A framework for rating environmental value of urban parks.

In this study, indicators are proposed to characterize the intrinsic environmental properties and external value of urban parks. The intrinsic properties involve both acoustic factors and non-acoustic factors, such as visual aspects and size. To assess external value, the restoration level is defined, which measures the nearby presence of a quiet, 'green' area at residential areas outside parks. The restoration levels of green areas are based on intrinsic properties and the distances of each dwelling to urban park areas. The overall environmental value of a park, the group restoration level, is defined as a logarithmic summation of the restoration levels over its surrounding residential areas. Restoration levels were determined for sixteen public parks in the city of Rotterdam and compared with survey data from questionnaires. Results show that the investigated parks display a large variation in the group restoration level levels, mainly due to differences in size and average noise levels. To validate the proposed method, survey data from questionnaires are investigated as to correlation with restoration levels.

Impact of wind turbine noise in the Netherlands.

The Dutch government aims at an increase of wind energy up to 6 000 MW in 2020 by placing new wind turbines on land or offshore. At the same time, the existing noise legislation for wind turbines is being reconsidered. For the purpose of establishing a new noise reception limit value expressed in L den , the impact of wind turbine noise under the given policy targets needs to be explored. For this purpose, the consequences of different reception limit values for the new Dutch noise legislation have been studied, both in terms of effects on the population and regarding sustainable energy policy targets. On the basis of a nation-wide noise map containing all wind turbines in The Netherlands, it is calculated that 3% of the inhabitants of The Netherlands are currently exposed to noise from wind turbines above 28 dB(A) at the faηade. Newly established dose-response relationships indicate that about 1500 of these inhabitants are likely to be severely annoyed inside their dwellings. The available space for new wind turbines strongly depends on the noise limit value that will be chosen. This study suggests an outdoor A-weighted reception limit of L den = 45 dB as a trade-off between the need for protection against noise annoyance and the feasibility of national targets for renewable energy.