Rediscovering Valley Hillslopes: Their Forms, Uses, and Considerations in Urban Planning Documents

Re-considering the interactions between society and natural resources is fundamental in pursuing sustainability and adaptation to climate change in cities. The representation in urban planning instruments reveals an inadequate consideration of valley hillslopes as interface systems or as ‘places’ with possible multiple roles and meanings for populations. Beyond landslide and flooding considerations, valley hillslopes are scarcely identified as distinct entities from the valley and the plateau, investigated as sites of diverse possible uses, and analysed in terms of which variables related to the relief’s forms influence their use. Confronting urban planning instruments that reduce slopes to building spaces, this contribution advocates for a specific representation of valley hillslopes, highlighting the environment’s variety within which the system interacts, the diversity of uses, and the interrelationships between form and land cover. By combining GIS mapping and statistical analysis, this research proposes a multi-scalar approach based on identifying valley hillslopes delineated trough minimum units (geochore), integrated with land cover clustering and an analysis of the potential relations between land cover and six explanatory variables. The research points out the singularity and complexity of valley hillslopes, which should be incorporated into urban planning policy as potential cultural, ecological, or recreational resources for populations.