October to July precipitation reconstruction for Burabai region (Kazakhstan) since 1744

摘要

The history of climate is crucially important for any part of the world to understand the nature of climate change. In this context, precipitation reconstruction is still lacking in northern Kazakhstan. The purpose of this study is to present a reconstruction for the total precipitation of October of the previous year to July of the current year in northern Kazakhstan. Pinus sylvestris L. (Scots pine) forests in Burabai Region are quite important to collect samples to study the climate history. A regional chronology, covering the years of 1702-2014 of Pinus sylvestris constructed by using 289/466 trees/cores was used in the reconstruction. The gridded climate data for the years of 1950-2014 were used in the calibration and verification process. High and significant correlations were obtained between tree-ring widths and October to July precipitation in Burabai Region. Based on this significant relationship, reconstruction was performed for the years of 1744-2014. Adjusted R-2, F-value, sign test, and r value were found as 0.38, 39.7 (P <= 0.001), 47+/17, and 0.62 for reconstruction, respectively. The reconstruction showed that 43 dry and 42 wet years occurred during the years of 1744-2014. Only a one-time four-year duration of the wet period was determined covering the years 1978-1981. However, three of six very dry years occurred after the 1950s. As a conclusion, extremity in recent decades is getting an increase in Burabai region.