Long Term Monitoring of Air Pollution on Monuments and Cultural Heritage Sites in Cyprus Using Satellite Remote Sensing

Abstract

Although cultural heritage sites are documented and preserved, to date there has been limited monitoring and documentation of how cultural heritage sites are affected by air pollution. This paper aims to introduce a new approach for monitoring air pollution for areas near cultural heritage sites by using satellite remotely sensed data. This approach provides a cost-effective tool for local authorities and government agencies to identify the most polluted cultural heritage sites and make decisions regarding the conservation of these sites. Archived data may be used in order to study long term the impact of air pollution to cultural heritage sites. The study area includes significant open air monuments of Cyprus located in the four main cities of the island. In this paper the Limassol Castle is used as a focused case study. Three years of MODIS satellite data was evaluated and analyzed in order to categorize high risk long-term areas. Ground measurements using sun-photometers, spectro-radiometers and particulate matter (PM10) laser photometer were also utilized in the study. The darkest pixel atmospheric correction in conjunction with the use of the radiative transfer equation was applied to retrieve the aerosol optical thickness (AOT) from Landsat TM/ETM+ satellite images in order also to cross-validate the AOT values found from MODIS and sun-photometers. The results of the study indicate that air pollution is high in all the major cities in Cyprus near cultural heritage sites. The results also found that the Limassol castle was most affected by air pollution, while the other cultural heritage sites exhibited similar results.