Second rock glacier inventory (RGI2) of Central and Eastern Austria, link to Shapefile

Rock glaciers are striking features in high mountain environments indicating permafrost conditions during the period of formation and activity. Within the framework of the Alpine-Space-Project PermaNET, a new polygon-based inventory of rock glaciers has been elaborated comprising the alpine areas of central and eastern Austria as part of an inventory covering the entire European Alps. The establishment of the new inventory was primarily based on an existing point-based inventory which was re-evaluated and amplified using currently available orthophotos, different digital elevation models and derivatives thereof. Further topographic information such as for instance elevation of lower and upper limits, maximum length and width, area and activity degree were gathered in an attribute table. All different parameters were analyzed regarding the entire investigation area, differences between the relevant federal provinces of Austria and between the single mountain regions. These regions were distinguished by differences of mainly climate, topography and present glacier extent. As a result, data on altogether 1647 rock glacier polygons or units were gathered in the inventory comprising 1430 monomorphic rock glaciers (rock glacier with one unit/generation) and 98 polymorphic rock glaciers (with two to five distinct units). 1300 rock glacier units have been classified as relict (no permafrost anymore) covering 97.7 km**2 in total, whereas 347 units with a total area of 21.3 km**2 as intact (containing permafrost) ones. The mean lower limit of relict rock glacier units with a mean size of 0.075 km**2 is situated at 2102 m a.s.l.. For the intact ones the respective values are 0.061 km**2 and 2515 m a.s.l.. Interpreting the results leads to the conclusion that the dominance of relict rock glaciers is due to fact that the summit elevations decrease towards the east thus restricting current permafrost occurrence to limited areas. Furthermore, "normal glaciers" still occupy rock glacier favourable sites particularly in central Austria. Intact rock glaciers usually developed over millennia primarily during the Holocene. In contrast, relict rock glaciers began to form during and after the Lateglacial deglaciation of cirques which generally occurred earlier in the east compared to the west of the investigated area. However, slope orientation was relevant for the deglaciation pattern causing formation of older rock glaciers on „warm“ slopes whereas on “cold” slopes rock glaciers are possibly of younger age. Although a comprehensive overview on rock glacier distribution can be given by our study, drawbacks of this study are the varying quality of information sources, the absence of data on surface motion (except for single rock glaciers) and missing absolute dating of rock glacier surfaces.岩石冰川（rock glacier）是高海拔山地环境中极具辨识度的地貌特征，其形成与活动时期均指示存在多年冻土（permafrost）条件。在阿尔卑斯空间项目永久冻土网络（Alpine-Space-Project PermaNET）框架下，针对覆盖整个欧洲阿尔卑斯山区的普查工作，研究团队针对奥地利中东部阿尔卑斯区域编制了一套全新的基于多边形的岩石冰川普查清单。本次新建普查清单的构建主要依托现有基于点的普查数据集，通过当前可用的正射影像（orthophotos）、多款数字高程模型（digital elevation models）及其衍生数据对原数据集进行重新评估与补充完善。属性表中收录了各类地形信息，例如上下限海拔、最大长宽、面积与活动程度等参数。针对整个研究区域、奥地利各相关联邦州以及单个山地分区之间的差异，研究团队对所有采集的参数开展了分析。上述山地分区主要依据气候、地形与现有冰川分布差异进行划分。本次普查最终共收录1647处岩石冰川多边形或单元，其中包括1430处单形态岩石冰川（即仅含单个单元/世代的岩石冰川）与98处多形态岩石冰川（含2至5个独立单元）。其中1300处岩石冰川单元被归类为遗迹型（已无多年冻土），总面积达97.7平方千米；另有347处单元被判定为存续型（仍含多年冻土），总面积为21.3平方千米。遗迹型岩石冰川单元的平均面积为0.075平方千米，其平均下限海拔为2102米海拔高程（a.s.l.，above sea level）；存续型单元的对应参数分别为0.061平方千米与2515米海拔高程。对结果的解读表明，遗迹型岩石冰川占主导地位的原因在于：研究区域的主峰海拔自西向东逐渐降低，导致当前多年冻土的分布仅局限于有限区域。此外，‘常规冰川’仍占据着适宜岩石冰川发育的区域，尤其在奥地利中部地区。存续型岩石冰川通常在全新世期间历经数千年逐步形成。与之相反，遗迹型岩石冰川的形成始于冰斗晚冰期冰消作用（Lateglacial deglaciation）时期及之后，而研究区域东部的冰斗冰消作用普遍早于西部。不过，坡向（slope orientation）对冰消作用模式存在影响：‘暖坡’上可能形成年代更久远的岩石冰川，而‘冷坡’上的岩石冰川形成年代则相对较新。尽管本研究可全面呈现岩石冰川的分布概况，但仍存在诸多局限：信息源的质量参差不齐，缺乏除个别岩石冰川外的表面运动数据，且未对岩石冰川表面开展绝对年代测定。