[1] Changes of rock and ice temperature inside permafrost rock walls crucially affect their stability. Permafrost rocks at the Zugspitze were involved in a 0.3-0.4 km 3 rockfall at 3.7 ka B.P. whose deposits are now inhabited by several thousands of people. A 107 year climate record at the summit (2962 m asl) shows a sharp temperature increase in 1991-2007. This article applies electrical resistivity tomography (ERT) to gain insight into spatial thaw and refreezing behavior of permafrost rocks and presents the first approach to calibrating ERT with frozen rock temperature. High-resolution ERT was conducted in the north face adjacent to the Zugspitze rockfall scarp in February and monthly from May to October 2007. A smoothness-constrained inversion is employed with an incorporated data error model, calibrated on the basis of normal reciprocal measurement discrepancy. Laboratory analysis of Zugspitze limestone indicates a bilinear temperature-resistivity relationship divided by a 0.5 ± 0.1°C and 30 ± 3 kWm equilibrium freezing point and a twentyfold increase of the frozen temperature-resistivity gradient (19.3 ± 2.1 kWm/°C). Temperature dominates resistivity changes in rock below −0.5°C, while in this case geological parameters are less important. ERT shows recession and readvance of frozen conditions in rock correspondingly to temperature data. Maximum resistivity changes in depths up to 27 m coincide with maximum measured water flow in fractures in May. Here we show that laboratory-calibrated ERT does not only identify frozen and unfrozen rock but provides quantitative information on frozen rock temperature relevant for stability considerations.Citation: Krautblatter, M., S. Verleysdonk, A. Flores-Orozco, and A. Kemna (2010), Temperature-calibrated imaging of seasonal changes in permafrost rock walls by quantitative electrical resistivity tomography (Zugspitze, German/Austrian Alps),

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Integrating both modeling approach and stakeholders’ perspectives to derive past and future trends of land use land cover (LULC) is a key to creating more realistic results on LULC change trajectories and can lead to the implementation of appropriate management measures. This article assessed the past changes of LULC in the Mono River catchment using Landsat images from the years 1986, 2000, 2010, and 2020 by performing Machine Learning Classification Method Random Forest (RF) technique, and using Markov Chain method and stakeholder’s perspective to simulate future LULC changes for the years 2030 and 2050. LULC was classified as savanna, cropland, forest, water bodies, and settlement. The results showed that croplands and forests areas declined from 2020 to 2050 with decreases of −7.8% and −1.9%, respectively, a modest increase in settlement (1.3%), and savanna was the dominant LULC in the study region with an increase of 8.5%. From stakeholders’ perspective, rapid population growth, deforestation, rainfall variability/flood, urbanization, and agricultural expansion were the most important drivers associated with the observed LULC changes in the area. Other factors, such as lack of political commitment, distance to river, and elevation were also mentioned. Additionally, most the land-use scenarios identified by stakeholders would intensify land degradation and reduce ecosystem services in the area. By considering all of these potential LULC changes, decision-makers need to develop and implement appropriate solutions (e.g., land use planning strategies, reforestation campaigns, forest protection measures) in order to limit the negative effects of future LULC changes.

This article is an attempt to transfer a classical geomorphological concept -the sensitivity concept by Brunsden and Thornes -onto mountain permafrost systems. Focus is put on the impulses applied on the system and its subsequent response. The system state, the ratio between sensitivity and resistivity, as well as all system components and the external impulses are understood to be variable in space and time. In order to address sensitivity and path dependence in mountain permafrost systems, not only the present system configuration but also their historical development and possible future attractors have to be analysed. Important elements are the system configuration, variable impulses and thresholds, processes and process rates and internal feedbacks. The Zugspitze in the Northern Calcareous Alps at the German/Austrian border is chosen as a test site for the applicability of the sensitivity concept on mountain permafrost systems due to the high quantity of research conducted there and the significant impact of climate change on the periglacial system. Further aspects include the consequences of the Eibsee Bergsturz event in 3700 BP in terms of path dependence and geomorphic response time. With this conceptual approach, we hope (1) to enhance the interlinkage between periglacial geomorphology and other sub-disciplines of geomorphology, (2) to contribute to the strengthening of the conceptual basis of periglacial geomorphology, and, therefore, (3) to strengthen the possibilities for holistic exchange within the cryospheric research community.

Le permafrost et ses modifications dans les parois rocheuses de haute montagne restent insuffisamment compris, en particulier du fait de la rareté des sites instrumentés. D"où l"intérêt de développer des recherches à l"Aiguille du Midi (3842 m), aux expositions et pentes variées, et dont les parois et galeries sont accessibles toute l"année. Dans le cadre du projet PermaNET, nous y suivons le régime thermique dans la roche, (i) avec une vingtaine de thermistors implantés jusqu"à 55 cm de profondeur ; (ii) par tomographie électrique résistive, sur la base de la relation température/résistivité du granite local ; (iii) par thermographie infrarouge sur les parois. Ces mesures sont complétées par deux stations météo automatiques mobiles, tandis qu"il est prévu l"installation de chaînes de thermistors d"une dizaine de m de profondeur. Ces données seront utilisées pour valider des modèles physiques ou construire des modèles statistiques de la distribution de la température de la roche et sa variabilité. Par ailleurs, un MNT à haute résolution réalisé à l"aide de laserscans terrestres longue (pour les parois) et courte (dans les galeries) portées servira de support à la modélisation numérique de (i) la fracturation de la roche et de la circulation d"eau dans les fractures non saturées ; (ii) la distribution 3-D et de l"évolution des températures de subsurface. Enfin, le suivi de la face SE de l"Arête des Cosmiques à l"aide d"un laserscan terrestre longue portée complète des datations cosmogéniques sur certaines parois pour documenter la morphodynamique passée et actuelle du site. MOTS-CLÉS Permafrost, régime thermique de la roche, laserscan terrestre, tomographie électrique résistive, massif du Mont Blanc ABSTRACT Permafrost and its change in steep high-Alpine rock walls remain insufficiently understood especially because of a few existing instrumented sites. Thus, it is very interesting to develop investigations at the Aiguille du Midi (3842 m a.s.l), which rockwalls with diverse aspects and slopes, and galleries are year-round accessible. In the framework of the project PermaNET, we monitor the rock thermal regime, (i) with c.20 thermistors installed up to 55 cm deep; (ii) using electrical resistivity tomography (ERT), based on the temperatureresistivity relationship of the local granite; (iii) by infrared thermography on the rockwalls. These measurements are completed by two movable automatic weather stations, while the installation of thermistor chains up to a depth of 10 m is planned. These data will be used for physically-based model validation or statistical models construction of rock temperature distribution and variability in the rock walls. A 3D-high-resolution DEM made using long-range (rock walls) and short-range (galleries) terrestrial laser scanning will help for numerical modelling of (i) rock fractures and water flow in unsaturated fractures; (ii) the 3-D distribution and evolution of temperature fields in the subsurface. Finally, monitoring of the Arête des Cosmiques SE face-SE Pilastre by long-range t...

Recurrent floods have become a major problem in the transboundary Lower Mono River catchment of Togo and Benin, causing more damage and loss of life than any other disaster in the area. The level of understanding about floods and their management can be as diverse as the groups within the communities and thus can present a variety of perspectives. People tend to perceive flood risk and management differently due to their proximity to flood-prone areas and their level of vulnerability as well as their capacity to adapt. Therefore, this study explores the specific perspectives of local communities and experts on floods in the transboundary Mono catchment, which can help to inform better adaptation strategies according to the contexts of each community. We conducted series of focus groups discussions (FGDs) using the Actors, Resources, Dynamics, and Interactions (ARDI) framework to develop mental models of flood management. This approach allowed us to identify the causes and impact of flooding in the area, and to describe the actors and effects of flood events on the main natural resources as well as the dynamics and interactions that drive change and influence flood management in the study area. The results indicate that the perceptions of local communities and experts show both similarities and differences. These differences include (1) perceptions of relevant direct actors, (2) perceptions of resources at stake, and (3) actor-specific resource utilization. Considering these dissimilar views between expert and local community knowledge systems appears to be an important contributing factor to improving flood mitigation efforts in the catchment. Adapting risk communication and measures taken for flood management in accordance with the perceptions of affected communities could greatly increase success, with positive long-term effects for the involved institutions and communities regarding mutual trust-building.