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81.
Understanding the relationship between human disturbance and ecological response is essential to the process of indicator development. For large-scale observational studies, sites should be selected across gradients of anthropogenic stress, but such gradients are often unknown for a population of sites prior to site selection. Stress data available from public sources can be used in a geographic information system (GIS) to partially characterize environmental conditions for large geographic areas without visiting the sites. We divided the U.S. Great Lakes coastal region into 762 units consisting of a shoreline reach and drainage-shed and then summarized over 200 environmental variables in seven categories for the units using a GIS. Redundancy within the categories of environmental variables was reduced using principal components analysis. Environmental strata were generated from cluster analysis using principal component scores as input. To protect against site selection bias, sites were selected in random order from clusters. The site selection process allowed us to exclude sites that were inaccessible and was shown to successfully distribute sites across the range of environmental variation in our GIS data. This design has broad applicability when the goal is to develop ecological indicators using observational data from large-scale surveys.  相似文献   
82.
The Great Basin Desert lies between the Sierra Nevada Mountains to the west and the Rocky Mountains to the east. Nearly 60% of the area’s deserts and mountains (roughly 30 million ha) are managed by the U. S. Department of Interior’s Bureau of Land Management. This area is characterized by low annual precipitation, diverse desert plant communities, and local economies that depend on the products (livestock grazing, recreation, mining, etc.) produced by these lands. The ecological and economic stability of the Great Basin is increasingly at risk due to the expansion of fire-prone invasive species and increase in wildfires. To stem this loss of productivity and diversity in the Great Basin, the BLM initiated the “Great Basin Restoration Initiative” in 1999 after nearly 0.7 million ha of the Great Basin burned in wildfires. The objective of the Great Basin Restoration Initiative is to restore plant community diversity and structure by improving resiliency to disturbance and resistance to invasive species over the long-term. To accomplish this objective, a strategic plan has been developed that emphasizes local participation and reliance on appropriate science to ensure that restoration is accomplished in an economical and ecologically appropriate manner. If restoration in the Great Basin is not successful, desertification and the associated loss of economic stability and ecological integrity will continue to threaten the sustainability of natural resources and people in the Great Basin.  相似文献   
83.
Lake Superior receives inputs from approximately 2,800 tributaries that provide nutrients and dissolved organic matter (DOM) to the nearshore zone of this oligotrophic lake. Here, we review the magnitude and timing of tributary export and plume formation in Lake Superior, how these patterns and interactions may shift with global change, and how emerging technologies can be used to better characterize tributary–lake linkages. Peak tributary export occurs during snowmelt‐driven spring freshets, with additional pulses during rain‐driven storms. Instream processing and transformation of nitrogen, phosphorus, and dissolved organic carbon (DOC) can be rapid but varies seasonally in magnitude. Tributary plumes with elevated DOC concentration, higher turbidity, and distinct DOM character can be detected in the nearshore during times of high runoff, but plumes can be quickly transported and diluted by in‐lake currents and mixing. Understanding the variability in size and load of these tributary plumes, how they are transported within the lake, and how long they persist may be best addressed with environmental sensors and remote sensing using autonomous and unmanned vehicles. The connections between Lake Superior and its tributaries are vulnerable to climate change, and understanding and predicting future changes to these valuable freshwater resources will require a nuanced and detailed consideration of tributary inputs and interactions in time and space.  相似文献   
84.
Managing human use of ecosystems in an era of rapid environmental change requires an understanding of diverse stakeholders’ behaviors and perceptions to enable effective prioritization of actions to mitigate multiple threats. Specifically, research examining how threat perceptions are shared or diverge among stakeholder groups and how these can evolve through time is increasingly important. We investigated environmental threat perceptions related to Australia's Great Barrier Reef and explored their associations before and after consecutive years of mass coral bleaching. We used data from surveys of commercial fishers, tourism operators, and coastal residents (n = 5254) conducted in 2013 and 2017. Threats perceived as most serious differed substantially among groups before bleaching but were strongly aligned after bleaching. Climate change became the most frequently reported threat by all stakeholder groups following the coral bleaching events, and perceptions of fishing and poor water quality as threats also ranked high. Within each of the 3 stakeholder groups, fishers, tourism operators, and coastal residents, the prioritization of these 3 threats tended to diverge in 2013, but convergence occurred after bleaching. These results indicate an emergence of areas of agreement both within and across stakeholder groups. Changes in perceptions were likely influenced by high-profile environmental-disturbance events and media representations of threats. Our results provide insights into the plasticity of environmental-threat perceptions and highlight how their convergence in response to major events may create new opportunities for strategic public engagement and increasing support for management.  相似文献   
85.
Environmental impact assessment (EIA) is identified as an important instrument for facilitating environmental protection and sustainable development. However, since its emergence there has been a growing interest in examining its translation from theory into practice. This paper reviews the translation of mitigation measures proposed in environmental impact statements (EISs) into planning conditions at two platinum mining and processing projects along the Great Dyke of Zimbabwe. By comparing mitigation measures proposed in EISs and those included in environmental management plans (EMPs), examining views of environmental managers and local residents, as well as field observations the mitigation implementation status is verified and evaluated. Results show that 52% of mitigation measures proposed in EISs and mostly procedural are translated into planning conditions. Residents near the platinum processing plant were not satisfied with the mitigation of sulphur dioxide, dust and noise impacts on their health. The need to incorporate and enforce substantive mitigation measures in EISs and planning conditions is recommended for the future.  相似文献   
86.
The Great East Japan Earthquake in March 2011 devastated the eastern region of Japan.Due to the resulting nuclear accident,Japanese Cabinet decided to revise its energy policies.The Energy and Environment Council in National Policy Unit published options on the nation’s scenarios for energy and economy in 2030.We estimated the economic impacts of the options to national economy and households in 2030.Finally,we clarified significant factors to establish a secure,affluent and low-carbon society based on the energy scenarios.  相似文献   
87.
西部大开发中的生态安全问题   总被引:12,自引:0,他引:12       下载免费PDF全文
正确处理区域发展与生态安全是西部开发战略的关键。以可持续发展为目标的区域空间结构理论 ,分析了在新一轮科技革命和产业革命的新形势下推动区域发展和区域空间结构演变的决定性因素 ,以及实行效益原则与社会公平原则相统一的必要性 ,从中引出西部大开发中确保生态安全的极端重要性。并就实现区域发展与生态安全的双赢目标所必须建立的能力体系和制度体系提出了建议。   相似文献   
88.
Abstract:  Ecosystem-scale networks of marine protected areas (MPAs) are important conservation tools, but their effectiveness is difficult to quantify in a time frame appropriate to species conservation because of uncertainties in the data available. The dugong ( Dugong dugon ) is a mobile marine species that occurs in shallow inshore waters of an ecosystem-scale network of MPAs (the Great Barrier Reef World Heritage Area [GBRWHA]). We developed a rapid approach to assess risk to dugongs in the region and evaluate options to ameliorate that risk. We used expert opinion and a Delphi technique to identify and rank 5 human factors with the potential to adversely affect dugongs and their sea grass habitats: netting, indigenous hunting, trawling, vessel traffic, and poor-quality terrestrial runoff. We then quantified and compared the distribution of these factors with a spatially explicit model of dugong distribution. We estimated that approximately 96% of habitat of high conservation value for dugongs in the GBRWHA is at low risk from human activities. Using a sensitivity analysis, we found that to decrease risk, commercial netting or indigenous hunting had to be reduced in remote areas and the effects of vessel traffic, terrestrial runoff, and commercial netting had to be reduced in urban areas. This approach enabled us to compare and rank risks so as to identify the most severe risks and locate specific sites that require further management attention.  相似文献   
89.
ABSTRACT: The flood hydroclimatology of the Grand Forks flood of April 1997, the most costly flood on a per capita basis for a major metropolitan area in United States history, is analyzed in terms of the natural processes that control spring snowmelt flooding in the region. The geomorphological characteristics of the basin are reviewed, and an integrated assessment of the hydroclimatological conditions during the winter of 1996 to 1997 is presented to gain a real‐world understanding of the physical basis of this catastrophic flood event. The Grand Forks flood resulted from the principal flood‐producing factors occurring at either historic or extreme levels, or at levels conducive to severe flooding. Above normal fall precipitation increased the fall soil moisture storage and reduced the spring soil moisture storage potential. A concrete frost layer developed that effectively reduced the soil infiltration capacity to zero. Record snowfall totals and snow cover depths occurred across the basin because of the unusual persistence of a blocking high circulation pattern throughout the winter. A severe, late spring blizzard delayed the snowmelt season and replenished the snow cover to record levels for early April. This blizzard was followed by a sudden transition to an extreme late season thaw due to the abrupt breakdown of the blocking circulation pattern. The presence of river ice contributed to backwater effects and affected the timing of tributary inflows to the main stem of the Red River. Only the absence of spring rains prevented an even more catastrophic flood disaster from taking place. This paper contributes to our understanding of the flood hydroclimatology of catastrophic flood events in an unusual flood hazard region that possesses relatively flat terrain, a north‐flowing river, and an annual peak discharge time series dominated by spring snowmelt floods.  相似文献   
90.
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