Climate change is expected to affect not only the means of climatic variables, but also their variabilities1,2 and extremes such as heat waves2–6. In particular, modelling studies have postulated a possible impact of soil-moisture deficit and drought on hot extremes7–11. Such effects could be responsible for impending changes in the occurrence of heat waves in Europe7. Here we analyse observational indices based on measurements at 275 meteorological stations in central and southeastern Europe, and on publicly available gridded observations12. We find a relationship between soil-moisture deficit, as expressed by the standardized precipitation index13, and summer hot extremes in southeastern Europe. This relationship is stronger for the high end of the distribution of temperature extremes. We compare our results with simulations of current climate models and find that the models correctly represent the soil-moisture impacts on temperature extremes in southeastern Europe, but overestimate them in central Europe. Given the memory associated with soil moisture storage, our findings may help with climate-changeadaptation measures, such as early-warning and prediction tools for extreme heat wave

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Abstract. Physically based modelling of slope stability on a catchment scale is still a challenging task. When applying a physically based model on such a scale (1 : 10 000 to 1 : 50 000), parameters with a high impact on the model result should be calibrated to account for (i) the spatial variability of parameter values, (ii) shortcomings of the selected model, (iii) uncertainties of laboratory tests and field measurements or (iv) parameters that cannot be derived experimentally or measured in the field (e.g. calibration constants). While systematic parameter calibration is a common task in hydrological modelling, this is rarely done using physically based slope stability models. In the present study a dynamic, physically based, coupled hydrological-geomechanical slope stability model is calibrated based on a limited number of laboratory tests and a detailed multitemporal shallow landslide inventory covering two landslide-triggering rainfall events in the Laternser valley, Vorarlberg (Austria). Sensitive parameters are identified based on a local one-at-a-time sensitivity analysis. These parameters (hydraulic conductivity, specific storage, angle of internal friction for effective stress, cohesion for effective stress) are systematically sampled and calibrated for a landslide-triggering rainfall event in August 2005. The identified model ensemble, including 25 "behavioural model runs" with the highest portion of correctly predicted landslides and non-landslides, is then validated with another landslide-triggering rainfall event in May 1999. The identified model ensemble correctly predicts the location and the supposed triggering timing of 73.0 % of the observed landslides triggered in August 2005 and 91.5 % of the observed landslides triggered in May 1999. Results of the model ensemble driven with raised precipitation input reveal a slight increase in areas potentially affected by slope failure. At the same time, the peak run-off increases more markedly, suggesting that precipitation intensities during the investigated landslide-triggering rainfall events were already close to or above the soil's infiltration capacity.

In Europe, sandflies (Diptera: Psychodidae: Phlebotominae) are typical Mediterranean faunal elements of low expansivity, which are widely distributed in more than 20 species in many parts of Southern Europe. A few species have extended their distribution to the northwest invading extramediterranean regions (Western, Eastern Europe); any occurrence in Central Europe north of the Alps was excluded until recently. Since 1999 sandflies have been found in several parts in Germany and in Belgium; originally these records were ascribed to climate change and global warming. Meanwhile, the more likely assumption is that sandflies have always, probably since the Holocene climate optima (ca. 4500 and 2500 B.C.), been in Central Europe sporadically to where they have come as immigrants (or re-immigrants) from Mediterranean refugial areas. It is, however, without question that global warming will lead to an extension of the distributional areas of sandflies. A climatological analysis of the localities where sandflies have been found in Central Europe has revealed that temperature is the key factor. A comparison of climatological parameters in sandfly-localities with the climatic conditions in Austria (where sandflies have not yet been found) has shown that an increase of temperature by 1 degrees C in January (Ph. mascittii) or 1 degrees C in July (Ph. neglectus), respectively, would lead to suitable conditions for the occurrence of sandflies in certain parts of Austria. (The scenarios for an increase of temperature until the end of the century vary between 1.5 degrees C to 4.5 degrees C; 3 degrees C seem to be realistic also for critical climatologists.) Leishmaniae certainly do not occur in Central Europe primarily, but an increasing number of infections in humans, as well as in animals, acquired in Central Europe has been registered. It is highly likely that these infections are due to sandflies which have been infected by sucking blood on infected dogs. Dogs infected with Leishmania and presenting a variety of clinical symptoms are frequently brought by compassionate tourists from Mediterranean countries - often illegally - to Central Europe. Meanwhile, a flourishing market for dogs of miserable appearance suffering from leishmaniosis has been developed by profit-oriented opportunists in Mediterranean countries. With respect to the serious course of visceral leishmaniosis (particularly in infants and in immunocompromised persons) this dangerous condition merits intensive attention. Phleboviruses have not been found in Central Europe, so far. However, in the course of global warming an establishment of biological cycles after an introduction of the pathogens, particularly if vertebrates other than humans can also act as reservoir hosts, seems possible.

An increase in drought frequency, duration and severity is expected for the Central European region as a direct consequence of climate change. This will have profound effects on a number of key sectors (e.g. agriculture, forestry, energy production and tourism) and also affect water resources, biodiversity and the landscape as a whole. However, global circulation models significantly differ in their projections for Central Europe with respect to the magnitude and timing of these changes. Therefore, analysis of changes in drought characteristics during the last 54 yr in relation to prevailing climate trends might significantly enhance our understanding of present and future drought risks. This study is based on a set of drought indices, including the Standardized Precipitation Index (SPI), the Palmer Drought Severity Index (PDSI), the Palmer Zindex (Z-index) and the Standardized Precipitation−Evapotranspiration Index (SPEI), in their most advanced formulations. The time series of the drought indices were calculated for 411 climatological stations across Austria (excluding the Alps), the Czech Republic and Slovakia. Up to 45% of the evaluated stations (depending on the index) became significantly drier during the 1961−2014 period except for areas in the west and north of the studied region. In addition to identifying the regions with the most pronounced drying trends, a drying trend consistency across the station network of 3 independent national weather services was shown. The main driver behind this development was an increase in the evaporative demand of the atmosphere, driven by higher temperatures and global radiation with limited changes in precipitation totals. The observed drying trends were most pronounced during the April−September period and in lower elevations. Conversely, the majority of stations above 1000 m exhibited a significant wetting trend for both the summer and winter (October−March) half-years.

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