Is Germany experiencing urban or suburban growth? Contrasting three different urbanization classifications

Recent accounts of urbanization and suburbanization trends relying on administrative geographical units have been criticized for not capturing the nuances of the urban-rural gradient. In this context, methods based on remotely sensed data have proven valuable for assessing the share of urban land at a high spatial resolution. Yet, such methods have rarely been used for population analysis along the urban-rural gradient. This paper addresses these issues by exploring how classifying the urban gradient alters findings on urban, suburban, and periurban population change trends. For this, we contrast a recently proposed urban gradient classification based on urban morphological data with a population density focused and a functional classification. The different urban gradient classifications are applied to gridded and administrative census population data to analyze urban and suburban population change trends in German metropolitan regions from 2011 to 2022.