Visual assessment of the Green European Settlement Map : exploration and quality performance measures of the green component derived from the ESM algorithm

The urban green is currently at the core of scientific interest and policy-making in urban planning. The importance of the urban green component of the European Settlement Map (ESM) increases under the light of the absence of a homogenous layer in such coverage and resolution to be used in urban analysis. The ESM, the first European Map of the built-up, was initially published in July 2014. It is part of the URBA project initiated by the Joint Research Centre and funded by the Directorate-General for Regional and Urban Policy (DG REGIO). In the beginning, the ESM was not intended to provide a green layer. However, the urban green gradually started receiving increasing interest from the users of the ESM. Since there were spectral bands available in the Copernicus Core 003 dataset on which the ESM was adopted, eventually the green component was integrated with the built-up. This report addresses the quality assessment of the urban green component of the ESM defining thresholds over common vegetation indexes. The main purpose is to present reliable information about the dataset and test the possibility to move towards a new enhanced product if necessary, by deploying a post-processing method to decrease errors of omission and/or commission.