Changes in the frequency, magnitude, and seasonality of hydrological extremes are one of the expected consequences of climate change. Recent years suggested an increasing risk of drought occurrence and restricted water supply even in usually humid mountain regions. Our research is focused on the evaluation of regional climate change and its effect on hydrological drought characteristics in headwater areas in the Ore Mountains along the Czech/German border. The main aim was to evaluate and compare streamflow regime changes and trends in long-term hydrological and climatic time series within selected sub-catchments of the Svatava (Zwota) River, the Rolava River, and the Načetínský Brook (Natzschung). A comparative statistical analysis for the 1967–2018 period was performed using various homogeneity and trend tests. Longer runoff time series with earlier beginnings were examined for two catchments as well. The results pointed to significant, continuous warming in the region which is accompanied by decreasing trends in snow cover depths in the colder half of the year. Drought indices based on runoff data were derived in the Indicators of Hydrologic Alterations (IHA 7.1) software environment. The seasonality of hydrological drought occurrence changed markedly after 1992, when most severe drought events started to concentrate between August and October in the study area. Increasing trends in deficit volumes were found in two catchments characterized by lower elevation. Furthermore, there was a significant decrease in average and minimum flows in spring and summer months in all catchments observed between 1967 and 2018 despite relatively stable amounts of precipitation and land cover.

中文翻译：

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区域气候变化对矿石山源头水文干旱特征的影响

水文极端事件的频率、幅度和季节性变化是气候变化的预期后果之一。近年来，即使在通常潮湿的山区，发生干旱和供水受限的风险也在增加。我们的研究重点是评估区域气候变化及其对捷克/德国边境矿山上游地区水文干旱特征的影响。主要目的是评估和比较 Svatava (Zwota) 河、Rolava 河和 Načetínský Brook (Natzschung) 选定子流域内长期水文和气候时间序列的流量状态变化和趋势。使用各种同质性和趋势检验对 1967-2018 年期间进行了比较统计分析。还对两个集水区进行了较早开始的较长径流时间序列的检查。结果表明，该地区显着、持续的变暖伴随着一年中较冷的半年积雪深度呈下降趋势。基于径流数据的干旱指数是在水文变化指标 (IHA 7.1) 软件环境中得出的。1992年以后，水文干旱发生的季节性发生明显变化，最严重的干旱事件开始集中在研究区的8-10月之间。在海拔较低的两个流域中发现了赤字量增加的趋势。此外，