systems in the southeast region. 相似文献
4.
Three quarters of the global human population will live in coastal areas in the coming decades and will continue to develop these areas as population density increases. Anthropogenic stressors from this coastal development may lead to fragmented habitats, altered food webs, changes in sediment characteristics, and loss of near-shore vegetated habitats. Seagrass systems are important vegetated estuarine habitats that are vulnerable to anthropogenic stressors, but provide valuable ecosystem functions. Key to maintaining these habitats that filter water, stabilize sediments, and provide refuge to juvenile animals is an understanding of the impacts of local coastal development. To assess development impacts in seagrass communities, we surveyed 20 seagrass beds in lower Chesapeake Bay, VA. We sampled primary producers, consumers, water quality, and sediment characteristics in seagrass beds, and characterized development along the adjacent shoreline using land cover data. Overall, we could not detect effects of local coastal development on these seagrass communities. Seagrass biomass varied only between sites, and was positively correlated with sediment organic matter. Epiphytic algal biomass and epibiont (epifauna and epiphyte) community composition varied between western and eastern regions of the bay. But, neither eelgrass (Zostera marina) leaf nitrogen (a proxy for integrated nitrogen loading), crustacean grazer biomass, epifaunal predator abundance, nor fish and crab abundance differed significantly among sites or regions. Overall, factors operating on different scales appear to drive primary producers, seagrass-associated faunal communities, and sediment properties in these important submerged vegetated habitats in lower Chesapeake Bay. 相似文献
5.
The scientific community is confident that warming of the Earth’s climate is unequivocal. Sea-level rise, which poses potential threats to coastal areas, is one of the most recognised possible impacts of this climate change. The nonlinearities, complexities, and spatial and temporal lags are common characteristics of coastal processes driven by human and natural interaction. With the acknowledgement of the complexity and dynamic nature of coastal systems, this paper introduces a spatial–temporal assessment framework, for addressing both the temporal and spatial variations, when assessing the vulnerability of natural and human systems in coastal areas. The framework is based upon a combination of system dynamics (SD) modelling and geographical information systems by taking into account spatial (x, y, z) and temporal (t) dimensions. The strategy of the adopted approach is to use the loose coupling approach by which a spatial model component is incorporated into a SD model component through a data converter. 相似文献
6.
Anthropogenic global climate change is anticipated to increase the frequency and intensity of transient extreme weather events that can be catastrophic to ecological communities. Here, we characterize an extremely stressful, transient phenomenon on southeastern Mediterranean (Israel) rocky shores: prolonged desiccation events (PDE). We also examined (during 2012–2014) its potential ecological impacts on the unique intertidal Mediterranean Sea ecosystem—vermetid reefs. In this region, where the tide is minimal but the rocky intertidal is extensive, high pressure and dry easterly winds generated by specific synoptic systems can suppress tidal flooding and create stressful desiccation conditions in the lower intertidal zones for many consecutive days (several days to weeks). Very long and strong PDEs resulted in extensive macroalgal bleaching and their eventual removal from the rocks and caused mortality of stranded topshell snails and partial collapse of the mid-shore limpet population. Dominant intertidal fleshy algae were shown to be more sensitive than calcareous algae to desiccation stress, but both die after 24 h of exposure in lab conditions. Re-analysis of climatic data for the period 1960–2010 showed a considerable increase in the frequency of PDE-generating synoptic systems, mainly during winter. This means that desiccation stress has already increased on southeastern Mediterranean vermetid reef ecological communities, and if this trend continues, we can expect further increases in aerial exposure and desiccation stress that could have long-term impacts on this fragile ecosystem. These results demonstrate the importance of change in patterns of synoptic systems and wind regimes to the integrity of coastal ecological communities. 相似文献
7.
As the largest ecosystems of the earth, marine ecosystem provides many types of ecosystem service to human. More than 60% of the global population lives the coastal area. A healthy ocean is critical to our economy, health and way of life. However, with rapid population growth and densely inhabited coastal areas, our dependence on marine resources is greater than ever. The overuse and mismanagement of ecosystem services have placed great pressure on marine systems, thereby threatening the future of marine ecosystems, and the services they provide. With anthropogenic pressures increasing in coastal cities, adopting ecosystem-based management frameworks that minimize impacts on marine environments while allowing for sustainable development is critical. Marine Ecosystem-Based Management seeks to manage marine resources in ways that protect ecosystem health while providing the ecosystem services needed by people. Rather than focusing solely on a single species or resource, MEBM incorporates science and balances the demands of user groups in a manner that produces management strategies that are more likely to be sustainable than traditional approaches. The definition, principles and framework were discussed in this paper based on the summary of literature, and two examples were introduced. Last, some suggestions were put forward to marine ecosystem management for ocean ecosystem and for healthy coastal resources sustainable utilization. 相似文献
8.
The changing number and nature of weather- and climate-related natural hazards is causing more communities to need to assess their vulnerabilities. Vulnerability assessments, however, often require considerable expertise and resources that are not available or too expensive for many communities. To meet the need for an easy-to-use, cost-effective vulnerability assessment tool for communities, a prototype online vulnerability assessment support system was built and tested. This prototype tool guides users through a stakeholder-based vulnerability assessment that breaks the process into four easy-to-implement steps. Data sources are integrated in the online environment so that perceived risks??defined and prioritized qualitatively by users??can be compared and discussed against the impacts that past events have had on the community. The support system is limited in scope, and the locations of the case studies do not provide a sufficiently broad range of sample cases. The addition of more publically available hazard databases combined with future improvements in the support system architecture and software will expand opportunities for testing and fully implementing the support system. 相似文献
9.
The present study investigated the macrobenthic community in Tolo Harbour, Hong Kong, aiming at linking heavy metal concentrations
to differences in macrobenthic community. The stations investigated in Tolo Harbour have widely contrasting features, with
some areas located in the Plove Cove displaying both high species richness and abundance while other areas displaying quite
impoverished or even void of macrobenthos. High diversity and abundance of macrobenthos in areas with low heavy metal concentrations
were recorded. Strong negative correlation between macrobenthic diversity and heavy metal concentrations was found, and this
implicated the pollution-induced degradation of macrobenthos in some locations in Tolo Harbour. These results support the
Pearson–Rosenberg model for succession along a pollution gradient. 相似文献
10.
Concern for natural hazard-triggered technological disasters (Natech disasters) in densely populated and industrialized areas
is growing. Residents living in urban areas subject to high natural hazard risk are often unaware of the potential for secondary
disasters such as hazardous materials releases from neighboring industrial facilities, chemical storage warehouses or other
establishments housing hazardous materials. Lessons from previous disasters, such as the Natech disaster during the Kocaeli
earthquake in Turkey in 1999 call for the need to manage low frequency/high consequence events, particularly in today’s densely
populated areas. However, there is little guidance available on how local governments and communities can assess Natech risk.
To add to the problem, local governments often do not have the human or economic resources or expertise to carry out detailed
risk assessments. In this article, we propose a methodology for preliminary assessment of Natech risk in urban areas. The
proposed methodology is intended for use by local government officials in consultation with the public. The methodology considers
possible interactions between the various systems in the urban environment: the physical infrastructure (e.g., industrial
plants, lifeline systems, critical facilities), the community (e.g., population exposed), the natural environment (e.g., delicate
ecosystems, river basins), and the risk and emergency management systems (e.g., structural and nonstructural measures). Factors
related to vulnerability and hazard are analyzed and qualitative measures are recommended. Data from hazardous materials releases
during the Kocaeli, Turkey earthquake of August 17, 1999 are used as a case study to demonstrate the applicability of the
methodology. Limitations of the proposed methodology are discussed as well as future research needs.
相似文献
| Norio OkadaEmail: |
11.
Angeliki Mentzafou Chrysa Vamvakaki Ierotheos Zacharias Areti Gianni Elias Dimitriou 《Environmental Earth Sciences》2017,76(6):259
The Spercheios river basin—coastal marine area is a complex natural and interdependent ecosystem, highly affected by human activities and interventions. Such sensitive systems are even more vulnerable to alterations of the hydrological cycle components and it is likely to be rapidly and severely affected by climate change. In order to examine the climate change impacts on water resources of the study area, the interaction between the hydrology of the river basin and the hydrodynamic of the coastal marine area was examined using two models. Based on the results, although the irrigation needs decrease for the years 2050 and 2100 due to corresponding decrease in cultivated areas, temperature increase and precipitation decrease are both expected to influence the water resources of the Spercheios river basin, which will directly affect the Maliakos Gulf hydrodynamics. The necessity to adopt a holistic approach which will treat river basins and coastal marine areas as an integrated whole, with regard to environmental, socio-economic and political framework, is evident. 相似文献
12.
Diane U. Keogh Armando Apan Shahbaz Mushtaq David King Melanie Thomas 《Natural Hazards》2011,59(2):699-723
Australia is currently experiencing climate change effects in the form of higher temperatures and more frequent extreme events,
such as floods. Floods are its costliest form of natural disaster accounting for losses estimated at over $300 million per
annum. This article presents an historical case study of climate adaptation of an Australian town that is subject to frequent
flooding. Charleville is a small, inland rural town in Queensland situated on an extensive flood plain, with no significant
elevated areas available for relocation. The study aimed to gain an understanding of the vulnerability, resilience and adaptive
capacity of this community by studying the 2008 flood event. Structured questionnaires were administered in personal interviews
in February 2010 to householders and businesses affected by the 2008 flood, and to institutional personnel servicing the region
(n = 91). Data were analysed using appropriate quantitative and qualitative techniques. Charleville was found to be staunchly
resilient, with high levels of organisation and cooperation, and well-developed and functioning social and institutional networks.
The community is committed to remaining in the town despite the prospect of continued future flooding. Its main vulnerabilities
included low levels of insurance cover (32% residents, 43% businesses had cover) and limited monitoring data to warn of impending
flooding. Detailed flood modelling and additional river height gauging stations are needed to enable more targeted evacuations.
Further mitigation works (e.g., investigate desilting Bradley’s Gully and carry out an engineering assessment) and more affordable
insurance products are needed. Regular information on how residents can prepare for floods and the roles different organisations
play are suggested. A key finding was that residents believe they have a personal responsibility for preparation and personal
mitigation activities, and these activities contribute substantially to Charleville’s ability to respond to and cope with
flood events. More research into the psychological impacts of floods is recommended. Charleville is a valuable representation
of climate change adaptation and how communities facing natural disasters should organise and operate. 相似文献
13.
We studied changes in macrobenthic communities following the environmental clean-up of metal-polluted (cadmium, nickel, and
cobalt) sediments in Foundry Cove, a small inlet within the Hudson River estuary of New York. We used a BACI-style experiment
to test the hypotheses that high levels of cadmium in sediments change macrobenthic assemblages relative to unpolluted areas,
and removal of metals (especially cadmium) by dredging will restore the benthos, such that benthic fauna in Foundry Cove are
not different from unpolluted areas. In 1984, prior to the restoration work, there were no significant differneces between
macrobenthic assemblages in polluted and unpolluted locations, indicating that cadmium had little effect on community structure.
The lack of an observed toxicity effect may have been caused by the compensatory evolution of resistance to cadmium in dominant
organisms. Six years after the restoration work and despite a substantial reduction in metal pollution, there were lower abundances
of oligochaetes, nematodes, and chironomids and a higher abundance of polychaetes at Foundry Cove relative to reference locations.
Correlative analyses identified greater sediment compaction caused by dredging at Foundry, Cove as a possible cause of faunal
differences. The results demonstrate that it is difficult to accurately predict, the effects of anthropogenic disturbances
and restorations in complex natural systems and that unforeseen side effects are inevitable. Documenting these unpredicted
effects and experimentally understanding their causes in past restorations will greatly improve the success and cost-effectiveness
of future projects of a similar type. 相似文献
14.
黄河三角洲滨海湿地健康条件评价概念模型 总被引：3，自引：0，他引：3
滨海湿地健康与生物学特征主要取决于区域上的水文与盐度体制以及景观尺度上的土地利用现状。然而,由于滨海湿地条件评价的指标和标准并不十分清楚,因此,对滨海湿地系统条件进行评价,目前仍是环境科学的难点。中国地质调查局（CGS）青岛海洋地质研究所与美国地质调查局湿地研究中心合作先后为美国密西西比河下游生态环境及中国黄河三角洲（YRD）滨海湿地评价建立了概念模型。本文将陈述YRD湿地评价的概念模型。此模型的建立在于确定滨海湿地当前的条件和随时间改善或退化的过程,以及确定优先管理的区域。CGS项目之所以选取YRD作为滨海湿地的研究对象主要是因为它具有重要的生态意义。由于上游来水减少或黄河断流,该区湿地生境十分脆弱。本文提出此概念模型可为今后湿地条件评价指标确定、调查研究活动和数据采集提供指导。通过该模型的构建,使环境变化可用具体指标来度量,从而服务于滨海湿地生态系统的保护与管理活动。 相似文献
15.
Villagra Paula Herrmann Marie Geraldine Quintana Carolina Sepúlveda Roger D. 《Natural Hazards》2017,88(2):1087-1111
Tsunamic events are a frequent hazard to coastal towns. Despite this, the extent to which resilience models can be applied to coastal towns as well as the aspects that should be considered when doing so have not been fully evaluated. There is little information regarding the specific indicators that allow cities to better cope and adapt to the impacts of tsunamis, and this information is especially scarce for developing countries such as Chile. The main objective of this study is to develop a resilience model to explore the extent to which local characteristics influence the resilience of Chilean coastal communities to tsunami hazards. Accordingly, this study presents the Coastal Community Resilience model (The CORE model) for exploring the adaptive capacity of coastal areas affected by tsunamis. This model was then applied to fourteen coastal villages, distributed within four towns, three communes, and two regions of Chile. Data comprising 21 indicators that address the physical, environmental, and social resilience aspects of the villages were obtained on-site and from governmental and municipality databases; these data were then subjected to multivariate analysis in order to determine which indicators most and least affect resilience and whether indicators affect resilience positively or negatively. Variation in resilience among the villages was explained by similarities and differences in the administrative-political, urban, rural, and indigenous characteristics of the study areas. In addition to these results, we discuss land use planning considerations to build community resilience, and we provide insight into the utility of the resilience model proposed here. Overall, our findings shed light on gaps in planning policies and opportunities for planning coastal resilient communities, particularly for those where data of explicit indicators are scarce like in Chile and other developing countries.
相似文献16.
PROBLEM STATEMENT: In a simple economic model, water scarcity arises as a result of an imbalance between the supply of and demand for water sources. Distribution in this setting is the source of numerous conflicts globally. APPROACH: Already, the Southwestern United States (US) suffers from annual drought and long-standing feud over natural water resources. RESULTS: Population growth in the Southwestern United States along with the continued effects of climate change (natural and anthropogenic) predicts a perpetual decline in natural water sources, such as smaller snowpacks, in the coming years. As the increasing number of communities across multiple US states that subsist off of natural water supplies face water shortages with increasing severity, further water conflict will emerge. Such conflicts become especially protracted when the diversion of water from a source of benefit to one community negatively impacts nearby communities of humans and economically vital ecosystems (e.g., marshlands or tributaries). CONCLUSION/RECOMMENDATIONS: The ensuing politics and health effects of these diversions can be complicated and future water policies both domestically and internationally are lacking. To draw attention to and stimulate discussion around the lacking policy discussion domestically, herein we document existing and emerging consequences of watery scarcity in the Southwestern United States and briefly outline past and potential future policy responses. 相似文献
17.
Ronald T. Eguchi 《Natural Hazards》2013,68(1):201-202
Disaster experts around the world have continually warned governments and the public about the possibility of “worst-case” natural hazard scenarios and their overwhelming impacts. Yet, planning for the occurrence of these events has fallen far short of need. The large earthquake that occurred off the coast of Sumatra in 2004, which resulted in one of the deadliest tsunamis ever recorded, was a painful reminder that living in some of the most desirable areas of the world does have its risks. We all have enjoyed the fun of restful visits to coastal resort communities all around the world, and we rarely think about earthquakes or tsunamis interfering with this enjoyment. Yet, they take us by surprise. Before these events do occur, there should be adequate education for everyone on what actions are appropriate as well as an effective warning system to trigger the right actions. 相似文献
18.
Zhu Chonghao Zhang Jianjing Liu Yang Ma Donghua Li Mengfang Xiang Bo 《Natural Hazards》2020,101(1):173-194
Communities everywhere are being subjected to a variety of natural hazard events that can result in significant disruption to critical functions. As a result, community resilience assessment in these locations is gaining popularity as a means to help better prepare for, respond to, and recover from potentially disruptive events. The objective of this study was to identify key vulnerabilities relevant to addressing rural community resilience through conducting an initial flood impact analysis, with a specific focus on emergency response and transportation network accessibility. It included a use case involving the flooding of a rural community along the US inland waterway system. Special consideration was given to impacts experienced by at-risk populations (e.g., low economic status, youth, and elderly), given their unique vulnerabilities. An important backdrop to this work is recognition that Federal Emergency Management Agency’s Hazus, a free, publicly available tool, is commonly recommended by the agency for counties, particularly those with limited resources (i.e., rural areas), to use in developing their hazard mitigation plans. The case study results, however, demonstrate that Hazus, as currently utilized, has some serious deficiencies in that it: (1) likely underestimates the flood extent boundaries for study regions in a Level 1 analysis (which solely relies upon filling digital elevation models with precipitation), (2) may be incorrectly predicting the number and location of damaged buildings due to its reliance on out-of-date census data and the assumption that buildings are evenly distributed within a census block, and (3) is incomplete in its reporting of the accessibility of socially vulnerable populations and response capabilities of essential facilities. Therefore, if counties base their flood emergency response plans solely on Hazus results, they are likely to be underprepared for future flood events of significant magnitude. An approach in which Hazus results can be augmented with additional data and analyses is proposed to provide a more risk-informed assessment of community-level flood resilience.
相似文献19.
The importance of the El Niño-Southern Oscillation (ENSO) on regional-scale climate variability is well recognized although the associated effects on local weather patterns are poorly understood. Little work has addressed the ancillary impacts of climate variability at the community level, which require analysis at a local scale. In coastal communities water quality and public health effects are of particular interest. Here we describe the historical influence of ENSO events on coastal water quality in Tampa Bay, Florida (USA) as a test case. Using approximate randomized statistics, we show significant ENSO influences on water quality particularly during winter months, with significantly greater fecal pollution levels during strong El Niño winters and significantly lower levels during strong La Niña winters as compared to neutral conditions. Similar significant patterns were also noted for El Niño and La Niña fall periods. The success of the analysis demonstrates the feasibility of assessing local effects associated with large-scale climate variability. It also highlights the possibility of using ENSO forecasts to predict periods of poor coastal water quality in urban region which local agencies may use to make appropriate prepations. 相似文献
20.
Assessing future risk: quantifying the effects of sea level rise on storm surge risk for the southern shores of Long Island, New York 总被引：2，自引：1，他引：1
Christine C. Shepard Vera N. Agostini Ben Gilmer Tashya Allen Jeff Stone William Brooks Michael W. Beck 《Natural Hazards》2012,60(2):727-745
Sea level rise threatens to increase the impacts of future storms and hurricanes on coastal communities. However, many coastal
hazard mitigation plans do not consider sea level rise when assessing storm surge risk. Here we apply a GIS-based approach
to quantify potential changes in storm surge risk due to sea level rise on Long Island, New York. We demonstrate a method
for combining hazard exposure and community vulnerability to spatially characterize risk for both present and future sea level
conditions using commonly available national data sets. Our results show that sea level rise will likely increase risk in
many coastal areas and will potentially create risk where it was not before. We find that even modest and probable sea level
rise (.5 m by 2080) vastly increases the numbers of people (47% increase) and property loss (73% increase) impacted by storm
surge. In addition, the resulting maps of hazard exposure and community vulnerability provide a clear and useful example of
the visual representation of the spatial distribution of the components of risk that can be helpful for developing targeted
hazard mitigation and climate change adaptation strategies. Our results suggest that coastal agencies tasked with managing
storm surge risk must consider the effects of sea level rise if they are to ensure safe and sustainable coastal communities
in the future. 相似文献