Agro-meteorological trends of recent climate development in Khorezm and implications for crop production

The extremely continental climate in the inner Aral Sea Basin is characterized by a high annual temperature amplitude, and constantly very low ­precipitation. Climate change in the Khorezm region, a district of Uzbekistan ­dominated by extensive irrigation agriculture, is manifest by temperature increases, especially during the winter period (40-year record). The 10-year average of ­summer temperatures in 1981–1990 was 0.2–0.5°C above the long-term average in 1930–1990. Time series of agro-meteorological parameters based on data (air and soil temperature, relative humidity, wind speed, precipitation, and radiation) of three meteorological stations in Khorezm revealed (a) air temperatures supporting good growing conditions for cotton, rice, wheat, sorghum, and maize; (b) comparatively good air and soil temperature conditions for cotton production; and (c) no negative climate impact on regional water demands for irrigation yet. Moderate spatial variability was observed between climate in the central irrigation system, at its southern ­margin to the desert, and in the desert itself (represented by the stations Urgench, Khiva, and Tuyamuyun, respectively).