Human impact to the karst of the Franconian Alb, Germany

The Franconian Alb, located in southeastern Germany, consists of karstified limestones and dolomites of Jurassic Age. It is partly covered by Cretaceous and Miocene deposits and a clayey to loamy overburden. Hydrogeologically, it is separated into a shallow and a deep karst zone. Humans using the different natural framework requirements formed the actual cultural landscape of the area. Depending on the spatial distribution of limestones, dolomites and cover deposits the surface is used by agriculture and forestry. Caused by different percentages of these aspects in the catchment areas karst springs exhibit different chemical compositions with respect to chloride, nitrate, phosphate and other substances. Especially the shallow karst and transitional zone to deep karst show such characteristics. Since a long time the Franconian Alb was affected by exploiting of the natural resources. Mining of iron ore ended twenty years ago in the eastern part of the Franconian Alb. For most of the karst area this human impact has been overcome in the natural scenery and mining remains only as a local touristic aspect. Nowadays the pit and quarry industry exert a large influence to the karst area and locally it is the main branch of the economy. The natural stones were extracted since several hundred years within several quarries to use them for different purposes (e.g. staircases, window sills, wall claddings, building stones). Several parts of the Franconian Alb were declared to natural parks and they are subject to special environmental regulations. Nevertheless the industrial and agricultural use of the landscape persists but it is liable to a number of restrictions. Additionally, different large-scale projects affected the area in the last twenty-five years. The construction of the Rhine-Danube canal, extension of several highways and the construction of high-speed train routes were the main impacts.