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141.
Departing from a theoretical methodology, we estimate empirically an index of adaptive capacity (IAC) of a fishing community to the establishment of marine protected areas (MPAs). We carried out household surveys, designed to obtain information for indicators and sub-indicators, and calculated the IAC. Moreover, we performed a sensitivity analysis to check for robustness of the results. Our findings show that, despite being located between two MPAs, the fishing community of Bazán in the Colombian Pacific is highly vulnerable and that the socioeconomic dimension of the IAC constitutes the most binding dimension for building adaptive capacity. Bazán is characterized by extreme poverty, high dependence on resources, and lack of basic public infrastructure. Notwithstanding, social capital and local awareness about ecological conditions may act as enhancers of adaptive capacity. The establishment of MPAs should consider the development of strategies to confer adaptive capacity to local communities highly dependent on resource extraction.  相似文献   
142.
使用电感耦合等离子体质谱仪,对东海及冲绳海槽沉积物、南海及邻近海域以及西北太平洋表层水中240Pu/239Pu同位素比值进行了测定,以确定中国领海核爆散落核素钚的主要来源及迁移途径。结果显示:东海及冲绳海槽沉积物中240Pu/239Pu比值分布于0.24~0.31之间,南海及邻近海域以及西北太平洋表层水240Pu/239Pu比值也处于0.22~0.24之间,都明显高于全球大气理论沉降值0.18。根据240Pu/239Pu比值及其在沉积物芯中的分布特征分析,二十世纪50年代早期美国在北太平洋马绍尔群岛进行的核爆实验,被认为是中国领海及其邻近海域除全球大气沉降外的另一重要的钚的来源。模式计算显示,东海及冲绳沉积物中约55%、中国南海及其邻近海域表层水中约40%、西北太平洋表层水中约20%的钚,来自北太平洋核爆基地。北太平洋赤道环流及其在西北太平洋的分支洋流是钚自核爆地向中国领海迁移的主要通道。  相似文献   
143.
Abstract: Since the 1940s, snow water equivalent (SWE) has decreased throughout the Pacific Northwest, while water use has increased. Climate has been proposed as the primary cause of base‐flow decline in the Scott River, an important coho salmon rearing tributary in the Klamath Basin. We took a comparative‐basin approach to estimating the relative contributions of climatic and non‐climatic factors to this decline. We used permutation tests to compare discharge in 5 streams and 16 snow courses between “historic” (1942‐1976) and “modern” (1977‐2005) time periods, defined by cool and warm phases, respectively, of the Pacific Decadal Oscillation. April 1 SWE decreased significantly at most snow courses lower than 1,800 m in elevation and increased slightly at higher elevations. Correspondingly, base flow decreased significantly in the two streams with the lowest latitude‐adjusted elevation and increased slightly in two higher‐elevation streams. Base‐flow decline in the Scott River, the only study stream heavily utilized for irrigation, was larger than that in all other streams and larger than predicted by elevation. Based on comparison with a neighboring stream draining wilderness, we estimate that 39% of the observed 10 Mm3 decline in July 1‐October 22 discharge in the Scott River is explained by regional‐scale climatic factors. The remainder of the decline is attributable to local factors, which include an increase in irrigation withdrawal from 48 to 103 Mm3/year since the 1950s.  相似文献   
144.
ABSTRACT: The hypotheses that fish survival probabilities may be lower (1) at less than peak operating turbine efficiency; (2) at deeper entrainment depth; and (3) with the deployment of extended‐length intake guidance screens, are not supported by results on yearling chinook salmon smolts (Oncorhynchus tshawytscha) at Lower Granite Dam, Snake River, Washington. Estimated 96 h survival probabilities for the six test conditions ranged from 0.937 to 0.972, with the highest survival at turbine operating towards the lower end of its efficiency. A blanket recommendation to operate all Kaplan type turbines within ± 1 percent of their peak efficiency appears too restrictive. Cavitation mode survival (0.946) was comparable to that at peak operating efficiency mode (0.937), as was the survival between upper (0.947) and mid depths (0.937). Survival differed only slightly among three turbine intake bays at the same depth (0.937 to 0.954), most likely due to differential flow distribution. Extended‐length intake fish guidance screens did not reduce survival. However, the sources of injury somewhat differed with depth; probable pressure and shear‐related injuries were common on fish entrained at mid‐depth, and mechanically‐induced injuries were common at upper depth. Operating conditions that reduce turbulence within the turbine environment may enhance fish survival; however, controlled experiments that integrate turbine flow physics and geometry and the path entrained fish traverse are needed to develop specific guidance to further enhance fish passage survival.  相似文献   
145.
Sustainability is achieved only when there is full reconciliation between: (1) economic development; (2) meeting, on an equitable basis, growing and changing human needs and aspirations; and (3) conserving the limited natural resources and the capacity of the environment to absorb the mulitple stresses that are a consequence of human activities. The linkages between climate and sustainability are examined in the context of both the wider Asia-Pacific region and local level climate risks and adaptation responses. These findings are used to underpin and illustrate several implications for sustainability science. Climate change is seen as both an impediment to increasing sustainability and as an opportunity, though in most cases the former far outweighs the latter. Assessments of climate change vulnerability and risk are shown to be of critical importance because they inform decisions as to where resources for adaptation are best invested. They also show whether global efforts to reduce greenhouse gas emissions need to be strengthened because of limits to adaptation. In practice, adaptation takes place at many levels, essentially ranging between tangible interventions at community and enterprise level and national and international efforts to strengthen the enabling environment for adaptation. It is informative to undertake regional assessments of adaptation, even though most adaptation interventions need to reflect local conditions, including local adaptive capacities. The foregoing findings, based in part on a series of regional and local case studies, lead to several recommendations for further research that will help reduce barriers to implementing responses that reduce climate related risks, including adverse consequences for sustainability. The recommendations relate to such themes as making optimum use of predictive capabilities, characterising the linkages between climate change and sustainability, implications of the required rates and magnitudes of adaptation, institutional responses that enhance adaptive capacity, use of new and traditional technologies, the multiple dimensions of social responsibility, and enhancing the enabling environment for adaptation at the community and enterprise level. If these recommendations are acted upon they will, in turn, help address much needed improvements in quantifying the costs and benefits of adaptation, prioritising adaptation options, assessing sustainable development tradeoffs, and monitoring the success of adaptation initiatives. Such improvements will have even greater utility if they are incorporated into user-friendly decision support tools for adaptation.  相似文献   
146.
A 30 x 0.9 cm piece of steel rod bent in the shape of an “L” and attached by hose clamps to a 15 x 3.2 cm section of plastic pipe sliding on an 86 x 1.9 cm steel shaft was tested for use in measuring scour and fill of salmon spawning riffles. Installed along channel cross-sections, results of tests at four sites on two hydraulically different streams showed the device to be useful in monitoring event specific scour and fill. Measurement error was estimated to be ± 10 mm.  相似文献   
147.
ABSTRACT: This paper draws on interviews with Washington State Watershed Planning Leads (Planning Leads) and interactions with local watershed planning units to identify factors that may influence the inclusion of climate change in watershed planning efforts in Washington State. These factors include the interest of individual planning unit members in climate change; Planning Lead familiarity with climate impacts; the influence of trust, leadership, and “genetic knowledge” on planning units; and perceptions of strategic gain. The research also identifies aspects of the planning process that may create opportunities for addressing climate impacts in future planning. These aspects include continuation of watershed planning units after plans are developed; commitment to updating watershed plans; recognition of climate impacts in planning documentation; dedicated incentive funding; and the availability of hydrologic modeling tools for assessing hydrologic impacts. Additional types of technical assistance that could support integration of climate impacts are also identified. It is hoped that the insight provided by this analysis will help individuals involved in stakeholder‐based watershed planning recognize the various dynamics potentially affecting the inclusion of climate change in watershed planning and in doing so, contribute to the development of planning approaches and tools that will support local efforts to adapt to climate impacts.  相似文献   
148.
江苏省春季连阴雨和太平洋海温的响应关系研究   总被引:1,自引:0,他引:1  
对太平洋海温和江苏省春季连阴雨进行相关普查,通过非线性最优化因子处理方法对太平洋海温因子进行变换,确定高相关区。结果表明:江苏春季连阴雨的发生与太平洋海温的变化显著相关,从相关区域的大小看,下半年各海区温度变化与江苏次年春季连阴雨的相互关系更为密切,苏南和江淮地区的显著性要优于淮北;而从海区的位置上看,淮北连阴雨的相关海区在冬春季主要集中在高纬地区,夏季在低纬地区;其它地区的相关海区则从春季开始由高纬度向低纬度地区过渡。通过t检验分析了ENSO现象对当年和次年的江苏省春季连阴雨发生的次数的影响,发现EI Nino事件对当年和次年的江苏春季连阴雨发生次数均呈正效应,La Nina事件对当年江苏春季连阴雨无显著影响,与次年的春季连阴雨呈负效应。  相似文献   
149.
ABSTRACT: While much is known about the hydrology of forested mountain catchments in the Pacific Northwest, important research questions remain. For example, the dynamics of storm precipitation amounts and the modeling of catchment outflows represent a continuing research need. Without an improved understanding of the spatial and temporal aspects of storm precipitation patterns, our ability to evaluate and improve physically-based hydrologic models is limited. From a practical perspective, tens of thousands of kilometers of access roads have been constructed across forested catchments of the Pacific Northwest. Yet, few forestry research programs focus on road drainage (e.g., ditches, culverts, fords). The few studies that address this issue indicate road drainage systems need to function effectively over a wide range of flow events and terrain conditions. In addition, historical forest practices associated with hillslopes and riparian systems have altered the character of many Pacific Northwest aquatic ecosystems. If restoration of these systems is to be effective, research efforts are needed to better understand the linkages between riparian forests, geomorphic processes, and hydrologic disturbance regimes.  相似文献   
150.
《Environmental Hazards》2013,12(3):210-223
Traditional knowledge of disasters has been found to save lives. On remote islands where telecommunications to the mainland are unreliable, unless there are always working batteries in the radio, signs from the environment may be the only warning of an oncoming cyclone. But this knowledge is in danger of being lost, as it is an oral history not well documented, and younger people increasingly rely on technology. This article presents the results of fieldwork on remote islands in Fiji and Tonga in the South Pacific, documenting natural warning signs on islands in two different countries. The results show that there are numerous known signs, with remarkable similarities and consistencies between the two islands. This provides evidence that not only is traditional knowledge of warning signs for cyclones alive and well, the consistency in the signs suggests support for this knowledge as being just as important as western scientific knowledge. The integration of traditional knowledge and western scientific knowledge into a comprehensive warning system may help to overcome some of the limitations of the existing system and the reasons why warnings are sometimes ignored.  相似文献   
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