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.

中文翻译：

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欧洲中部纵断面的土壤干旱和循环类型

在可用于表征农业干旱的变量中，土壤干旱尤为重要。该贡献使用从1961-2019年期间的SoilClim模型计算出的网格土壤干旱值来分析中欧的四个低地，相对均质的地区的土壤干旱事件（基于第10个百分位数），提供了整个中欧的纵向横断面。这些地区主要位于海拔400 m asl以下，包括波希米亚中部，摩拉维亚南部和斯洛伐克，斯洛伐克南部和斯洛伐克东部的相邻部分。结果表明，在1990年之后，此类事件主要发生在夏季半年（4月至9月），并伴随着1961-2019年期间线性趋势的增加，而冬季半年（10月至3月）的情况则相反。选定的干旱事件进一步分为三个阶段（第一阶段-始发阶段，第二阶段-路线，第三阶段-结束阶段），并根据降水量和基于流强，方向和涡度的循环类型客观分类分别进行了调查。一，二期土壤干旱是造成干旱的一期和二期的原因，高降水气旋的频率降低和与日降水总量较高相关的定向类型，以及一期和二期土壤干旱，而三期则相反。循环类型对降水和土壤干旱发生的影响差异很大，尤其是波希米亚中部地区与其他三个地区相比。