生态水文学:生态需水及其与流速因素的相互作用

本文研究涉及生态水文学中生态需水问题的一般认知。探讨了生态系统动态变化与水流驱动力因素之间的关系，重点探讨水流驱动因素中的关键指标——流速，通过分析流速与生态系统相互作用，从生态水文学动力因素出发估算生态需水；基于生态流速和水力半径，提出考虑河道内生态需水与水力因素关系的生态水力半径法，充分利用水生生物信息（鱼类产卵洄游流速）与河道信息（水位、流速、糙率等）估算河道内生态需水；归纳生态水力半径法在生态需水计算中的初步应用：考虑污染物降解耦合水量水质的生态需水计算、考虑鱼类等生物对流速要求的生态需水计算、考虑河道冲淤平衡的输沙需水量计算等方面。本文提出的生态流速研究既包括生物生长发育适宜的流速，又包括流速大小变化所涉及的许多动力因素，旨在延伸与扩展生态水文学的内涵与应用。     

Synthetic isoseismals of two Californian earthquakes

Comparison between the observed and the synthesized isoseismals of the relatively small earthquake of Sierra Madre (1991) and of the big one in San Francisco (1906), California, suggests that sometimes the areal shapes of the territories damaged by earthquakes might be synthetically traced out with a simple kinematic function which, following the asymptotic approach, takes into account some gross features of the sources. The rather good fits presented herein may indicate the possibility of substituting in some regions the so-called empirical attenuation relations, which are currently used in regional seismic hazard studies, by new more source-dependent algorithms. Conversely, the technique could help in retrieving information about sources of earthquakes from the pre-instrumental era, (i) in areas where it could be proved that the effects due to the travel paths and to local site conditions are negligible, (ii) when the detailed modelling techniques nowadays available are inapplicable due to lack of data, or (iii) for saving time and money. It seems that the algorithm gives rather stable results.Formerly: LIVIO SIRO.     

Organizing coordination in a public marine research and management advice organization: The case of the Norwegian Institute of Marine Research

Public organizations involved in marine management are increasingly confronted with coordination challenges in marine governance. This study examines why and how the Norwegian Institute of Marine Research (IMR) reorganized its formal coordination structures between the areas of fisheries management and marine environmental management. The findings indicate that organizing efficient and, at the same time, legitimate coordination structures between different areas of marine governance is a “wicked” organizational problem with no ultimate and single optimal solution. In contrast to the assumptions of classical organization and management theory, the study finds that the reorganization of formal coordination structures is not necessarily driven for reasons of efficiency and perceived coordination problems. Instead, public marine management organizations also change their organizational structures to live up to external expectations to adopt modern management concepts, such as the Ecosystem Approach to Management (EAM). However, the study indicates that the adoption of the EAM has stimulated coordination and integration efforts in the research and advisory activities of the IMR.     

Exploring the applicability of biological and socioeconomic tools in developing EAFM plans for data absent areas: Spinner dolphin EAFM for Kalpitiya,Sri Lanka

The ecosystem approach to fisheries management (EAFM) methodology is currently considered the preferred option for long-term sustainability of fisheries and ecosystem services and is widely popularised. Manuals, guidelines and training have been given to many nations, but the actual existence and execution of an EAFM plan is rare. The applicability and relevance of biological and socioeconomic tools to follow EAFM planning guidelines in a data absent area were explored in Kalpitiya, northwest Sri Lanka, where there is a population of spinner dolphins that the local community are especially dependent on through tuna-dolphin association fishing and dolphin-watching tourism. This paper provides background to the design and collection of information leading to the formulation of an EAFM management plan. Scoping and the determination of a fishery management area were completed through stakeholder consultations using a combination of interviewer-administered questionnaires, interviews, meetings, dolphin distribution data and existing management plans. Threats and stakeholder prioritisation were compiled and the final agreed fisheries management area covers a total area of 2445 km² adjacent to the Kalpitiya peninsula. The completed EAFM plan contains 4 goals, 16 actions and 72 sub-actions agreed by stakeholders. It was concluded that both willingness of higher level stakeholders responsible for implementing regulations and working with grass-root level stakeholders are critical in developing a realistic and implementable EAFM plan. This work also highlights how data absence should not remain the bottleneck that hinders moving forward with EAFM approaches.     

Modeling the Stakeholder Profile in Territorial Management: The Segarra-Garrigues Irrigation System,Spain

Interest in obtaining a more accurate snapshot of irrigation management from a geographical perspective is increasingly relevant. This proposal is based on existing qualitative approaches in combination with an alternative method (the territorial irrigation management model) to identify and present key stakeholders attitudes and perceptions in the Segarra-Garrigues irrigation system in Spain. Advantages are (1) the focus on interrelations and context, (2) the applicability and extrapolation of the irrigation system, and (3) the irrigator-driven rather than researcher-driven perspective. Results revealed that there are conceptual and practical heterogeneities between the preferences of stakeholders' groups regarding water resources management, environmental protection, and agricultural challenges.     

Socioeconomic characteristics and crash injury exposure: A case study in Florida using two-step floating catchment area method

The objective of this study is to investigate the exposure of different population groups to severe injury crash hotspots using an empirical-Gaussian two-step floating catchment area (EG-2SFCA) method based on roadway network distances and a socioeconomic-based weighting approach. This is performed by developing a special form of a crash-to-population ratio index that incorporates the severe crash hotspots relative to the locations of populations they might impact. While identifying these hotspots, four different age groups are considered: 17 and younger, 18 to 21, 22 to 64 and 65 and older. For each age group, severe crash hotspots are identified based on the roadway network and the number of severely injured crash occupants that belong to the specific age group. Using these age-specific crash hotspots and the EG-2SFCA method, communities that were exposed to elevated crash injury risk (crash injury exposure) have been identified. Furthermore, from a residential perspective, a socioeconomic analysis is conducted in order to develop a socioeconomics-based crash injury exposure measure. This measure assesses the exposure of different socioeconomic groups to the risk of being injured. Results demonstrated by applying this measure in the Tampa Bay region, FL show that different population groups are under varying risk of being injured depending on their residential location. The developed approach has the potential to be a social fairness measure able to be applied by agencies, which could enhance the well-being of communities that are subject to elevated injury risk.     

Ultimate Strength of Ship Plating under Axial Compression

The failure of a ship hull girder is governed by buckling and plastic collapse of the deck, bottom and side shell steel stiffened plates. The stiffened steel plating in ships is generally subjected to both in-plane and out-of-plane loading and is more important to understand the characteristics of these panels under buckling. Tests are reported on the collapse load of stiffened plates with and without cutout and with reinforced cutout under uniaxial compression. A generalized computer program for the semi-analytical solutions proposed by various investigators based on strut approach and orthotropic plate approach, and a finite element analysis program based on orthotropic plate approach are developed. The panels are also analysed using the finite element analysis software ANSYS. An approximate method based on strut approach is proposed to calculate the collapse load of stiffened plates with cutouts and initial imperfections. The reduction in strength of the panels due to the presence of square cutout, rectangular cutout and increase in strength due to reinforcement around rectangular cutout are calculated based on the test results. Comparisons are made between the test results and predictions based on semi-analytical solutions and finite element analyses, and the uncertainty parameters calculated are discussed. Based on this study it is concluded that the cutout can be reinforced with a maximum increase in strength up to 19% for plate initiated failures.     

Scour below pipelines and around vertical piles in random waves

An approach by which the scour depth and scour width below a fixed pipeline and scour depth around a circular vertical pile in random waves can be derived is presented. Here, the scour depth formulas by Sumer and Fredsøe [ASCE J. Waterw., Port, Coastal Ocean Eng. 116 (1990) 307] for pipelines and Sumer et al. [ASCE J. Waterw., Port, Coastal Ocean Eng. 114 (1992) 599] for vertical piles as well as the scour width formula by Sumer and Fredsøe [The Mechanics of Scour in the Marine Environment, World Scientific, Singapore, 2002] for pipelines combined with describing the waves as a stationary Gaussian narrow-band random process are used to derive the cumulative distribution functions of the scour depths and width. Comparisons are made between the present approach and random wave scour data. Tentative approaches to related random wave scour cases are also suggested.     

一类非线性系统次优控制的灵敏度法

本文研究一类非线性定常系统的次优控制问题。通过在系统中引入 1个灵敏度参数并将系统变量关于灵敏度参数展开 Maclaurin级数 ,使求解最优控制的非线性两点边值问题化为一族线性两点边值问题。利用截取最优控制级数的有限项求得系统的次优控制律。仿真实例表明 ,该方法对非线性系统次优控制律的设计是有效的