Numerical modeling of coastal aquifer karst processes by means of coupled simulations of density-driven flow and reactive solute transport phenomena

Abstract

Coastal karst features are supposed to be generated by the coupling between the infiltration of undersaturated rain water together with mixing from the fresh-saltwater interface. A coupled density-driven flow and reactive solute transport numerical model is presented which is able to duplicate conditions in such a morphogenetic conceptual model.

A review on natural and human-induced geohazards and impacts in karst

“…Many factors influence the chemical reactions involved in the dissolution of carbonate rocks, which ultimately lead to a wide variety of surface and underground features endemic of karst environments. At the interface between fresh and saline groundwater (Sáinz-García et al, 2011), or at the mixing zone between vadose and phreatic waters, different types of cavities may form (Dreybrodt et al, 2009). In young limestones close to the sea, enhanced dissolution at the interface between the freshwater body and the denser salt water gives rise to the so-called "flank margin caves" (Mylroie and Carew, 1990).…”

Groundwater Temperature as an Indicator of the Vulnerability of Karst Coastal Aquifers

“…The coupling of tidal oscillation with heterogeneity can, instead, reduce mixing [67]. In coastal cave genesis, dissolution generated by fresh and sea water mixing is higher than dissolution by meteoric water infiltration [68]. The dissolutional potential of brackish water in the transition zone of freshwater lenses is at the base of the "flank margin model", which explains the development of dissolution caves along the coast of the Bahama Islands [69].…”

Research on identification of critical factors and critical warning conditions under the perspective of safe groundwater exploitation ----- A Case Study on Safe Mining of Karst Water in Jiangsu Province, China

“…The quantitative or semi-quantitative early warning of soil cave destabilization is mainly based on mechanical equilibrium theory. Tharp (2003) carried out elastic-plastic mechanical mechanism modeling research on the relationship between cohesion, angle of internal friction, and hydraulic gradient of overburden in the process of karst soil cave development, and came up with the critical stress and strain critical early warning model for soil cave development; Gao et al (2009) analyzed the critical mechanical conditions of soil hole destabilization based on Mohr-Coulomb criterion and plastic equilibrium theory; García et al (2011) derived the coupled early warning model for the destabilization mechanics of karst soil holes through the study of the mechanics of the formation stage of the overlying karst soil holes; Xie et al (2014) combined with the engineering realities, explored the mechanics of the lower karst soil holes with the pile foundations above them in different developmental patterns, and established eight kinds of critical warning models for the destabilization mechanics of soil holes. kinds of critical warning models of soil cave instability mechanics; Sharapov et al (2015) analyzed the stability design parameters of the strip foundation through the engineering case of mechanistic coupling, and derived the critical mechanical warning model of karst soil cave collapse and instability; derived the critical warning model of collapse-causing instability through the mechanical modeling of the development process of overlying karst soil caves under the condition of falling water level, critical warning model of critical flow rate; Wu et al (2015) reasonably simplified and assumed the fissure dissolution process according to the dissolution mechanism, combined with the evolution and expansion conditions of single fissure soil cave, and established the critical mechanical warning model of soil cave destabilization and collapse; Chen et al (2017) researched the mechanical behaviors of soil cave development according to the conditions of the overall equilibrium mechanics, and derived the critical equilibrium of the overburden soil layer destabilization height warning model expression,and verified based on engineering examples.…”