*2.2. Applications of Remote Sensing Technologies in Environmental Monitoring and Environmental Law Enforcement*

Remote sensing is used in numerous fields for environmental purposes. Remote sensing has provided the means for detecting and quantifying the rates of pollution, as well as for mapping and monitoring sources of pollution and the degree of remediation for their management. It has the means to respond and facilitate environmental management, and makes sound and evidence-based decisions in relation to Earth's resources at a global scale and across different continents, nations, and domains (Mertikas et al. 2021). Such a collection of environmental monitoring data through remote sensing technologies is undoubtedly essential for the effective decision making of environmental authorities.

Simultaneously, the most important applications of remote sensing technologies in environmental law enforcement consist of their use from public authorities for their work (duty) known as "environmental compliance assurance". Environmental compliance assurance describes all the ways in which public authorities promote, monitor and enforce compliance with environmental law. Through the Copernicus program and the relevant EU action plan, the EU Commission promotes the use of satellite images and other geospatial data resources to detect illegal disposal of waste, illegal land use and other breaches<sup>4</sup> . Earth observation technology may also contribute to implementing and ensuring compliance with multilateral environmental agreements (Kuriyama 2005) and they have been actually used to monitor the implementation of environmental agreements such as the World Heritage Convention, the Convention of Biological Diversity, the Ramsar Convention, the UN Convention to Combat Desertification, and the UN Framework Convention on Climate Change. In some countries, such as the Netherlands, earth observation technology is also used in the preparation of 'environmental impact reports' to obtain permits for new water projects, in order to verify their compliance with the legal framework<sup>5</sup> . Another significant application of remote sensing technologies in environmental law enforcement refers to collecting reliable information that can provide solid evidence to combat environmental crime (Patias et al. 2020). However, remote sensing technologies as means of proof are subject to certain limitations and are therefore preferably used as complementary means of proof. In particular, data collected by remote sensing technologies are of digital nature which means that they are subject to alterations and thus need to be verified<sup>6</sup> . In addition, strict control of the whole process of data collection and interpretation is essential, from the moment the data is obtained, in order to avoid wrong evidence (Laituri 2018).
