ECOLOGICAL INFLUENCE OF ARTIFICIAL NIGHT LIGHT IN URBAN ENVIRONMENT AND LIGHT POLLUTION

The article explores holistic approach of understanding the importance of qualitative lighted urban environment. A city at night is quite different from the city during the daytime. In the evening, attention is focused on the effect of the light. Sustainable lighting should be: suitable to everyone, environmental acceptable and cost-effective. For successful light use there are many limitations which should be considered, such as: natural circumstances, urban requirements, users' demands, technological possibilities and nature conservation demands. Successful lighting arrangements provide best living condition to all. Artificial night light increase visibility and personal security, decrease vandalism and make better orientation possible. But too much light or light pointed in wrong direction increase unpleasant feeling, lowers the residential potential, provide high energetic costs due to energy loss and raises emission of warm house effect. Consequently biodiversity is harmed; ecosystems and all living creatures are affected. This negative environmental burden, known as light pollution, can't be simply abolished by turn off the light. During the research work a methodology of city lighting evaluation was developed. The paper delivers an explanation of evaluation criteria which should be considered in order to achieve the balance between conservation of positive lighting aspects and improvement of negative pollution effects. The study is useful as an innovative approach in spatial design as well as in the electric power economy. Clever lighting design allows achieving a high level of quality at low energetic costs. Lower costs mean more effective contribution to economic growth that indirectly also stimulate sustainable urban development.