Karst collapse susceptibility mapping considering peak ground acceleration in a rapidly growing urban area

Karst collapse occurrences represent a geological hazard that can cause damage to man-made structures. In the present study, a karst collapse susceptibility map was produced using a multivariate statistical method and a Geographical Information System. The case under study is the northern suburbs of Athens (Greece). The karstic features of the study area were recorded. Physical processes (slope angle and aspect, hydrographic network, springs, lithology, tectonic features) along with anthropogenic (road network and land use) parameters were chosen as major factors affecting the karst collapse occurrences. The innovative method was combining karst collapse occurrences with seismic hazard assessment, which was achieved by calculating peak ground acceleration (PGA). The PGA was determined for a return period of 475 years, corresponding to a 90% probability of not being exceeded in 50 years. The logistic regression (LR) method was applied to evaluate these factors. Slope angle, PGA, lithology, and distance to springs and roads were statistically significant for the applied model. Among these factors, the slope angle and PGA have a negative effect, while the lithology, and distance to springs and roads have a positive effect on the karst collapse occurrences. The validation of the applied LR model indicated that the results are reliable and that the produced map is accurate. The karst collapse susceptibility map was classified into four classes. The areas of very high and high susceptibility were observed mainly in the eastern and southwestern parts of the study area. Almost 30% of the existing urban growth boundary of the study area is located in areas of very high and high susceptibility. The karst collapse susceptibility map can be used by planners and engineers for sustainable urban development.