Abstract. Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins: the Zakza river in the center of East European Plane (southwest of the Moscow), the Dubna river (north of the Moscow) and the Sosna river in the south of central region. Samples of river water, groundwater and precipitation for the October 2019–October 2021 were collected at weekly intervals. A significant supply of melted snow during spring freshet is the key factor influencing water regimes for these three river basins; varying degrees of anthropogenic flow regulation are also present. During the observation period, there were fundamentally two completely different conditions in terms of runoff formation. First, October 2019–October 2020, there was abnormal low spring freshet instead there was high rain flood in summer. In October 2020–October 2021 there was a normal intra-annual flow pattern with high spring freshet. The new data of stable isotope signature of river runoff component can help to study the response of a river runoff to changing climate conditions.

中文翻译：

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东欧平原中部三个流域河流径流、地下水和降水的稳定同位素（δ18O、δ2H）特征

摘要。在 3 个不同流域的三个水文站对河流径流的同位素特征进行了实证研究：东欧平面中心的 Zakza 河（莫斯科西南部）、杜布纳河（莫斯科北部）和中部地区南部的索斯纳河。每周收集 2019 年 10 月至 2021 年 10 月的河水、地下水和降水样本。春季淡水期间大量融雪供应是影响这三个流域水情的关键因素；也存在不同程度的人为流量调节。在观测期间，从根本上来说，径流形成有两种完全不同的情况。首先，2019 年 10 月至 2020 年 10 月，春季降水异常偏低，夏季降雨量大。2020 年 10 月至 2021 年 10 月，年内流量正常，春季新鲜度高。河流径流成分稳定同位素特征的新数据有助于研究河流径流对气候条件变化的响应。