{'fraction_non_alphanumeric': 0.021233569261880688, 'fraction_numerical': 0.020222446916076844, 'mean_word_length': 4.925149700598802, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Relict rock glaciers as important aquifers in sensitive ecosystems: The example of the Natura 2000 protection area Niedere Tauern Range, Styria

The hydrological significance of active rock glaciers for water storage is studied since the mid 1970ies. In contrast, the hydrology of relict rock glaciers lacking permafrost today is still poorly understood. Despite this shortage of knowledge, relict rock glaciers and their hydrogeology are important in the alpine landscape of Austria. In this study we focussed on the European protection area (Natura 2000) Niedere Tauern (surface area 1261 km2) located in Styria, Austria. At the regional scale the spatial distribution of relict rock glaciers and their catchment areas were investigated. Results show that the drainage of approximately 9% of the area above 1500 m a.s.l. and 23 % above 2000 m a.sl. are influenced by relict rock glaciers as aquifers. Results of the subunit Seckauer Tauern Range even show 16% above 1500 m a.s.l. and 42% above 2000 m a.s.l. At a local scale the hydraulic properties of a relict rock glacier are investigated at the Schöneben Rock Glacier with a distinct spring at the front. Hydrograph analyses indicate for instance both a fast component on groundwater recharge events with a low storage capacity and a base flow component with a high storage capacity. The spring hydrograph can be decomposed in three exponential recession functions with different recession coefficients depending on the range of discharge. This indicates a multi-storage system. Our results clearly indicate that on a regional scale relict rock glaciers are highly relevant for the drainage system and ecology in the studied alpine region. On a local scale it is shown that rock glaciers are not only essential water buffers in alpine catchments relevant for ecosystems (continuous water supply during dry periods) but also natural hazards (flood-risk reduction after storm events) and are essential groundwater resources.