[M-IS01] Environmental, Socio-Economic and Climatic Changes in Northern Eurasia

[MIS01-P14] Assessing the past and future potential impacts of climate change on droughts in Uzbekistan

Natella Rakhmatova²、Bakhriddin E. Nishonov^3,2、Lyudmila Shardakova²、Valeriya Rakhmatova^2,4、Temur Khujanazarov⁴、*Dmitry Belikov¹ (1.Center for Environmental Remote Sensing, Chiba University、2.Hydrometeorological Research Institute, Center of Hydrometeorological Service of the Republic of Uzbekistan、3.Faculty of Hydrometeorology, National University of Uzbekistan、4.Disaster Prevention Research Institute, Kyoto University)

キーワード：Climate change, RCP and SSP scenarios, Uzbekistan, Central Asia

The Central Asia regions are highly vulnerable to the effects of global climate change due to their extremely delicate ecological environment. Previous research has revealed a notable increase in temperature throughout Central Asia, though the magnitude of this increase has varied. Nonetheless, despite differences in time periods and datasets, all large-scale studies have consistently confirmed a significant warming trend across the region, which has intensified in recent years. As a country located in Central Asia Uzbekistan has serious environmental problems that significantly impact people's livelihoods. These problems include the degradation of the Aral Sea, water deficit, increased desertification of land, and the frequent occurrence of extreme events, including prolonged droughts and frequent dust storms. Assessments of past and possible future climate change are relevant applied tasks that serve as the basis for developing timely measures and actions for adaptation in agriculture and water management and preparedness for meteorological hazards. In this study, we examined historical and projected climate changes in Uzbekistan over the period 1900–2100 using observations and the RCP (Representative Concentration Pathway) and SSP (Shared Socioeconomic Pathway) scenarios from CMIP5 and CMIP6. We assessed historical and future drought trends using the Standardized Precipitation and Evapotranspiration Index (SPEI) for a period of 12 months to reflect long-term precipitation anomalies.
Uzbekistan’s territory has different agroclimatic conditions, for the assessment, it was classified according to relatively homogeneous geographical features, climatic characteristics, and water supply conditions. Historical analysis confirms a sharp acceleration of the warming trend in Uzbekistan since the mid-1990s, with significant temperature increases observed. Seasonal analysis revealed the largest changes in temperature and precipitation during winter (Dec, Jan, and Feb) and spring (March, April, and May). These seasons are essential, as two-thirds of the annual precipitation amount falls during this time. Changes in rainfall patterns and shifting seasons can affect available water resources, and increase evaporation during the growing season, which will increase water scarcity and affect the growing season of crops and yields. A historical analysis of SPEI values revealed consistent patterns across all regions of Uzbekistan, indicating severe droughts in 2000-2001, 2008, and 2011.
Combining RCP and SSP scenarios provide a comprehensive outlook on the interactions between climate change and socioeconomic factors, and their impact on the country until 2100. Climate parameters and the SPEI index were calculated for the entire country by twenty-year periods and analyzed relative to the base period. A comparison of SPEI calculated using RCP and SSP scenarios suggests that SSP is less severe. All scenarios except highly unlikely SSP1.9 indicate increased aridity.