Comparative Analysis of Vulnerability Mapping Methods on a Hungarian Karst Area

In Hungary, 65% of the drinking water is supplied from vulnerable aquifers. Karst aquifers are especially important water resources, and due to their 3D impact surface, they are specially sensitive systems. Vulnerability maps are expressive and easily understandable, and they can provide adequate information for decision-makers to plan sustainable land use and water management. Many methods exist to analyze and map vulnerability, but for now in Hungary there is no generally adopted method to assess this property of the groundwater resources.

To examine the intrinsic resource vulnerability of a typical karstic area in Hungary, in our work we evaluated and combined the lithological, pedological, meteorological, hydrological and geomorphological characterics and data of the studied area, and we applied different existing vulnerability mapping methods (e.g., European Approach, COP Method, Slovene Approach). Following the analysis and comparison of the resulting maps, the aim of our study was to test the applicability of these methods in Hungarian test sites, and bring into light their incompletenesses, as a first step to develop a vulnerability mapping method appropriate for the Hungarian circumstances, taking into account the special characteristics of Hungarian karst aquifer systems.

Our test site is the semi-confined Tapolcai Karst, which is connected to important drinking and thermal water sources, but it lies outside of the borders of the protected Balaton Uplands National Park. This area is strongly influenced by many different anthropogenic effects and processes: grazing, considerable alterations in karst water level caused by mining in the 20th century (especially in the 70s), and the high number of illegal waste deposit sites.