Introductory editorial to the Topical Collection on “Engineering Problems in Karst”

Outcrops of karst rocks cover approximately 20% of the Earth’s continental surface and provide about 25% of the world’s drinking water. Karst systems can be extremely complex and, due to their unparalleled geological and hydrological intrinsic features, are among the most vulnerable settings in the world. These are commonly difficult environments from the engineering perspective that suffer from severe impacts and are the arena of a variety of natural and anthropogenic hazards (Parise and Gunn 2007; Gutierrez 2010). Such peculiar and sensitive environments require the application of specific approaches to foresee and reduce the negative effects of engineering projects, including human-induced hazards and impacts, allowing for sustainable development. Karst hydrology is particularly vulnerable to pollution events, groundwater withdrawal, construction of reservoirs, underground excavations, and land-use changes (Gutierrez et al. 2014; Stevanovic 2015). In addition, subsurface dissolution creates voids in carbonate and evaporite rocks that may propagate upwards leading to ground subsidence. These instability phenomena, including the occurrence of catastrophic collapse sinkholes, may severely damage any human structure and create serious difficulties to the design and development of engineering works. Management of karst environments is definitively a very delicate matter, which requires the participation of multidisciplinary teams with a proper understanding of their specific functioning and associated problems. Starting from these considerations, and from multiple years of experience on practical case studies in different regions of the world, a session was proposed on ‘‘Engineering Problems in Karst’’ on the occasion of the 12th Congress of the International Association of Engineering Geology (IAEG), held in Turin, Italy, September 15–19, 2014. The session was very successful (actually, among the most popular ones at the congress in terms of abstracts received: 26 papers submitted from 15 different countries). Following the invitation by Springer to prepare a Topical Collection from that session, the conveners worked with the Environmental Earth Sciences (EES) editorial staff to produce the outcome summarized here. This thematic issue includes expanded versions of twelve selected contributions from the session at the IAEG Congress, which have been rigorously peer-reviewed by international experts under the careful supervision of the Editorial Board of EES. One of the contributions presents a summary of the main types of engineering problems that can be encountered in karst, an environment characterized by distinctive landforms and by an extremely unique hydrological behavior, dominated by subsurface drainage. The focus in this contribution is specifically drawn on karst hydrology, and on This article is part of a Topical Collection in Environmental Earth Sciences on ‘‘Engineering Problems in Karst’’ guest edited by Mario Parise, Damien Closson, Francisco Gutierrez and Zoran Stevanovic.