DETECTION OF THE CHANGE POINT IN ICE FORMATION DATES

Abstract

In recent years, there has been an increasing interest in studies related to the impact of climatic changes on the ice regime of water bodies. This paper aims to detect the change point in the ice formation dates for Kamskoe Reservoir. This is done with the use of an improved methodological approach. The results revealed that the greatest deviations are observed when comparing time intervals after 1995. The last decade of the observation period (2008–2018) was characterized by significant changes in late dates. According to the Data Series Smoothing method, the change point for the observation series falls on 1996. Differential Integral Curves of the ice dates show that the beginning of the significant climatic changes is noted in 1995–1997. The rejection of the randomness hypothesis indicates the presence of significant changes in the ice dates for 1956–2018 for all gauges, except Berezniki. The deviation of the homogeneity hypothesis for the ice dates in 1956–1995 and 1996–2018 shows the presence of statistically significant changes at the turn of 1996. Thus, the impact of modern climatic changes on the ice dates has been observed over the last 25 years, with the change point falling on 1996.