Fine-scale analysis of GPS trajectories reveals spatial concentration and temporal intermittency of hiking activity in mountainous protected areas

Outdoor recreation exhibits marked spatiotemporal heterogeneity, yet coarse-resolution data can obscure localized intensity peaks and periods of low activity. Analyzing over 18 million GPS trajectory points, this study unravels hiking dynamics in the Beijing Baihua Mountain National Nature Reserve across annual, daily, and hourly scales. We establish a dual index framework measuring spatial coverage and activity intensity by aggregating point data into a 30-m spatial grid. The results highlight three insights. First, hiking activity exhibits significant spatial clustering within 11.06% of the study area, with topography and vegetation identified as most influential predictors. Second, pronounced temporal intermittency is evident, with no activity recorded during 57.62% of hourly intervals, whereas the peak hourly intensity in a single pixel exceeds the annual mean intensity across the study area by more than seven orders of magnitude. Third, spatial coverage and activity intensity exhibit a saturation pattern. Persistent and variable hiking use is concentrated in limited locations (7.23%), whereas most active locations (88.95%) are characterized by infrequent and relatively stable recorded use. Collectively, these findings demonstrate a highly confined spatiotemporal distribution, providing a basis for future assessments of potential human-wildlife overlap. The proposed framework provides a practical tool for quantifying the spatial distribution and temporal variability of recreational use, supporting dynamic visitor management and conservation planning in protected areas.