Abstract. Hydrological time series (HTS) are the key basis of water
conservancy project planning and construction. However, under the influence
of climate change, human activities and other factors, the consistency of
HTS has been destroyed and cannot meet the requirements of mathematical
statistics. Series division and wavelet transform are effective methods to
reuse and analyse HTS. However, they are limited by the change-point
detection and mother wavelet (MWT) selection and are difficult to apply and
promote in practice. To address these issues, we constructed a potential
change-point set based on a cumulative anomaly method, the Mann–Kendall test and
wavelet change-point detection. Then, the degree of change before and after
the potential change point was calculated with the Kolmogorov–Smirnov test,
and the change-point detection criteria were proposed. Finally, the
optimization framework was proposed according to the detection accuracy of
MWT, and continuous wavelet transform was used to analyse HTS evolution. We
used Pingshan station and Yichang station on the Yangtze River as study
cases. The results show that (1) change-point detection criteria can quickly
locate potential change points, determine the change trajectory and complete
the division of HTS and that (2) MWT optimal framework can select the MWT that
conforms to HTS characteristics and ensure the accuracy and uniqueness of
the transformation. This study analyses the HTS evolution and provides a
better basis for hydrological and hydraulic calculation, which will improve
design flood estimation and operation scheme preparation.