Study of Snow Cover Characteristics According to the Data of Meteorological Stations of Western Kazakhstan in the Context of Global Climate Change

Abstract

In the Republic of Kazakhstan, runoff in lowland rivers is 90% determined by snowmelt. Therefore, assessing snow reserves in a changing climate is of great scientific and applied importance. This work aims to assess how global climate change affects snow cover characteristics in Western Kazakhstan in the Caspian Sea basin. For the first time, we conducted a comprehensive assessment of snow cover depth, water equivalent, and snow cover duration in the drainage basin. We used statistical analysis of data from 50 meteorological stations for the period 1950–2024. Only data from 14 meteorological stations in the Mugalzhar lowlands (north of the Aktobe region) and on the Podural plateau (north of the West Kazakhstan region), where errors did not exceed 2–4%, were suitable for climate studies. The results showed an increase in average snow height by 3 cm, a decrease in maximum height by 4 cm, and a 17-day reduction in the duration of stable snow cover. However, these trends are not statistically significant (the coefficient of determination is 0.02–0.24), and their values fall within the statistical error. The calculated Pearson and Spearman indicators confirm a statistical relationship between individual global and regional climate indicators (correlation coefficients of 0.23–0.40 at the significance level p = 0.03). However, most snow cover indicators show no statistical dependence: correlation coefficients range from −0.02 to 0.20, with p = 0.30–0.90. The results obtained indicate a random, stochastic nature of the long-term dynamics of depth, water equivalent, and duration of snow cover in the region under study.