A Spatial Footprint Assessment Method for Mapping Port Transformation Areas: An Application to the Italian Ports Database

The Italian coastal zone is a dynamic and fragile environment that is characterized by high ecological vulnerability and subjected to strong anthropogenic pressures that significantly alter its natural morphology and environmental balance. In this scenario, port infrastructures represent about 35% of the Italian artificial coast and have a significant influence on coastal dynamics and seabed integrity. This study proposes a new methodology based on polygon-based mapping to calculate the spatial extent and distribution of the transformation areas associated with port development. This allows us to define a new specific indicator, named the Port Pressure Indicator, to assess the impact of port infrastructures. The proposed analysis highlights that port-related pressures on the marine-coastal zone are driven by two main factors: large-scale ports, which account for more than half of the total transformation areas, and a widespread network of minor ports, which are responsible for the systematic fragmentation of coastal continuity. By providing a standardized measurement of transformation areas, this approach supports coastal spatial planning and monitoring. Moreover, it provides a baseline for assessing spatial pressure and supporting integrated coastal zone management assessments.