总可捕量制度不同实施方式的比较分析

本文简单介绍了总可捕量制度（Total Allowable Catch,TAC制度）的概念及其实施所需的条件，对TAC制度的不同施式即“奥林区克自由捕捞式”（“free fishing like Olympic competiton”），个体配额制度（Individual Quota,IQ制度）或个体可转让配额制度（Individual Transferable Ouota,ITQ制度）进行了比较分析，并就我国如何实施TAC制度作了探讨。     

Work sharing in Kerala's fisheries

Earlier studies suggest that once population growth and market integration reach a certain critical level, traditional practices of work sharing tend to degenerate or disappear altogether. Work sharing has, however, survived to date in small-scale fisheries in Kerala, India. Artisanal fishermen strongly favor the system, for ethical reasons as well as for their personal benefit. Besides, boat owners appear not to be hindered by the system. Contrary to observations in crop production, work sharing has not inhibited the introduction of modern technologies like motorization.     

Polycyclic aromatic hydrocarbons (PAHs) and Pb isotopic ratios in a sediment core from Shilianghe Reservoir,eastern China: Implying pollution sources

The history records of polycyclic aromatic hydrocarbons (PAHs), lead and its stable isotope ratios were determined in a sediment core to receive anthropogenic impacts on the Shilianghe Reservoir in eastern China. The historical changes of PAHs concentrations, PAHs fluxes, Pb/Al and Pb isotope ratios showed a synchronous trend throughout the core, suggesting changes in energy usage and correlating closely with the experience of a rapid economic and industrial development of the catchment, Linyi City in eastern China. PAHs isomer ratios results reveal PAHs in sediments are dominantly anthropogenic pyrogenic source, dominated by the combustion of coal and biomass. Furthermore, the Pb isotopic composition also clearly indicates that coal combustion dust mainly contributed to the Pb burden in the reservoir sediments. Based on mix end member model of Pb isotope ratios, coal combustion dust dominated anthropogenic Pb sources over fifty years contributing from 31% to 62% of total Pb in sediment. And the contribution of leaded gasoline was low than average 25%. In addition, a stable increase of coal combustion source was found in sediment core, while the contribution of leaded gasoline had declined in recent decades, with the phase-out of leaded gasoline in China.     

Improving fisheries management in New Zealand: Developing dialogue between fisheries science and management (FSM) and ecosystem science and management (ESM)

This paper attempts to overcome the dichotomy between the broadly different and largely separate fisheries science and management (FSM) and ecosystem science and management (ESM) knowledge systems that characterise the international literature and are found in fisheries management practice in different countries. The paper argues that the construction of a heuristic we term the fisheries problematic, around issues and contexts, reveals the breadth of international fisheries management concerns and the variety of contexts in which these concerns are being faced. Adopting a political economy informed nature-society approach the paper considers ecological and socio-economic processes in their institutional settings in an attempt to shift from the either/or arguments around fish or ecosystems found in the FSM or ESM literatures to investigation that is grounded in understandings of the historically and geographically specific trajectories of fisheries related interactions and understandings of how knowledge about the trajectories and their interactions is fashioned. Drawing on recent conceptual innovations in the field, the paper develops a matrix-centred approach to explore ecological, industry, community and policy domains in New Zealand’s Quota Management System (QMS) and Individual Transferable Quota (ITQ) fisheries management regime. The extended framework prioritises scrutiny of the interaction amongst the four domains, as a strategy to help develop institutional frameworks that facilitate behaviours that are societally inclusive. The paper offers three conclusions. First, the landscape of New Zealand fisheries issues is very much a product of the contingent interaction of the QMS, a management regime designed around the principles of a FSM approach and laid down in a neo-liberal political environment and Maori aspirations encompassing the fisheries sector. Second, the conceptual mapping of FSM and ESM perspectives over New Zealand’s fisheries management experience highlights that a number of management issues have been down played by the commitment to FSM, a situation that has led to on-going tensions between commercial, recreational and customary stakeholders regarding fisheries management. Put another way, there is more to running a sustainable fishery (as defined in the Fisheries Act 1996) than QMS and other tools and dialogue about the development of these should be a priority. Third and more generally, improved dialogue on fisheries questions is likely to be most expeditiously advanced by studies that explicitly conceptualise and contextualise ecological and socio-economic processes and their institutional arrangements.     

Decision-tree analysis on optimal release of reservoir storage under typhoon warnings

The wet and dry seasons are distinctive in Taiwan as the amount of precipitation in wet seasons accounts for over three-fourth of the total rainfall. And the water-resources management relies pretty much on the rainfall brought in by typhoons as it accounts for a significant portion of the precipitation during wet seasons. Furthermore, as the storage of reservoirs is limited due to topographical factors, the management of typhoon rainfall has always been an important issue in Taiwan. The technique of decision-tree analysis is applied in this article to determine the optimal reservoir release in advance upon the issuance of a typhoon warning by the Central Weather Bureau (CWB), and the proposed methodology may provide solution to the trade-off judgment of reservoir operations between flood control and water supply according to economic efficiency. In this article, the economic loss functions of flooding damage and water-supply shortage are assumed in linear and nonlinear conditions, and the respective expected optimal releases based on the predicted precipitation as issued by CWB are derived. The proposed methodology has been applied to the Shihmen Reservoir System, and the capabilities of the model as an aid to real-time decision-making as well as the evaluation of the economic worth of forecasts is presented.     

Distribution and speciation of mercury in the Hongfeng Reservoir,Guizhou Province,China

The water, pore water, sediment, and fish samples were collected from the Hongfeng Reservoir in November 2003 and February 2004 in accordance with trace metal protocols. The average concentrations of total mercury （THg）, dissolved mercury （DHg）, reactive mercury, dissolved gaseous mercury, total methylmercury, and dissolved methylmercury in the water columns were 8.00, 5.70, 0.63, 0.05, 0.16, and 0.07 ng/L, respectively. THg and DHg in the water columns, THg in pore water and THg in lake sediments of the Hongfeng Reservoir showed the level of mercury in the Hongfeng Reservoir was higher than in other natural waters in the world due to the loading of a lot of waste water with relatively high concentrations of mercury, whereas methylmercury concentrations in fish （wet weight） varied from 1.73-51.00 ng/g, much lower than in most remote lakes and reservoirs reported in northern Europe and North America. Methylmercury distributions in pore water and sediments showed methylation occurred mainly in the upper several centimeters of sediment cores in the Hongfeng Reservoir. The concentrations of dissolved organic carbon, total suspended particles, total Hg, and methylmercury were higher at Houwu than those at Daba in November 2003. It is suggested that other pollutants such as N and P from fishing farm and other waste water at Houwu, which resulted in deterioration of water quality, affected the concentrations and distributions of mercury species in the reservoir.     

三峡库区秭归县膨胀土研究

秭归县膨胀土是继在三峡库区巫山县、奉节县和兴山县发现膨胀土之后发现的又一处膨胀土,从而揭示了三峡库区膨胀土的地域性。秭归县膨胀土与三峡其他地方的膨胀土一样发育于特殊的地质环境内,具有坡洪积成因和较均一土体结构。土的膨胀性主要取决于其中的蒙脱石,测试表明有效蒙脱石含量达18.67%,以中等混层比的伊利石/蒙脱石(I/S)混层矿物形式存在。土具有高塑限、高液限和低抗剪强度。判别表明,它达到了国内外膨胀土标准和界限。     

Nonlinear two-point flux approximation for modeling full-tensor effects in subsurface flow simulations

Subsurface flow models can exhibit strong full-tensor anisotropy due to either permeability or grid nonorthogonality effects. Upscaling procedures, for example, generate full-tensor effects on the coarse scale even for cases in which the underlying fine-scale permeability is isotropic. A multipoint flux approximation (MPFA) is often needed to accurately simulate flow for such systems. In this paper, we present and apply a different approach, nonlinear two-point flux approximation (NTPFA), for modeling systems with full-tensor effects. In NTPFA, transmissibility (which provides interblock connections) is determined from reference global flux and pressure fields for a specific flow problem. These fields can be generated using either fully resolved or approximate global simulations. The use of fully resolved simulations leads to an NTPFA method that corresponds to global upscaling procedures, while the use of approximate simulations gives a method corresponding to recently developed local–global techniques. For both approaches, NTPFA algorithms applicable to both single-scale full-tensor permeability systems and two-scale systems are described. A unified framework is introduced, which enables single-scale and two-scale problems to be viewed in a consistent manner. Extensive numerical results demonstrate that the global and local–global NTPFA techniques provide accurate flow predictions over wide parameter ranges for both single-scale and two-scale systems, though the global procedure is more accurate overall. The applicability of NTPFA to the simulation of two-phase flow in upscaled models is also demonstrated.