150-year daily data (1870-2021) in lakes and rivers unveils escalating surface water warming and intensifying heatwaves in the Pannonian Ecoregion (Hungary)

Water temperature is a pivotal factor in determining the health and functionality of both lotic and lentic water ecosystems. Bridging the gap between atmospheric influences and aquatic environments, this study embarked on a comprehensive reconstruction of daily surface water temperatures across lakes and rivers within the Pannonian Ecoregion over an extensive period of 150 years (1870-2021). Leveraging the sophisticated air2water and air2stream models, we meticulously mapped the thermal dynamics of these vital water bodies, providing unparalleled insights into their historical temperature trends. The analysis revealed a clear warming trend in water temperatures over the past 150 years, with lakes experiencing a higher increase (0.073°C/decade) compared to rivers (0.046°C/decade) between 1870 and 2021. Seasonal patterns indicated that winter and spring exhibited faster warming rates, followed by summer and autumn. Additionally, there has been a significant increase in the frequency, duration, and intensity of heatwaves in lakes and rivers, particularly pronounced in the last 30 to 40 years. These findings underscore the escalating impact of climate change on freshwater systems in the Pannonian Ecoregion, emphasizing the urgent need for mitigation measures. The insights from this study are invaluable for informing freshwater management practices, including fish habitat management and ecosystem modelling, to address the challenges posed by the changing water temperatures and heatwave dynamics.

水温是决定流水型（lotic）与静水型（lentic）水生生态系统健康状态与功能运转的关键核心因素。本研究填补了大气影响与水生环境之间的研究空白，针对潘诺尼亚生态区（Pannonian Ecoregion）内的湖泊与河流，开展了长达150年（1870年至2021年）的逐日表层水温综合重建工作。借助先进的air2water与air2stream模型，本研究精细刻画了这些关键水体的热动力变化过程，为解析其历史水温变化趋势提供了前所未有的研究视角。分析结果显示，1870年至2021年的150年间，水体水温整体呈现显著变暖趋势，其中湖泊的水温升幅（0.073℃/十年）高于河流（0.046℃/十年）。季节变化模式表明，冬季与春季的变暖速率更快，夏季与秋季次之。此外，湖泊与河流的热浪发生频率、持续时长与强度均显著提升，这一趋势在近30至40年间尤为显著。本研究结果凸显了气候变化对潘诺尼亚生态区淡水生态系统的影响正日益加剧，强调了采取减缓措施的迫切性。本研究所得的见解可为淡水管理实践提供重要参考，涵盖鱼类栖息地管理与生态系统建模等领域，以应对水温变化与热浪动态带来的各类挑战。