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Central Europe has experienced a sequence of unprecedented summer droughts since 2015, which had considerable effects on the functioning and productivity of natural and agricultural systems. Placing these recent extremes in a long-term context of natural climate variability is, however, constrained by the limited length of observational records. Here, we use tree-ring stable oxygen and carbon isotopes to develop annually resolved reconstructions of growing season temperature and summer moisture variability for central Europe during the past 2,000 years. Both records are independently interpolated across the southern Czech Republic and northeastern Austria to produce explicit estimates of the optimum agroclimatic zones, based on modern references of climatic forcing. Historical documentation of agricultural productivity and climate variability since 1090 CE provides strong quantitative verification of our new reconstructions. Our isotope records not only contain clear expressions of the Medieval (920-1000 CE) and Renaissance (early 16th century) droughts, but also the relative influence of temperature and moisture on hydroclimatic conditions during the first millennium (including previously reported pluvials during the early 3rd, 5th, and 7th centuries CE). We conclude, Czech agricultural production has experienced significant extremes over the past 2,000 years, which includes periods for which there are no modern analogues.

In the Czech Republic, soil moisture content during the growing season has been decreasing over the past six decades, and drought events have become significantly more frequent. In 2003, 2015, 2018 and 2019, drought affected almost the entire country, with droughts in 2000, 2004, 2007, 2012, 2014 and 2017 having smaller extents but still severe intensities in some regions. The current methods of visiting cadastral areas (approximately 13,000) to allocate compensation funds for the crop yield losses caused by drought or aggregating the losses to district areas (approximately 1000 km2) based on proxy data are both inappropriate. The former due to the required time and resources, the later due to low resolution, which leads to many falsely negative and falsely positive results. Therefore, the study presents a new method to combine ground survey, remotely sensed and model data for determining crop yield losses. The study shows that it is possible to estimate them at the cadastral area level in the Czech Republic and attribute those losses to drought. This can be done with remotely sensed vegetation, water stress and soil moisture conditions with modeled soil moisture anomalies coupled with near-real-time feedback from reporters and with crop status surveys. The newly developed approach allowed the achievement of a proportion of falsely positive errors of less than 10% (e.g., oat 2%, 8%; spring barley 4%, 3%; sugar beets 2%, 21%; and winter wheat 2%, 6% in years 2017, resp. 2018) and allowed for cutting the loss assessment time from eight months in 2017 to eight weeks in 2018.

Soil moisture is a key factor for plant growth and agricultural production. Therefore, it has become a fundamental part of agricultural drought monitoring systems developed for various spatial scales ranging from local to regional and global. Despite the development of large-scale soil moisture monitoring systems, in-situ soil moisture observations still remain inadequate for precise soil moisture monitoring, especially in remote areas, where there is a limited number of monitoring stations. Together with remote sensing technologies soil moisture modeling may provide an alternative to in-situ measurements that delivers spatially continuous estimates over large geographic areas. SoilClim is a semi-empirical water balance model that, together with other outputs (e.g., reference and actual evapotranspiration, soil temperature), estimates daily soil moisture in various depths of soil profile. The model has previously been validated on a total of 20 sites (5 in Central Europe and 15 in central USA) and is now used for global monitoring and prediction of soil moisture and drought intensity in an operational and interactive web platform (www.windy.com). Our study evaluates the SoilClim soil moisture global measurements with 0.1° spatial resolution using two independent sources of information: i) in-situ soil moisture measurements from the International Soil Moisture Network, and ii) the soil moisture derived from the Metop ASCAT sensors on Metop-A and Metop-B satellites. In the conference presentation we will introduce the SoilClim model and present results of the global validation including statistical spatial analysis and triple collocation.Acknowledgement: This study was conducted with support of SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797).

The most reliable method for monitoring plant phenology and changes in vegetation development is ground observation (in-situ). However, this method is difficult to implement on a larger spatial scale. For that reason, remote sensing data have begun to be used to quantify vegetation phenology in recent decades. Information about phenology is derived from remote sensing data using ie. phenological metrics. In this study, we used 3 base metrics - the start of the growing season (SOS), the end of the growing season (EOS), and the length of the growing season (LGS) for evaluating changes in the phenology of four land covers (coniferous forest, broadleaf forest, field, and grassland) in the European region (approx. 30 countries). For their determination, Enhanced Vegetation Index2 (EVI2) was used based on images from The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Satellite images were obtained at a spatial resolution of 5 x 5 km in the time period from 2000 to 2022. For four land covers within the 22-year period, it was evaluated that the SOS significantly shifted to an earlier date in about half of the evaluated states. The EOS significantly shifted to a later date in almost all evaluated states. Based on these results, we evaluated the whole length of the growing season and found a significant shift to a later date also in almost all evaluated states.Acknowledgement: This work was supported by an individual IGA project - Determination of vegetation time and its spatiotemporal variability using remote sensing of the Earth (AF-IGA2022-IP-067) and by SustES project – Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797), which provided essential data and software access.

Annual and seasonal temperature, precipitation, and drought index (SPI – standard precipitation index, SPEI – standard precipitation evapotranspiration index, Z index, PDSI – Palmer Drought Severity Index) series covering the Czech Lands territory (now the Czech Republic) over 520 years (1501–2020 CE) reconstructed from documentary data combined with instrumental observations were analysed herein. The temperature series exhibits a statistically significant increasing trend, rising from ∼ 1890 and particularly from the 1970s; 1991–2020 represents the warmest and driest 30-year period since 1501 CE. While the long-term precipitation total fluctuations (and derived SPI fluctuations) remain relatively stable with annual and decadal variabilities, past temperature increases are the key factor affecting recent increasing dryness in the SPEI, Z index, and PDSI series. The seasonal temperature series represent a broad European area, while the seasonal precipitation series show lower spatial correlations. A statistical attribution analysis conducted utilizing regression and wavelet techniques confirmed the influence of covariates related to volcanic activity (prompting temporary temperature decreases, especially during summer) and the North Atlantic Oscillation (influential in all seasons except summer) in the Czech climate reconstructions. Furthermore, components tied to multidecadal variabilities in the northern Atlantic and northern Pacific were identified in the temperature and precipitation series and in the drought indices, revealing notable shared oscillations, particularly at periods of approximately 70–100 years.

This paper describes a comprehensive online database of giant landslides on volcanic islands compiled by researchers from the Institute of Rock Structure and Mechanics, Czech Academy of Sciences, in the framework of IPL Project 212. The database was constructed from 2016 to 2018. It comprises a total of seventy-five events from the Atlantic Ocean and Mediterranean Sea, sixty-seven events from the Pacific Ocean, and forty events from the Indian Ocean. In this paper some of the main benefits of landslide inventories and thematic databases are outlined and the global distribution of giant landslides on volcanic islands is described in depth. The database is hosted on the website of the Institute of Rock Structure & Mechanics and records can be downloaded as a spreadsheet or kml file for integration in a number of geospatial programs including ArcGIS and Google Earth. However, since completion of the database in 2018, a number of potentially significant studies of giant landslides on volcanic islands have been published from archipelagos in the Atlantic and Pacific Oceans while outstanding modern analogues for past events are represented by the collapse of Anak Krakatau on 22 December 2018 and the collapse of Hunga Tonga-Hunga Haʻapai on 15 January 2022. Consequently, the recent literature will be scrutinized with the aim of updating information already contained in the database while two new layers are planned: the first of these will provide information about recent volcanic collapses and the second will provide information about the long-term instrumental monitoring of giant landslides. It is intended that the second release of the database will be available online in early 2023.

The paper shows a large-scale shift in agroclimatic zones in the territory of the Czech Republic (CR) between 1961 and 2019. The method used for agroclimatic zoning took advantage of high-resolution (0.5 km × 0.5 km) daily climate data collected from 268 climatological and 787 rain-gauge stations. The climate information was combined with soil and terrain data at the same resolution. The set of seven agroclimatic indicators allowed us to estimate rates of changes in agroclimatic conditions over the 1961–2019 period, including changes in the air temperature regime, global radiation, drought, frost risks and snow cover occurrence. These indicators are relevant for all main crops and agroclimatic zoning and account for local soil and slope conditions. The study clearly highlights major shifts in the type and extent of agroclimatic zones between 1961–2000 and 2000–2019, which led to the occurrence of entirely new combinations of agroclimatic indicators.

Multi-centennial- to millennial-long oak (Quercus spp.) tree-ring width (TRW) chronologies from living and relict wood are frequently used for climate reconstructions, but the amount of explained hydroclimatic variation remains relatively small. Although stable carbon and oxygen isotopic ratios (δ13C and δ18O values) in tree rings may offer enhanced climate sensitivity, our understanding of their paleoclimatic sensitivity is still limited by the general lack of well-replicated and high-resolution datasets. Here, we assessed the temperature, precipitation, and drought signal of annual δ13C and δ18O values and TRW measurements from 21 oaks growing under different ecological settings in the Czech Republic. Compared to the overall low climate sensitivity of TRW, the δ13C and δ18O chronologies revealed significant positive and negative correlations with March-August mean temperature and hydroclimate (for the period 1901-2018), respectively. Additional tests on the effect of sample size demonstrated robust climate sensitivity of the isotopic chronologies when non-pooled alpha cellulose from the latewood of at least 6 individual oaks was used. Our study suggests that oak stable isotopes are possibly the best high-resolution paleoclimatic proxy for the Central European lowlands, as well as any other temperate habitat where oak wood has historically been used as construction timber, and where traditional tree-ring parameters, such as TRW, tend to fail.

Grasslands play a significant role in livestock fodder production and thus, contribute to food security worldwide while providing numerous additional ecosystem services. However, how agroclimatic conditions and adverse weather events relevant for grasslands will change across the European grassland areas has not been examined to date. Using a single reference setup for soil and management over 476 European sites defined by climate stations, we show the probability of eight selected adverse weather events with the potential to significantly affect grassland productivity under climate change and how these events vary regionally across Europe. Changes in these eight key agroclimatic indicators create markedly specific spatial patterns. We found that by 2050, the exposure of the south and west European grasslands to heat and drought may double in comparison with today and that the area with frequent occurrences of heat and drought will expand northwards. However, across Ukraine, Belarus, and the Baltic countries to southern Finland and Sweden, the likelihood of these events is likely to decrease. While changing cultivars and management strategies are unavoidable, shifting grassland production to other regions to reduce the risk may not be possible as the risk of adverse events beyond the key grassland-growing areas increases even further. Moreover, we found marked changes in the overall thermal and water regimes across European regions. The effect of adverse weather events in the future could be different in other regions of the world compared to regions in Europe, emphasizing the importance of conducting similar analyses for other major grassland producing regions. To mitigate the impact of climate change, new ways of maintaining grassland productivity need to be developed. These methods include more efficient selection of species mixtures for specific regions, including increased use of legumes and forbs; incorporation of new genetic resources, including the development of hybrid cultivars, such as Festulolium hybrids; and incorporation of state-of-the-art technologies in breeding programs and new grazing management.

Investigation of the relationship between climatological variables and circulation patterns expressed by various classifications of circulation types is a key procedure in synoptic climatology. This study provides new insights into circulation drivers of hydroclimate based on an analysis of precipitation and soil drought in multiple parts of the Czech Republic with respect to the subjective classification of the Czech Hydrometeorological Institute and objective classification based on the flow strength, flow direction, and vorticity during the 1961–2020 period. Circulation types are investigated in regard to their contributions to the total precipitation, mean daily precipitation totals, and precipitation probability. Types with a westerly airflow and a trough over Central Europe exhibit the highest proportions in precipitation totals. Types with a cyclone over Central Europe, especially combined with a northwestern or northeastern airflow, result in the highest daily mean totals and precipitation probability. Types with a southwestern airflow transport more precipitation to western parts of the Czech Republic, while those with a northeastern airflow transport more precipitation to the eastern parts, with a slight seasonal shift in the gradient axis between winter and summer. Circulation drivers of drought episodes are investigated based on soil-drought values calculated from the SoilClim model. Increased frequencies of north-eastern anticyclonic types, and decreased frequencies of directional and cyclonic are important for the origin and course of soil-drought episodes. In addition, the suitability of both classifications for long-term trends analysis is investigated.

Despite their pivotal role in climate research, direct instrumental records of meteorological variables are only available for the most recent part of climate history. Even in regions with longest tradition of weather measurements, such as central Europe, the existing series rarely comprise more than two centuries of reliable data. However, documentary sources, both quantitative and qualitative, can be employed to substantially extend the available records. Using the resulting multi-centennial data, previously unexplored features of climate system’s evolution can then be studied.In this analysis, temporal variability in annual and seasonal series of temperature, precipitation and drought indices (Standardized Precipitation Index - SPI, Standardized Precipitation Evapotranspiration Index - SPEI, Z-index), pertaining to the territory of contemporary Czechia, has been studied over the 1501–2020 CE period. The series under investigation were reconstructed from multitude of Czech documentary data sources, combined with instrumental observations. Phenoclimatic temperature and SPEI reconstructions, derived from historical records of cereal and grape harvest dates, were also employed and compared to their documentary-based counterparts.Statistical attribution analysis, utilizing multiple linear regression, confirmed the influence of covariates related to volcanic activity (prompting temporary temperature decreases, especially during summer) and the North Atlantic Oscillation (influential in all seasons except summer for all target variables) in the Czech climate reconstructions. Statistically significant components correlated with multidecadal variability in the northern Atlantic and northern Pacific (represented by multiproxy-reconstructed AMO and PDO indices) were identified in the Czech temperature and precipitation series as well as in all drought indices. Additionally, using wavelet and cross-wavelet analysis, notable oscillations shared by the AMO/PDO variations and the Czech climate series were found, particularly at periods of approximately 70–100 years.

Crop rotation, fertilization and residue management affect the water balance and crop production and can lead to different sensitivities to climate change. To assess the impacts of climate change on crop rotations (CRs), the crop model ensemble (APSIM,AQUACROP, CROPSYST, DAISY, DSSAT, HERMES, MONICA) was used. The yields and water balance of two CRs with the same set of crops (winter wheat, silage maize, spring barley and winter rape) in a continuous transient run from 1961 to 2080 were simulated. CR1 was without cover crops and without manure application. Straw after the harvest was exported from the fields. CR2 included cover crops, manure application and crop residue retention left on field. Simulations were performed using two soil types (Chernozem, Cambisol) within three sites in the Czech Republic, which represent temperature and precipitation gradients for crops in Central Europe. For the description of future climatic conditions, seven climate scenarios were used. Six of them had increasing CO2 concentrations according RCP 8.5, one had no CO2 increase in the future. The output of an ensemble expected higher productivity by 0.82 t/ha/year and 2.04 t/ha/year for yields and aboveground biomass in the future (2051–2080). However, if the direct effect of a CO2 increase is not considered, the average yields for lowlands will be lower. Compared to CR1, CR2 showed higher average yields of 1.26 t/ha/year for current climatic conditions and 1.41 t/ha/year for future climatic conditions. For the majority of climate change scenarios, the crop model ensemble agrees on the projected yield increase in C3 crops in the future for CR2 but not for CR1. Higher agreement for future yield increases was found for Chernozem,while for Cambisol, lower yields under dry climate scenarios are expected. For silage maize, changes in simulated yields depend on locality. If the same hybrid will be used in the future, then yield reductions should be expected within lower altitudes. The results indicate the potential for higher biomass production from cover crops, but CR2 is associated with almost 120 mm higher evapotranspiration compared to that of CR1 over a 5-year cycle for lowland stations in the future, which in the case of the rainfed agriculture could affect the long-term soil water balance. This could affect groundwater replenishment, especially for locations with fine textured soils, although the findings of this study highlight the potential for the soil water-holding capacity to buffer against the adverse weather conditions.

Annual and seasonal temperature, precipitation and drought index (SPI, SPEI, Z-index, PDSI) series covering the Czech Lands territory (now the Czech Republic) over 520 years (1501–2020 CE) reconstructed from documentary data combined with instrumental observations were analysed herein. The temperature series exhibits a statistically significant increasing trend, rising from ~1890 and particularly from the 1970s; 1991–2020 represents the warmest and driest 30-year period since 1501 CE. While the long-term precipitation total fluctuations (and derived SPI fluctuations) remain relatively stable with annual and decadal variabilities, past temperature increases are the key factor affecting recent increasing dryness in the SPEI, Z-index and PDSI series. The seasonal temperature series represent a broad European area, while the seasonal precipitation series show lower spatial correlations. A statistical attribution analysis conducted utilizing regression and wavelet techniques confirmed the influence of covariates related to volcanic activity (prompting temporary temperature decreases, especially during summer) and the North Atlantic Oscillation (influential in all seasons except summer) in the Czech climate reconstructions. Furthermore, components tied to multidecadal variabilities in the northern Atlantic and northern Pacific were identified in the temperature and precipitation series and in the drought indices, revealing notable shared oscillations, particularly at periods of approximately 70–100 years.

Many studies in Europe have investigated the relationship between climatological variables and circulation patterns expressed by various classifications of circulation types. This study provides new insights based on an analysis of precipitation in the western (Bohemia—BOH) and eastern (Moravia and Silesia—M&S) parts of the Czech Republic with respect to the subjective classification of the Czech Hydrometeorological Institute and objective classification based on the flow strength, flow direction, and vorticity during the 1961–2020 period. Circulation types are investigated in regard to their contributions to the total precipitation, mean daily precipitation totals, and precipitation probability (daily totals ≥ 1.0 mm). Types with a westerly airflow and a trough over Central Europe exhibit the highest proportions in precipitation totals. Types with a cyclone over Central Europe, especially combined with a northwestern (BOH) or northeastern (M&S) airflow, result in the highest daily mean totals and precipitation probability. Types with a southwestern airflow transport more precipitation to BOH, while those with a northeastern airflow transport more precipitation to M&S, with a slight seasonal shift in the gradient axis between winter and summer. Circulation types under both classifications are examined from the perspective of their precipitation representation in BOH and M&S and the differences between these two regions. In addition, the suitability of both classifications for precipitation analysis is investigated.

The first comprehensive global database of giant landslides on volcanic islands is outlined in this report. This database comprises a total of one hundred and eighty-two entries: the Atlantic Ocean hosts seventy-five giant landslides; the Pacific Ocean hosts sixty-seven giant landslides; and the Indian Ocean hosts forty giant landslides. To determine the spatial characteristics of each giant landslide, it has been necessary to georeference published maps using ArcGIS software coupled with global DTMs. Using the georeferenced outputs, it has been possible to measure the basic morphometric characteristics of each landslide such as its length, width, perimeter, area, and fall height. Landslide volumes have been calculated with a higher degree of certainty in thirty-five cases and with a lower degree of certainty in sixty-three cases while complete outlines of the landslide area have been defined in ninety-six cases. On the basis of these data, it has been possible to interrogate relationships between potentially significant variables. The age distribution of giant landslides on volcanic islands demonstrates that more than half of the records in the database occurred during the last 0.5 Ma. This global database of giant landslides on volcanic islands is hosted on the website of the Institute of Rock Structure & Mechanics: https://www.irsm.cas.cz/ext/giantlandslides . From there, the records can be downloaded as a spreadsheet or as a kml file for interrogation in a number of geospatial software programs including ArcGIS and Google Earth. This work is part of the activities of the International Consortium on landslides, namely, its International Programme on Landslides (Project No. 212).

Drought directly and indirectly affects human society in a number of ways. In many regions of the world climate change will exasperate the effects of droughts, affect national economies more intensely. The main aim of this article was to catalogue and analyze the drought impacts in the 11 Central and South Eastern European states located in the Danube river basin. The identification of dry episodes was based on information from publicly available sources, namely, newspaper and journal articles that reported drought impacts. Information on drought impact occurrences was classified into one of five defined categories in which the drought impact report was most clearly manifested (i.e., agriculture, forestry, soil systems, wildfires and hydrology). In terms of the spatial distribution of drought impacts, individual recorded events were analyzed at the level of EU NUTS regions (or their equivalent in non-EU countries). The analysis highlights country-specific vulnerability to drought. Furthermore, gradual increases in drought events and the number of reported impacts were identified, which was particularly evident in the agricultural sector.

A one-dimensional simulation model that simulates daily mean soil temperature on a daily time-step basis, named AGRISOTES (AGRIcultural SOil TEmperature Simulation), is described. It considers ground coverage by biomass or a snow layer and accounts for the freeze/thaw effect of soil water. The model is designed for use on agricultural land with limited (and mostly easily available) input data, for estimating soil temperature spatial patterns, for single sites (as a stand-alone version), or in context with agrometeorological and agronomic models. The calibration and validation of the model are carried out on measured soil temperatures in experimental fields and other measurement sites with various climates, agricultural land uses and soil conditions in Europe. The model validation shows good results, but they are determined strongly by the quality and representativeness of the measured or estimated input parameters to which the model is most sensitive, particularly soil cover dynamics (biomass and snow cover), soil pore volume, soil texture and water content over the soil column. ispartof: Atmosphere vol:12 issue:4 status: published

This study quantified the crop water consumption, crop-specific irrigation requirements, and availability of water resources to catchments under climate change in the Czech Republic (CZ). Within the SoilClim model and BILAN-WATERES hydrological water balance modeling process, we tried to answer the question of whether there are at least theoretical water resources in the individual catchments of the CZ that could cover possible higher demands for irrigation. An ensemble of five global climate models under the moderate representative concentration pathway (RCP4.5) from the EURO-CORDEX initiative was chosen to project the future water use indicators. The irrigation water requirement indicators for the growing season (GS) of vineyards, hop gardens, orchards, vegetables, and fodder crops were calculated in 1143 catchments for two periods, 2031–2050 (Sc1) and 2061–2080 (Sc2), compared to the observed period 1961–2020 (Obs). To project irrigation scenarios in agricultural water management, the following water use indicators were quantified: relative soil moisture at 0–40 cm (AWR1) and 0–100 cm (AWR), crop water balance (Rain-ETa), irrigation water requirement (Irrig), and the ratio of actual and reference evapotranspiration (ETratio). To assess areas with a critically low water supply and quantify the frequency of water deficit during the GS of each crop, we calculated the number of days with extreme values of water use indicators. Quantification of the extreme irrigation characteristics reflected the highest depletion of soil moisture and the highest water demands, i.e., when the assessed indicators reached the 25th percentiles. For highly marketable vegetables, the largest deficit in Rain-ETa during the GS for Sc1 was projected. If current vegetable growing areas and cropping systems remain unchanged, Irrig will increase by 10.2% by the end of the 21st century under RCP4.5. Although current potato planting areas have soils with a high available water capacity, they will become controlled by the water deficit over the next few decades. The accumulated vineyard water required suggests that 15% and 25% of irrigation water will be lost by evaporation from the soil surface during the 2030s and 2080s, respectively. However, changes in future hopyard irrigation extent and amounts may have important implications in largely cropped irrigation hotspots. In the main traditional hop region for the 2030s, we project a 25% depletion of soil moisture and an increase of ETratio

Among the variables that can be employed to characterize agricultural drought, soil drought is of particular importance. This contribution uses gridded soil-drought values calculated from the SoilClim model for the 1961-2019 period to analyse soil drought episodes (based on the 10th percentile) in four lowlands, relatively homogeneous regions in central Europe that provide a longitudinal transect over central Europe. These areas are predominantly located at altitudes of below 400 m asl and include central Bohemia, southern Moravia and an adjacent part of Slovakia, southern Slovakia and eastern Slovakia. The results indicate that, after 1990, such episodes occurred largely in the summer half-year (April-September), accompanied by an increasing linear trend in the 1961-2019 period, while the situation was reversed in the winter half-year (October-March). Selected drought episodes are further divided into three phases (Phase I - origin, Phase II - course, Phase III - end) and investigated separately in terms of precipitation and objective classification of circulation types based on flow strength, direction and vorticity. Decreases in the frequency of precipitation-rich cyclonic and the directional types associated with higher daily precipitation totals, together with increases in precipitation-poor anticyclonic types, were responsible for soil-drought Phases I and II, with the opposite pertaining to Phase III. Differences in the effects of circulation types on precipitation and soil-drought occurrence were considerable, particularly for central Bohemia compared with the other three regions. The results obtained are also discussed with respect to data uncertainty and their broader spatiotemporal context.

Soil drought has an important influence on plant development. The SoilClim model was used to investigate episodes of soil drought with 10-year return periods at the 0–100-cm profile during the 1961–2017 period for four selected regions of the Czech Republic (North-western Bohemia, Southern Bohemia, North-eastern Moravia, and Southern Moravia). It emerged that the frequency of soil drought significantly increases in the summer half-year (SHY) and exhibits insignificant trends in the winter half-year (WHY). The dynamic climatology of soil drought is based herein upon synoptic situations as classified by the Czech Hydrometeorological Institute, in terms of which changes in the occurrence and precipitation intensity of drought episodes in the four individual regions were studied. Drought episodes are generally related to decreases in the frequency of precipitation-rich situations and in their precipitation intensity. This is particularly true of situations C (central cyclone over central Europe), B (trough over central Europe) and Bp (travelling trough). Situations B and Bp, together with south-west cyclonic situations SWc1-3, appeared as the most relevant to regional differences in drought episodes during SHY in the four regions studied, while western cyclonic situations (Wc and Wcs) emerged as particularly important in WHY. Regional differences are clearly marked between the Bohemian and Moravian regions, especially in SHY. Discussion of the results obtained concentrates on the uncertainty of soil drought data, differences between SHY and WHY, the effects of synoptic situations, and the broader context of soil droughts.

International audience; Crop rotation composition, fertilization strategy and residue management could have long term effects on soil properties and crop production. Due to system complexity and unceasing changes (e.g. the development climatic conditions) exact quantification of various factors is relatively complicated. Crop growth models are available tools for assessment of interactions and processes (crop development, biomass production, soil processes, flow of matters etc.) at various levels of agrosystems. This makes such tools very useful aside field experiment which has limited range of options and conditions. The aim of this study is to demonstrate functionality of HERMES crop model for simulations of long term uninterrupted crop rotations. The evaluation of the model behavior within recent period is described for selected soil-climatic conditions (examples for representative locations within Czech Republic) with focus both on crop production aspects and soil processes (including organic matter balance). Moreover the examples of the simulated processes by HERMES model under selected set of future climatic conditions during this century is presented. Based on acquired knowledges the challenges for further progress is described (e.g. crops mixtures modelling, new crop implementation, effect of tillage intensity). The ambition is to have the complex and reliable modelling procedure as a tool for possible adaptation measures design and assessment both for current and future climatic condition. The study and contribution was funded through SustES-Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions" project no. CZ.02.1.01/0.0/0.0/16_019/0000797.

Volcanic flank collapses often result in giant debris avalanches that are capable of travelling tens of kilometres across the ocean floor and generating tsunamis that devastate distant communities. The San Andres Landslide on El Hierro, Canary Islands, represents one of the few places in the world where it is possible to investigate the landslide mass and fault planes of a volcanic collapse structure. In this study, a new conceptual model for the development of this enormous slump is presented on the basis of structural geological and geomorphological measurements, petrological and microstructural analyses, and cosmogenic radionuclide dating. Structural geological and geomorphological measurements indicate that the fault plane records two distinct events. Petrological and microstructural analyses demonstrate that a thin layer of frictionite covers the surface of the fault in contact with an oxidised tectonic breccia that transitions into the underlying undeformed basanite host rock. This frictionite comprises a heterogeneous cataclastic layer and a translucent silica layer that are interpreted to represent two separate slip events on the basis of their architecture and crosscutting relationships. Cosmogenic 3He dating reveals a maximum exposure age of 183 ± 17 ka to 52 ± 17 ka. Arguments are presented in support of the idea that the first slip event took place between 545 ka and 430 ka, prior to significant clockwise rotation of El Hierro, and the second slip event took place between 183 ka and 52 ka, perhaps in association with one of the giant debris avalanches that occurred around that time. This is the first time that more than one slip event has been recognised from the fault plane of the San Andres Landslide. It is also believed to be the first time a silica layer resulting from frictional melt has been described in a volcanic setting.