Синоптические условия повышения уровня рек на юге Иркутской области и Забайкалья в июле 2023 года

Abstract

The article discusses natural and anthropogenic factors of rising river levels and associated environmental consequences, existing probabilistic estimates of the amount of floods using various hydrological and climate models. Orographic, climatic and circulation features of the occurrence of floods in the Irkutsk region are identified. A study was carried out of the circulation and weather factors of increasing the intensity and duration of precipitation in early July 2023, which was accompanied by an increase in river levels in the south of the Irkutsk region and the Baikal region. The dynamics of atmospheric processes near the Earth's surface and at the levels of isobaric surfaces AT850 hPa, AT-700 hPa, AT-500 hPa and AT-300 hPa, reflecting the conditions of surface and highaltitude cyclo- and frontogenesis, are analyzed. The contribution of advective flows of heat and moisture, mesojets in the middle troposphere and upper tropospheric jet currents in increasing the amount and duration of atmospheric precipitation is highlighted. A significant contribution to the increase in precipitation and the rise in river levels was made by moist air masses moving in the lower troposphere from the water area of the lake. Baikal, in the middle troposphere from the Yellow Sea. The time of passage of the flood and the height of the rise in the level of individual watercourses as a result of the rains were estimated.