A landscape formed by the dissolution of soluble rocks such as limestone, dolomite, and gypsum, characterized by sinkholes, caves, and underground drainage systems.
Karst is a type of terrain formed primarily by the chemical dissolution of soluble bedrock, most commonly limestone and dolomite, by slightly acidic water. Karst landscapes are characterized by distinctive surface and subsurface features including sinkholes, sinking streams, springs, caves, and underground river systems. The hydrology of karst regions is fundamentally different from that of porous media aquifers because water flow is concentrated in enlarged fractures, conduits, and cave passages rather than distributed through intergranular pore spaces. This results in rapid groundwater velocities (meters per hour rather than meters per year), minimal natural filtration, and high vulnerability to contamination. Approximately 20-25% of the world's population depends on karst aquifers for drinking water. Karst springs can have very large and highly variable discharge, responding rapidly to recharge events. Understanding karst hydrology requires specialized techniques including dye tracing, spring monitoring, cave mapping, and geophysical surveys, as traditional methods based on porous media assumptions often fail in karst environments. Karst aquifers present unique challenges for groundwater protection, land use planning, and construction engineering due to their unpredictable subsurface voids and flow paths.