Orolbo‘yida iqlim o‘zgarishi trendlari va ularning tuproq sho‘rlanishiga ta’siri: statistik tahlil

Abstract

The aim of the study is to assess climate change trends in the Aral Sea region over 1982-2024 and to determine their relationship with soil salinization. Using NASA POWER (MERRA-2) reanalysis data for the Nukus, Muynak and Khiva sites, trends in air temperature, precipitation, potential evapotranspiration by the Thornthwaite method and the aridity index were analyzed with the Mann-Kendall test and Sen’s slope. Anomalous monthly values in the precipitation series were removed with a statistical filter. The results showed no statistically significant trend in mean annual temperature; however, spring (March-May) temperature increased significantly at all three sites, by 0.42-0.49 °C per decade (p < 0.01). The Pettitt test revealed a shift in mean temperature of 0.54-0.61 °C after 1996, although this shift is not statistically significant. Annual precipitation increased by 6-14 mm per decade, and potential evapotranspiration by 7-8 mm. Nevertheless, the region remains in the dry (arid) climate category, with an annual water deficit of 755-855 mm. In Khorezm region, the severity of salinization is strongly negatively correlated with the aridity index. The findings indicate the need to adjust the timing of leaching and irrigation to spring warming and to integrate climate monitoring with salinity monitoring.