Special attention has been paid to sustainable macroalgae cultivation in Europe. The question on where suitable cultivation areas lie, without conflicting with current marine socio-economic activities and respecting the environment, remains a great challenge. Considering 13 criteria critical to seaweed farming such as depth, shipping traffic, and distance to ports, this paper aimed to identify suitable and sustainable offshore areas on the West Coast of Sweden for the cultivation of the Sugar Kelp, Saccharina latissima. An integrated approach with the tools geographic information systems (GIS) and multi-criteria analysis (MCA) was used to aggregate the criteria by means of Boolean and weighted linear combination (WLC) techniques. The Boolean method singled out 544?km2 as suitable, whereas the WLC method indicated 475?km2 as highly suitable. Both techniques complement each other in finding optimal sites. Furthermore, the integrated models excelled in providing an overview for effective spatial decision-making that fosters sustainable development of macroalgae cultivations within marine and coastal systems.
Highlights
To the authors’ knowledge no study on seaweed aquaculture site selection has been conducted using such a range of criteria with the purpose of including sustainability aspects within a comparative GIS-MCDA.
The large areas identified on the West Coast of Sweden as suitable highlight the potential of this new industry and the complexity of associated marine spatial planning.
Boolean and weighted linear combination methods were applied and compared, providing valuable insights in the selection of methods for spatial decision-making support. These insights should support a more sustainable development of macroalgae cultivation in the region, as well as a more resilient marine spatial planning process for blue growth strategies.
Public–private partnerships (PPPs) play an important role in bringing private sector competition to public monopolies in infrastructure development and service provision and in merging the resources of both public and private sectors to better serve the public needs. However, in worldwide practices, there are mixed results, substantial controversy, criticism and conflict over PPPs. This paper proposes a systematic framework for the delivery of public works and services through PPPs in general. Justified by public procurement principles, aimed at a public–private win–win solution, and based on worldwide best industrial practices and lessons from unsuccessful projects, this framework integrates the four broadly divided stages that repeat over time: (1) design of a workable concession, (2) competitive concessionaire selection, (3) financial regulation, and (4) periodic reconcession and rebidding. The four-stage framework takes into account the requirements of public services, realignment of responsibility and reward among multiple participants in PPPs, the monopolistic rights of the concessionaire, and the wide range of risks and uncertainties in the long concession period. Varying competition elements are incorporated in each of the four stages for continuous performance improvement in the delivery of public works and services. The design of the right concession forms the base on which other stages are implemented in addition to planning the project and allocating risks for enhanced efficiency. The financial regulation allows the government to address changing conditions and to regulate the concession for efficient operation with due discretion, whereas the competitive concessionaire selection and periodic reconcession and rebidding play critical roles in achieving innovation, efficiency and cost effectiveness through direct competition rather than government discretionary intervention. 相似文献
Building on earlier work to incorporate real option methodologies into network modeling, two models are proposed. The first is the network option design problem, which maximizes the expanded net present value of a network investment as a function of network design variables with the option to defer the committed design investment. The problem is shown to be a generalized version of the network design problem and the multi-period network design problem. A heuristic based on radial basis functions is used to solve the problem for continuous link expansion with congestion effects. The second model is a link investment deferral option set, which decomposes the network investment deferral option into individual, interacting link or project investments. This model is a project selection problem under uncertainty, where each link or project can be deferred such that the expanded net present value is maximized. The option is defined in such a way that a lower bound can be solved using an exact method based on multi-option least squares Monte Carlo simulation. Numerical tests are conducted with the classical Sioux Falls network and compared to earlier published results. 相似文献