Karst landscapes are geographically widespread and are developed predominantly on a variety of carbonate rocks, although areas of limestones, gypsum and hydrogenic rocks are also affected in certain regions. The term ‘karst’ is derived from the Karst topography of the limestone region of Slovenia and North Italy. Karst Terrain is a landform consisting of limestone or other carbonate rocks such as dolomite that have been influenced by the dissolving action of carbonic acid. It is characterized by underground drainage systems with sinkholes and caves as well as springs, streams and other forms of surface water. Karst areas are characterized by a range of landscape features, including disappearing streams, surface creeks that temporarily flow on the surface and then vanish into the subsurface, sinkholes, karren (tafoni, lapies and clintshield) and caves. Karst hydrology is an important element of these areas and can provide resources in the form of groundwater and it is also associated with certain risks, such as flooding and sinkhole formation.
Karst areas are particularly important in terms of biodiversity; as they host a range of species which are adapted to the specific environmental conditions. Karst landscapes also host significant limestone deposits and many associated resources in the form of calcite and other minerals. The presence of these resources makes karst landscapes important economically as well as environmentally.
The process of karsts development is a dynamic and complex one, ignited by acidic compounds, specifically the H2SO4 and HCl in rain water coming into contact with the limestone. This action causes the limestone to dissolve, resulting in the formation of caves, fissures and voids in the rock mass. As such, the development of karst topography is primarily related to the physical and chemical properties of the rock units. In practice, karst features normally appear only in mature karst terrains. A clear understanding of the hydrogeological behavior of the terrain is required for effective management and conservation of karst areas.
Karst surveys involve the collection of information regarding the landform, resources, hydrology and species of a given area. This information can be gathered by way of aerial photography, basic characterization of the landform (including mapping of the surface, visual analysis of geographic patterns, and census of the land use), and studies of the water balance (including data on the rates and types of erosion, the presence of springs and streams, the base-flow in river systems and the location of sinkholes). By collecting this type of information, it is possible to create 3-D models of the karst terrain and to understand how water moves through the subsurface.
The most common methods of acquiring the necessary information for karst studies are geological, geomorphic and geophysical surveys. Geological surveys are often employed to produce maps and geological profiles. Basic geological mapping can help to identify the distribution and type of rocks in a region. Geomorphic surveys involve mapping the surface features of the terrain and can include the use of aerial photography and Remote Sensing. Geophysical surveys are employed to collect data regarding the subsurface structure and lithology. Common techniques employed for karst investigations include seismic refraction, electrical resistivity surveys and ground penetrating radar (GPR).
By gathering data in this way, it is possible to produce 3-D models of the terrain which allow for simulation of the hydrology of the area. This has become increasingly important in terms of management and conservation of karst areas, as it can provide crucial information in terms of water resources and associated hazards such as flooding and sinkhole formation. In terms of conservation and management, it is also important to consider the species and biodiversity of a given karst area. Monitoring of these species and the habitats that they inhabit is an important part of karst surveys.
In summary, karst surveys are vitally important for the effective management and conservation of karst areas. The collection of data regarding the land form, resources, hydrology and species of the area can provide important hydrological information and can also be used to map and monitor species and habitats. Such surveys provide an important basis for the effective management and conservation of karst areas.
