Fig.1. A night satellite photo of the Izera Mountains and surroundings. Some towns, state border (dashed line) and boundary of the Izera Dark-Sky Park (yellow line) are marked. The towns are seen from space at night as bright spots because outdoor lighting fixtures allow their light to escape upwards into sky (credit: NOAA).
Fig.2. Extend of the Izera Dark-Sky Park (blue line) marked on hypsometric map of Izera Mountains. Czech-Polish state border is drawn with white line.
darkness of Izera Mountains
The upper part of the Izera valley and the Jizerka valley are among most valuable regions in Czech-Polish borderland. Even though, there was large ecological disaster in the Izera Mountains in 80s of the last century as the result of which the mountains „lost” significant part of forests, they did not lost their greatest gem - vast peat bogs. Nowadays forests have started to cover Izera Mountains again - withered trees are replaced by the young ones. Nocturnal environment of the mountains is well preserved, especially in the Izera and Jizerka valleys. Although the night sky is here about 2 times brighter than the not light polluted sky, it is still much darker than the city sky where night sky brightness may be over 40 time larger than natural. It gave an opportunity to establish a dark sky park covering the mentioned valleys. Park includes the Izera valley (up to railway bridge before Harrachov station) and the Jizerka valley together with surrounding mountain ridges (see the map in Fig.2). Izera Dark-Sky Park fulfils two basic functions:
- education - conveying a knowledge about light pollution and opportunity to see a night sky much darker that the one, which is available to an ordinary inhabitant of a city,
- nature conservation - including darkness conservation in existing conservation of the Izera and Jizerka valleys (peat bogs reserves).
The above functions are accomplished by actions as follows:
- Educational materials (leaflets and information boards) available, especially, in places where tourists stay for the night (Orle, Chatka Górzystów, Jizerka). These materials would draw attention to the local dark sky (darker than city sky) and explain what light pollution is.
- Monitoring of the night environment condition by night sky brightness measurements and recording images with the use of all-sky camera. Results, available to everyone, will be used for scientific research and for educational activities.
- In the next step of the project, replacement of present outdoor lighting fixtures within the dark sky park with the ones minimizing light pollution. It would be a supplementary educational element.
Why these valleys in Izera Mountains were chosen for realization of dark sky park idea? Well, this area is sparsely populated and well shielded by mountain ridges form lights of towns and villages located in the Izera Mountains and in the vicinity. Moreover it is very interesting and environmentally valuable region, thus it is worth to include nocturnal darkness preservation in existing nature conservation. Additionally both valleys are easily accessible for tourists - this means quite large number of people, who can use educational values of this place. The realization of the project will undoubtedly bring benefits for nature not only of Izera Mountains and will help to draw society’s attention to the light pollution problem.
