Mapping Urban Green Space

Urban green, here defined as the presence of vegetation within urban space, is a crucial dimension when discussing livability, recreation and public health in cities. There is academic and policy consensus of the ample benefits in relation to the presence of green, but space in urban environments is a scarce resource subject to multiple and sometimes conflicting land use claims (a.o. residential, commercial and transport infrastructure). Sometimes green spaces are lost in favour of more pressing needs, while on other occasions, green is added displacing other land uses. Monitoring and understanding the spatial and temporal dynamics of urban green is essential for sustainable urban planning. Beyond the percentage of total green space in a city, it is important to know ”where” green space was lost or added in order to understand which residents have less or more access to green and, with such awareness, planners can create proposals to mitigate or expand local changes. This tutorial offers step-by-step instructions on acquiring high resolution satellite images from 2 moments in time, calculating NDVI index, classifying index into Green, Water and Other classes, and calculating the transition matrix to understand the green changes. It uses Dutch open data and open source software (QGIS).