Mendes,Ricardo NogueiraMagalhães,Maria Filomena deMikhno,Yuliya2026-05-112026-05-112026http://hdl.handle.net/10400.5/118433Tese de Mestrado, Ecologia e Gestão Ambiental, 2026, Universidade de Lisboa, Faculdade de CiênciasOutdoor recreation in peri-urban natural parks is raising concerns about intensive trail use and conflicts among users. The Serra de Sintra (Sintra-Cascais Natural Park, Portugal) is heavily visited by hikers and mountain bikers. This study uses Volunteered Geographic Information (VGI) to map trail use patterns, identify and map the distribution of hiking and biking activities, quantify areas of user overlap (conflict risk), and assess non-compliance with park regulations. GPS track data were downloaded from GPSies (2017) and Wikiloc (2025), processed in GIS, and overloaded on the park’s official trail network. A 25×25 m grid was used to quantify use intensity, and overlap analysis identified segments used by both hikers and bikers. Results show that hikers generally concentrate on established scenic trails, whereas mountain bikers display a broader spatial dispersion. There is a dense informal network of bike routes beyond the official plan, often crossing sensitive habitats. Overlap between groups is limited to certain corridors (e.g. core trails to Pena Palace), highlighting priority areas for conflict management. Between 2017 and 2025 the overall trail use remained high, and spatial patterns of use by hikers and bikers across the park remained similar. These findings provide actionable spatial knowledge, and offer practical insights that can guide management decisions. Signage should be reinforced along heavily visited corridors, particularly in overlap zones where hikers and bikers converge, such as the central ridge and the main access routes to Pena Palace. Clear wayfinding and trail etiquette signs in these areas would help reduce congestion and conflicts. Additionally, targeted signage in gardens and heritage precincts can guide visitors to stay on designated paths and respect carrying capacity limits.application/pdfengProtected areasHikingMountain BikingSpatial analysisVolunteered Geographic Informationmaster thesis