Geographical analysis of river flood hazard in Siberia

Siberia is a huge and relatively sparsely populated territory in the centre of Eurasia with a harsh climate and diverse flow formation conditions. Nevertheless, it is characterized by a high flood hazard, as most of the settlements and industrial centres are located along river banks. The flood hazard can vary across space and time against a background of climatic and anthropogenic changes, as well as socio-economic factors. We carried out a geographical analysis of floods as a tool to identify the present status of flood hazard in Siberia. The analysis included: analysis of flood hazard during a period of climatic change (1985-2016); analysis of ice jams and ice dams as a specific natural factor causing floods; and identification of areas with different flood hazards using multi-scale mapping. Rainfall floods, mixed floods (due to rainfall and snowmelt) and floods resulting from ice dams are the most dangerous in Siberia. They have the highest rate of recurrence, strength of impact, and number of fatalities and displaced people. The locations of areas with different flood hazards were identified by multi-scale mapping. The highest flood hazard in Siberia is in the most populated and economically developed southern regions along the Ob, Lena, Yenisei rivers and in the Lake Baikal basin. In areas with a high flood hazard, complex measures are needed, taking into account regional peculiarities.