This study presents an integrated and reproducible framework for assessing the changes and trends in urban green areas by combining Copernicus Land Monitoring Services (CLMS) data with local in-situ datasets. The method is tested and demonstrated on the City Master Plan of Ruse Municipality, Bulgaria. It uses the High-Resolution Phenology and Productivity (HR-VPP) product as part of the Copernicus Land Monitoring Service (CLMS), managed by the European Environment Agency. These results are validated against orthophotos, cadastral records, and mandatory municipal planning data City Master Plan - the legally defined territorial units of dedicated land use– so-called “functional zones”. The methodology uses the ISO 19144-2 compliant land cover characterization to allow a standardized description of functional zoning (“urban bricks”) derived from the municipal Master Plan, and tailored interpretation of the CLMS-derived metrics on urban green areas. Results indicate an approximate 7% decline in green residential areas in the period 2017–2023, accompanied by significant spatial disparities between dense urban zones and peripheral areas. The proposed framework demonstrates the added value of integrating Earth Observation (EO) data with in situ sources, improving reliability and supporting implementation of EU environmental policies, such as the Nature Restoration Regulation. The target users of the approach as the state and local administration, thus, the approach is designed to be intuitive, understandable, and easy to implement in the local context. The approach is scalable and transferable to other European regions and countries.
Milenov et al. (Wed,) studied this question.