Rainstorms impacts on water, sediment, and trace elements loads in an urbanized catchment within Moscow city: case study of summer 2020 and 2021

Abstract

In 2020 and 2021 the city of Moscow, Russia, has experienced two historical rainfall events that had caused major ooding of small rivers. Based on long-term observation datasets from the surrounding weather stations, regional mesoscale COSMO-CLM climate model results, and a detailed hydrological and water quality monitoring data collected in 2019-2021, we performed pioneer climate change and urbanization impact assessment on ooding hazard and water quality of case study urban Setun river. Statistically signi cant rise of moderate extremity indices and absence of signi cant trends for the most extreme indices was revealed for the 1966-2020 period. The combined impact of climate change and increased urbanization is highly non-linear and results in as much as a four-fold increase in extreme oods and shift of water regime features which lead to formation of speci c seasonal ow patterns. The rainstorm ood wave catchment response, involving in ltrated and hillslope-routed fraction of rainfall, is accounted as 6 to 11 hours, which it is more than twice as rapid as compared to the non-urbanized nearby catchments. Behaviour of four types of chemicals in the river water during rainstorms was identi ed, as well as main differences compared to the spring freshet period revealed. Based on the obtained results we conclude that lack of research focused on the combined impacts of climate change and urbanization on ooding and water quality in the Moscow urban area is a key problem in water management advances.

A Case Study on the Convection Initiation Mechanisms of an Extreme Rainstorm over the Northern Slope of Kunlun Mountains, Xinjiang, Northwest China

“…In the context of global climate warming, extreme precipitation events have become more frequent, leading to a significant increase in heavy precipitation [1][2][3][4][5]. Consequently, associated natural hazards such as flash floods, urban waterlogging, landslides, and debris flows are posing serious threats to society, the economy, and personal safety [6][7][8][9]. Despite substantial progress in comprehending the structure and lifespan of convective systems, accurately forecasting the convective initiation (CI, which refers to the process by which air particles gain and maintain positive buoyancy after being lifted above the level of free convection, eventually forming deep convective clouds) remains one of the biggest challenges in meteorology [10][11][12][13][14][15][16][17][18][19][20][21].…”