Modeling the Influence of Roundabout Deflection on Its Efficiency as a Noise Abatement Measure

Challenges that emerge in roundabout design are mostly related to space constrictions and provision of appropriate deflection around the central island. This can result in speed profiles on roundabouts that might reduce their potential as a noise abatement measure. Because of this, the impact of a roundabout on noise levels and its applicability as a traffic calming device and a noise abatement measure should be investigated in the early design stage, by modeling noise levels. In this paper, the following hypothesis is tested: vehicle movement trajectories, defined during the fastest path performance check in roundabout early design phase, can be used as the road traffic noise sources when modeling noise at roundabouts using static noise model. This procedure (1) simplifies the preparation of the noise model, (2) results in a model that is closer to the real-world in terms of traffic flow conditions, (3) allows the noise calculations in the early stages of roundabout design, and (4) includes the influence of roundabout deflection on calculated noise levels. The abovementioned simplifications of the road traffic noise modeling process should encourage the optimization of roundabout geometry in terms of its noise reduction capabilities in the preliminary design phase of these intersections.

A Differential Game of Ecological Compensation Criterion for Transboundary Pollution Abatement under Learning by Doing

This paper studies a stochastic differential game of transboundary pollution abatement between two kinds of ecological compensation and the abatement policy, in which the learning by doing is taken into account. Emission and pollution abatement between upstream and downstream region in the same basin is a Stackelberg game, and the downstream regions provide economic compensation for pollution abatement in the upstream region. We discuss the feedback Nash equilibrium strategies of proportional compensation and investment compensation, and it is found that an appropriate ecological compensation ratio can improve the investment level of pollution abatement in the two regions by accumulating experience in the process of learning by doing. In the long term, the investment compensation mechanism is an effective transboundary pollution abatement measure that can continuously reduce the water pollution stock in the upstream and downstream.

El control de la contaminación por nitratos en el regadío

This paper analyzes the effects of some water management policies and irrigation systems on crop yields and water pollution, in an area located in the Flumen- Monegros irrigation district in Huesca (Spain). The analysis is performed using water and nitrogen crop response functions, which are estimated with the EPIC crop growth package. The estimation of response for the crop activities incorporates information on local climate, soils, crop management and irrigation systems. The relationship between yields and water and nitrogen input use is examined, in order to quantify the pollution reduction cost faced by farmers. The costs depend on the particular crop and the pollution abatement measure, and information on these costs is important to design efficient pollution abatement measures.

Geosequestration in Australia: Existing and Proposed Regulatory Mechanisms

Geosequestration1 involves the capture (from power stations and other facilities) and storage of carbon dioxide for very long periods of time in underground geological formations. This article is concerned with key legal and regulatory issues associated with establishing and operating geosequestration projects in Australia. It highlights the recent increased interest in, and raised profile of, using geosequestration as a greenhouse gas abatement measure in Australia. It reviews the cooperative efforts of the States, Territories and the Commonwealth to develop a nationally consistent regulatory framework for geosequestration projects, using existing petroleum legislation. These efforts have been driven by a lack of existing Australian legislation that provides an adequate and discrete regime dealing with the issues of responsibility and liability for geosequestered gas, although the release of draft legislation in this area is now imminent. It assesses some State legislative attempts to allow for the underground storage of carbon dioxide, and argues that these fail to satisfactorily deal with the long term (indefinite) nature of the storage aspect of geosequestration projects. Finally, this article examines the States' and Commonwealth's powers to legislate in respect of the injection and storage of carbon dioxide.