Morphometric analysis of karst depressions on a mediterranean karst massif

Abstract

Dolines are the most typical landform in karst landscapes. They play an important role in karst hydrogeology; they are effective sediment traps that provide information about past climates and karst evolution, and can also be indicators of tectonic activity. The morphometic analysis of those depressions can help in their study and interpretation. However, detailed identification and delineation of dolines becomes increasingly difficult when the study area is very large, of limited access or covered by vegetation. Here, we have used a method developed by the authors for automatic identification and delineation of karst depressions based on the use of a pit removal algorithm. Next a complete morphometric analysis of the karst depressions has been carried out. The main advantage of the methodology is that by delineating and identifying the depth of each doline from its rim, many morphometric statistics can be obtained, including the relation of doline depth and area with respect to altitude, the main doline orientations, doline density, the fractal dimension of doline area and frequency, and point field analysis, among others. The results are interpreted from a geomorphological point of view and the mapped dolines can be easily integrated into geomorphological mapping. A case study is presented from the large Sierra Gorda karst massif in southern Spain, where 3100 depressions have been identified. A strong structural control of doline shape and orientation is demonstrated; the main areas of doline density are highlighted and doline size is shown to follow a fractal law.

Key words:

• sinkholes
• dolines
• fractal
• morphometry
• orientation
• point field

Acknowledgements

This study was supported by Research Project CGL2015‐71510‐R, KARSTCLIMA, Spanish Ministry of Economy and Competitiveness. The authors would like to thank Dr Tamás Telbisz and an anonymous reviewer for their constructive criticism that has contributed to improve the final version of this work.

Additional information

Notes on contributors

Eulogio Pardo‐igúzquiza

Eulogio Pardo‐Igúzquiza, Juan J. Durán, Instituto Geológico y Minero de España (IGME), Ríos Rosas, 23, 28003 Madrid, Spain Email: [email protected], [email protected]

Antonio Pulido‐bosch

Antonio Pulido‐Bosch, Departamento de Biología y Geología, Universidad de Almería, Ctra. Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain Email: [email protected]

Manuel López‐chicano

Manuel López‐Chicano, Departamento de Geodinámica, Universidad de Granada Campus Fuentenueva s/n, 18071 Granada, Spain Email: [email protected]