Karst landscapes are unique landforms that result from the prolonged dissolution of groundwater in areas rich in limestone.
Limestone, consisting mainly of calcium carbonate, undergoes a chemical reaction in the presence of water and carbon dioxide, forming calcium bicarbonate. This compound is soluble in water, leading to the gradual formation and expansion of cavities.
The South Eurasian coast is particularly known for its karst plateaus, making the term "karst landscapes" a general reference to this topography in limestone areas.
Various factors influence the formation of karst landscapes. Climate, precipitation, temperature, and air pressure all impact the concentration of carbon dioxide in water, thereby affecting the karst process.
The presence of biology, including plants and animals, contributes organic matter to the soil, and the oxidation and decomposition of this matter release carbon dioxide, further influencing the karst phenomenon.
Additionally, tectonics, such as the creation of rock formations and joint structures, facilitate the vertical flow of water, thereby affecting karst development.
The lithology of an area, including the chemical and mineral composition of its rocks, also plays a significant role in karst action. Soluble rocks can be categorized into three main types: carbonate rocks (such as limestone and dolomite marl), sulfate rocks (including gypsum, hard gypsum, and mannite), and halite rocks (comprising potassium, sodium, magnesium salt rocks, and more).
Each of these rock types possesses distinct properties that impact the extent of karst action in various ways.
Karst landscapes can be classified into six main types. The first type occurs when surface water dissolves along joint surfaces or fissures in tuff, creating solution channels or troughs. As a result, the originally layered limestone separates into stalagmites or stalactites along these solution channels.
The second type occurs when surface water seeps downward along tuff fractures, eventually forming deep waterfall holes exceeding 100 meters in depth. The third type involves groundwater flowing laterally from waterfall holes into aquifers, resulting in the formation of caves.
The fourth type occurs when underground caves collapse, leading to the creation of collapse funnels in large areas or trap ponds in smaller areas. Lastly, the long-term combined effect of groundwater dissolution and collapse forms sloping valleys and natural bridges.
Based on outcrop conditions, karst landscapes can be categorized into three types: exposed karst, covered karst, and buried karst. Additionally, karst landscapes can be classified according to climate zones, resulting in five types: tropical karst, subtropical karst, temperate karst, boreal karst, and arid zone karst.
Moreover, there are four types of karst based on lithology: limestone karst, dolomite karst, gypsum karst, and salt karst.
Karst landscapes not only exhibit unique mountainous forms but also feature a variety of underground structures, including sinkholes, caves, and underground rivers. Rocks naturally possess pores and fissures, which serve as primary channels for water infiltration.
The larger the rock fissures, the more permeable the rock becomes, and consequently, the more significant the karst effect. In areas with well-developed karst landscapes, caves are larger in size, underground channels are more abundant, and the overall circulation network becomes more extensive over time.
