Application of participatory principles to investigation of the natural world: An example from Chile     

Sarah Schumann 《Marine Policy》2010

Participatory research in environmental and natural resources-related fields is premised on many of the same notions that underlie participatory processes in decision making. This study examines one instance of participatory research to assess the extent to which the documented benefits of participatory decision-making hold up in the context of research. A survey of Chilean shell-fishers engaged in research with marine biologists assesses the relationships between four variables: fishers’ participation in research, fishers’ opinions of biologists, fishers’ trust in biologists, and fishers’ acquisition of knowledge from biologists. Results illuminate the multidimensionality of these variables and suggest that complex interrelationships between them make the benefits of participatory research more nuanced than those reported for participatory decision-making. For instance, participatory research may provide low benefits when participatory research outcomes differ little from those produced solely by scientists. In addition, high-cost scenarios may result when outcomes of participatory research are inferior to those produced solely by scientists. A third downside may result when participation leads participants to increase their deference to scientific knowledge, thereby defeating the corroborative purpose of their participation. A fourth effect may occur when increased trust by in scientists results from participation, decreasing participants’ perceived need to take part in research.  相似文献   

Experimental and numerical investigation of local scour around a submerged vertical circular cylinder in steady currents   总被引：1，自引：0，他引：1  

Ming Zhao  Liang ChengZhipeng Zang 《Coastal Engineering》2010

Local scour around a submerged vertical circular cylinder in steady currents was studied both experimentally and numerically. The physical experiments were conducted for two different cylinder diameters with a range of cylinder height-to-diameter ratios. Transient scour depth at the stagnation point (upstream edge) of the cylinder was measured using the so-called conductivity scour probes. Three-dimensional (3D) seabed topography around each model cylinder was measured using a laser profiler. The effect of the height-to-diameter ratio on the scour depth was investigated. The experimental results show that the scour depth at the stagnation point is independent on cylinder height-to-diameter ratio when the later is smaller than 2. The increase rate of equilibrium scour depth with cylinder height increases with an increase in Shields parameter.  相似文献   

Methods for monitoring tidal flushing in large animal burrows in tropical mangrove swamps     

Suzanne E. Hollins  Scott F. Heron  Peter V. Ridd 《Estuarine, Coastal and Shelf Science》2009,82(4):615-620

The typically anaerobic nature of mangrove sediments provides significant challenges to the mangrove trees and biota inhabiting them. The burrowing activities and flow of water through the numerous and complex animal burrows perforating the sediments of mangroves have a major influence on the biogeochemistry of the sediments and are important to the enhancement of nutrient and oxygen exchange. Two new methods are presented for monitoring the tidal flushing of Sesarma messa and Alpheus cf macklay burrows in a Rhizophora stylosa mangrove forest – by measuring oxygen content of burrow water and by determining the change in fluorescence of a dye tracer through tidal inundation. A case study using the first of these showed oxygen consumption rates at the burrow wall deep within the burrow were found to be between 210 and 460 μmol O₂ m⁻² h⁻¹. The influx of oxygen during a flood tide was found to be significant and indicated that approximately 40% of the burrow water is flushed during a single tidal event. However, the high consumption rate of oxygen within the burrow resulted in the oxygen concentration remaining at or below one-third of the oxygen content of the flooding tidal water. A test application of the second method, using rhodamine dye as a tracer, indicated that the exchange of water between the burrow and the flooding tide was found to be in the order of 30% of the burrow volume. These new techniques provide a means to further study the nutrient exchange within these burrow systems and verify the initial findings that several tidal inundations are necessary to completely flush the burrows.  相似文献   

The restoration of fishing services and the conveyance of risk information in the Southern California Bight     

William S. Breffle  Kristen K. Maroney 《Marine Policy》2009

Southern California's marine areas are heavily contaminated with dichloro-diphenyl-trichloroethane (DDT) and polychlorinated-biphenyls (PCBs), and fish consumption advisories (FCAs) have been issued throughout the region. Between 2002 and 2003, the Montrose Angler Survey, a large-scale survey of subsistence anglers, was developed and implemented on site in Orange and Los Angeles counties. This survey was intended to assist natural resource trustees in the development of restoration programs that will address injuries to natural resources and restore lost economic services for anglers, but the data were never fully analyzed. The trustees have shown a clear preference for ecological restoration programs that may take years to improve fishing services. In contrast, this analysis, which includes a random-parameter fishing site choice model, demonstrates that simple, inexpensive programs such as better signage to warn of FCAs and transportation to clean sites have the potential to yield substantial benefits quickly. This paper also focuses on how different ethnic minority groups are affected by FCAs, and determines how best to communicate risk information and change fishing behavior through outreach programs.  相似文献   

Mesoscale physical processes and zooplankton transport-retention in the northern Norwegian shelf region     

Yiwu Zhu  Kurt S. Tande  Meng Zhou 《Deep Sea Research Part II: Topical Studies in Oceanography》2009,56(21-22):1922

Northern Norwegian shelf regions are highly productive, supporting fisheries rich in commercially important species such as cod, herring and capelin. It has been long recognized that the mesoscale jets, meanders and eddies associated with interactions between the North Atlantic Current, Norwegian Coastal Current and regional bottom topographic features such as troughs, banks and shelfbreaks play important roles in transporting and retaining zooplankton. To investigate zooplankton distributions and their correspondence with the physical fields, three large-scale surveys with mesoscale resolutions on physical and biological fields were conducted in northern Norwegian shelf regions between latitudes 68°15′N and 70°15′N in springs of 2000–2002. Survey results provide insights into the relationships between zooplankton distributions and the physical features such as fronts, the Norwegian Coastal Current and eddies related to topographic features. The physical and biological data are integrated and analyzed focusing on water types, estimation of geostrophic currents from direct current measurements, along-shelf transport of zooplankton, and retention of zooplankton by the mesoscale meander–eddy over a typical bank area on the shelf. The estimated mean transport in the upper 100 m on the shelf in the survey region is approximately 6.4×10³ tonnes wet weight day⁻¹ northward. High zooplankton abundances were found over both Malangsgrunnen and Sveinsgrunnen banks. The specific accumulation rate from northward–southward transport in the upper 100 m over Malangsgrunnen was approximately 0.08 day⁻¹, while variable currents with an offshore gradient of zooplankton abundance over Sveinsgrunnen implies an offshore dispersion of coastal-originated zooplankton cohort.  相似文献   

Effects of Body Weight and Water Temperature on Maximum Food Consumption of JuvenileSebastodes fuscescens (Houttuyn)     

谢松光  杨红生  周毅  张福绥 《中国海洋湖沼学报》2004,22(1)

1　INTRODUCTIONTherateoffoodconsumptionoffishfedadlibitumisregardedasthemaximumrateoffoodconsumption(Cmax) (Woottonetal.,1 980 ) .SeveralfactorsthatinfluenceCmaxincludingbodyweight (Liuetal.,1 998) ,watertemperature (Liuetal.,1 998) ,dis solvedoxygen (Vivekanandan ,1 977) ,salinity (ZanuyandCarrillo ,1 985 ) ,andphotoperiod (Grossetal.,1 965 ) ,werereported .Bodysizeandwatertemperaturewereregardedastwoofthemostimportantfactors,andhadreceivedmostattention (Elliott,1 979;Woottonetal.,1 …  相似文献   

基于生命周期的北京风味餐厅食物消费温室气体排放与减排案例分析     

张孟蓉  陈莎  李素梅 《气候变化研究进展》2021,17(2):140-150

减少粮食浪费不仅关乎粮食安全,而且对于温室气体减排与生态环境保护也至关重要.本文基于生命周期理论,构建了餐厅食物消费模型;然后通过对北京某风味餐厅的现场调研,量化评估了餐厅每人次产生的平均温室气体排放量,并对餐厅剩余食物产生的原因以及通过减少餐厅食物剩余带来的温室气体减排潜力进行了系统分析.研究结果表明,一个中等规模的...  相似文献   

局部角度域波传播步进算法研究   总被引：4，自引：2，他引：2       下载免费PDF全文

高静怀  周艳辉  毛剑  陈文超  吴如山  李幼铭 《地球物理学报》2007,50(1):248-259

本文从非均匀介质中波动方程出发,提出了基于一般标架的相空间（局部角度域）波传播的步进算法. 该方法在构造单程波的步进算法时,在选择标架或正交基等方面有更大的自由度. 我们以不随频率及深度变化且具有变尺度特性的Gabor_Daubechies紧标架为例,给出了单程波传输算子的具体形式及相应的波场步进算法;详细讨论了基于Gabor_Daubechies标架的传输算子的高频渐近展开问题,得出了在高频、小传输步长条件下传输算子的近似解析表达式,并给出使用条件. 通过模型算例,比较了精确传输算子与高频近似传输算子用于非均匀介质中波传播的结果,说明在一定条件下由两者得出的波场几乎是相同的.  相似文献   

一种新的地球物理反演方法——模拟原子跃迁反演法   总被引：17，自引：5，他引：12       下载免费PDF全文

师学明  王家映  易远元  苑新喜  王晓明  张云姝 《地球物理学报》2007,50(1):305-312

详细研究了一般地球物理反问题的迭代优化求解过程与物理学中原子跃迁过程的对应关系,建立了反演问题中模型空间、初始模型、局部极值模型、最优化模型等与原子的态空间、定态、激发态、基态等的对应关系. 在此基础上,模拟了物理学中原子从激发态向基态跃迁的物理过程,建立了一种与原子跃迁过程相对应的非线性随机跃迁数学模型和模型解跃迁搜索准则,导出了适用于一般地球物理资料的模拟原子跃迁的非线性反演算法. 用理论测试函数对这种新的反演方法进行了数值试验,结果表明该方法具有解不依赖于初始模型、收敛速度快等优点.  相似文献   

局地云量变化气候效应的数值模拟   总被引：3，自引：3，他引：3  

钱云  钱永甫 《高原气象》1994,13(2):169-177

本文用统计得到的东半球夏季平均云量资料，利用改进的云－辐射计算模式，在三维有限区域模式中模拟局地云量变化的气候效应。模拟结果表明，高原地区和热带辐合带云量变化造成的气候效应都主要表现在青藏高原地区。在低反照率时，高原地区云量减少使该地区地表加热，引起高低空气压系统加强；高反照率时结果相反。热带辐合带云量减少会引起青藏高原地区降温和气压系统减弱。  相似文献