Updated doline inventory and revision of geomorphological aspects that influence karst development at the Garraf Mountain Range, Catalonia, Spain

The Garraf Mountain Range (GMR), located in Catalonia (NE Spain), is a calcareous karstic region subjected to intense anthropogenic pressure, mainly related to urban development and extractive activities. Using a new LiDAR-derived Digital Elevation Model (DEM) with a spatial resolution of 2 × 2 m, we updated the doline inventory, increasing the number of mapped collapse dolines from 710 to 968. The main objective of this study is to provide a preliminary characterization of the spatial distribution of the updated doline dataset across the entire GMR in relation to hydrological processes and geological hazards. Factors influencing karst development-such as lithology, regional lineaments, drainage network, slope, and elevation-were analyzed. Based on these parameters, four distinct geomorphological blocks were identified within the GMR: Calafell, Ordal-Vilanova i la Geltrú, Central, and Pallejà-Gavà. No direct spatial correlation was observed between doline occurrence and proximity to structural lineaments. In contrast, dolines are preferentially associated with river channels and areas of high drainage density, which themselves show a strong structural control in their orientation. These relationships help define preferential pathways for surface runoff and infiltration, which are critical for quantifying karst capture in water-balance assessments of GMR watersheds. Additionally, high doline densities were identified near urban areas, landfills, and quarries, particularly in the northeastern and southeastern sectors of the GMR, notably around the municipalities of Vallirana and eastern Sitges. The updated doline inventory provides a valuable basis for improving the accuracy of hydrological balance studies and karst-related hazard assessments in the Garraf Mountain Range.