Specialization and economic impact of the ports of Montreal,Quebec, Saint John,and Halifax

Specialization in cargoes and forelands is defined for the ports of Montreal, Quebec, Saint John, and Halifax using a variation of the location quotient. Economic impact is also defined using the location quotient. All ports are shown to have some degree of specialization; whereas, Saint John and Halifax have relatively greater economic impact. It is suggested that the four ports should be encouraged to develop their specializations. However, are the benefits to the shipping industry in following such a policy outweighed by the losses to the local economies because investment in certain ports does not take place?     

Evaluating erosion susceptibility for land‐use planning in coastal watersheds

Abstract

This paper reports on research conducted in support of a coastal zone management effort to reduce erosion and sedimentation impacts in a wetland watershed, Elkhorn Slough, Monterey County, California. The research reviews methods of determining soil erosion susceptibility and relating it to land‐use intensity within the watershed, measured by a land disturbance index. Erosion susceptibility is measured in three ways: by a combination of slope and the erosion factor of the Universal Soil Loss Equation; by field measurement of erosion and deposition on selected sites; and by computer‐assisted terrain analysis of data from secondary sources. Land use is shown to be a more important factor than landform in influencing relative erosion susceptibility.     

The Importance of Brokers in Collaborative Marine Ecosystem-Based Management of Social Ecological Systems

Abstract

Practitioners play a critical yet largely unexamined role in translating collaborative, ecosystem-based management (EBM) for social-ecological systems from theory to practice. We paired mental models and social network analytical methods and applied them to two cases of marine EBM in Rhode Island and New York, focusing on practitioners themselves, to understand the relationship between practitioners’ mental models of marine ecosystems and the extent and nature of collaboration within each network. Mental models analysis was used to assess the comprehensiveness and balance of practitioners’ mental models, and social network analysis was used to assess the role and influence of practitioners within each network. A comparative statistical analysis was then performed to understand the relationship between mental models and network measures. Research revealed a statistically significant correlation between practitioners’ mental model comprehensiveness and practitioners’ influence within the network. In other words, practitioners with comprehensive mental models of the ecosystem for which they were planning were found to act as “brokers,” connecting those who were not otherwise connected, bridging jurisdictions, sectors, and disciplines. Results underscore the importance of brokers in achieving the collaborative and integrated goals of EBM and suggest the need for greater attention to practitioners’ role in EBM implementation.     

A qualitative analysis of reintroducing cabotage onto New Zealand's coasts

This paper provides a qualitative analysis of the proposal to 'reintroduce cabotage' onto New Zealand's coasts. New Zealand's coastal shipping trade was opened up to international competition in 1995. The analysis is principally based on a stakeholder analysis of the 83 submissions received by the Shipping Industry Review team, as part of the Government's study to identify ways to increase participation in New Zealand's shipping industry. The stakeholders included New Zealand and international shipping companies, unions, industry associations, freight service providers, manufacturers and producers. The main conclusion drawn from the stakeholder analysis was that to reintroduce cabotage onto New Zealand's coasts would appear to have an overall net negative impact on the New Zealand economy at this stage. However, the Shipping Industry Review team 'was divided on the implementation of cabotage', and a force-field analysis was undertaken subsequently based on the author's stakeholder impact analysis and the Review team's list of pros and cons of reintroducing cabotage. This force-field analysis also supported the author's earlier conclusion. However, the almost 'complete absence of statistics' relating to the commercial activities of the shipping industry in New Zealand places severe limits on the analysis.     

Specialization and economic impact of the ports of Montreal, Quebec, Saint John, and Halifax

Specialization in cargoes and forelands is defined for the ports of Montreal, Quebec, Saint John, and Halifax using a variation of the location quotient. Economic impact is also defined using the location quotient. All ports are shown to have some degree of specialization; whereas, Saint John and Halifax have relatively greater economic impact. It is suggested that the four ports should be encouraged to develop their specializations. However, are the benefits to the shipping industry in following such a policy outweighed by the losses to the local economies because investment in certain ports does not take place?     

The incidence and effects of travellers' diarrhoea in a seafaring population

My bowels boiled and rested not: the days of affliction prevented me. (Job 30: 27.)     

Evidence of land use impacts of rapid transit systems

This paper draws from the findings of published empirical studies and observations of the impacts of rapid transit systems on urban development. Analysis is based on comparisons of impact findings by different researchers and for different cities. An initial set of key issues is proposed, against which available information is arrayed and compared. It is concluded that rapid transit can have substantial growth-focusing impacts, but only if other supporting factors are present.     

A model and algorithm for multicriteria route-mode choice

Using an idea proposed independently by Quandt and Schneider, the paper declares mode choice to be a special instance of route choice. It describes a (non-logit) model which includes in its route-choice mechanism the decision variables traditionally associated with mode choice. With the assumption that each traveller selects the route which minimizes his own personal linear choice function, it is clear that the routes with a nonzero chance of being picked are only those not dominated by any other path (e.g. are not both costlier and longer than any other path). The precise probability of a route being chosen is just the integral over the appropriate portion of the probability density of the coefficients of the choice function. The integration limits are implied by the amount of each disutility on each of the undominated routes. An algorithm is given which is quite efficient in finding these paths in a large and complex multimodal network.     

Flat versus differentiated transit pricing: What's a fair fare?

Virtually every U.S. bus system today charges its customers flat fares. Recent trends, however, suggest that passengers are traveling farther and proportionally more during peak hours, factors which have contributed toward transit's cost spiral. As deficits continue to soar and available funding tightens, current pricing rationales must be seriously questioned. This paper assesses the efficiency and equity impacts of three California transit agencies' fare structures. Short-distance, off-peak patrons are found to heavily cross-subsidize long-haul commuters. Fares differentiated by distance and time-of-day, in contrast, could improve the transit industry's fiscal posture while eliminating differences in payment rates. Barriers to their implementation remain formidable, however, both in terms of current fare collection capabilities and political acceptability.     

Wheel/Rail Non-linear Interactions With Coupling Between Vertical and Lateral Directions

Summary A theoretical model is developed to explore the high frequency wheel/rail interaction with coupling between the vertical and lateral directions. This coupling is introduced through the track dynamics due to the offset of the wheel/rail contact point from the rail centre line. Equivalent models of the railway track in the time domain are developed according to the rail vibration receptances in the frequency domain. The wheel is represented by a mass in each direction with no vertical-lateral coupling. The vertical wheel/rail interaction is generated through a non-linear Hertzian contact stiffness, allowing for the possibility of loss of contact between the wheel and rail. The lateral interaction is represented by a contact spring and a creep force damper in series and their values depend on the vertical contact force. The vibration source is the roughness on the wheel and rail contact surfaces which forms a relative displacement excitation in the vertical direction. Using the combined interaction model with this relative displacement excitation, the wheel/rail interactions with coupling between the vertical and lateral vibrations are simulated. It is found that the lateral interaction force caused by the offset is usually less than thirty percent of the vertical dynamic force. The lateral vibration of the rail is significantly reduced due to the presence of the lateral coupling, whereas the vertical interaction is almost unaffected by the lateral force.