Assessing the impact of climate change on meteorological parameters in the Sakarya River Basin using advanced trend analysis methods

Abstract

The increasing frequency of extreme weather events highlights the urgent need to raise public awareness about climate change indicators and the atmospheric changes driven by human activities and pollution. To better understand these developments, region-specific analyses of recorded climate data over time are essential. This study analyzes 30 years of climate data from the Sakarya River Basin, using measurements collected by meteorological stations operated by the Turkish General Directorate of Meteorology at various locations and altitudes across the basin. Seventeen stations were selected for analysis, focusing on daily average precipitation, temperature, and relative humidity three key indicators of regional climate behavior. Relationships among these variables were examined using Pearson correlation analysis, while trends were analyzed through Spearman's Rho, Sen's Slope, Mann-Kendall, and the Crossing Empirical Trend Analysis (CETA) method. The findings revealed that relative humidity showed a 37 % increase and a 22 % decrease, temperature increased by 36 % and decreased by 1 %, and precipitation increased and decreased equally by 20 %. These results point to growing irregularities in the basin's climate structure, with the rise in temperature and variability in humidity and precipitation indicating heightened risks of drought, floods, and other extreme weather events. By incorporating multiple complementary analytical techniques, this research presents a detailed evaluation of shifting climate patterns in the Sakarya River Basin and offers a strong foundation for future environmental planning and climate-resilient policy development.