SEASONAL CHANGES IN PRECIPITATION EXTREMES IN RUSSIA FOR THE LAST SEVERAL DECADES AND THEIR IMPACT ON VITAL ACTIVITIES OF THE HUMAN POPULATION

摘要

Seasonal regional features of the daily precipitation extremes were studied based on Russian meteorological stations datasets for the period of 1991- 2013 compared to the 1961-1990 climate baseline conditions. Precipitation extreme changes were assessed for the most vulnerable regions of Russia with high population density, where precipitation extremes result in negative impacts on the environment and human activities. It was found that the frequency of precipitation extremes in winter and in spring for the period 1991-2013 significantly increased, by 20-40% at the average, in most parts of the case study area. Due to positive trends in daily precipitation extremes changes which was revealed for the winter and spring periods (not exceeding on average 0.2 mm/day/decade), the risks of catastrophic spring floods have been analysed, especially in the areas with a higher recurrence rate of dangerous floods, i.e. - the South Urals region and the Altai region. Strong positive trends of extreme precipitation changes were observed in the Russian Far East region. It indicates higher risk of summer rain floods in the Amur River basin. A significant impact on human activities and in particular population health is associated with revealed trends in hydrological cycle changes that are not relevant to typical meteorological and hydrological regimes. The significant increase of the frequency of extreme summer precipitation events in the Central Chernozem region of European Russia in the period of 1961-2013 was accompanied by the leptospirosis disease incidences.