Evaluation and management of the risk of flooding river bank

Abstract

Climatic change caused by human activity will lead to intensification of hydrological cycle and will become a reason for extreme phenomena of even greater severity. Evaluation of flooding risk, their prediction and hydrological prevention are principal means to mitigate the outcomes of floods. Flooding risk means the probability of flood occurrence and outcomes of flood impact on natural and economic objects and population. A set of methods of theory of random processes and mathematical statistics allows obtaining a rational solution to this problem. There are three different problems occurring during the floods: reliability of hydraulic structures, overflowing and flooding the river floodplain (flooding risk) and washout of banks. The main task when exploring the flooding risk is determination of critical water level during the river overflow, determination of flooding areas at different levels and of different water discharges accordingly, and evaluation of damage in different situations. Peak discharges are usually calculated based on survey data of annual maximums. For evaluating the flooding risk, we propose to make the calculations of maximal discharges for individual months. In such cases, the genetic homogeneity of basic data is generally observed, and vaster information is processed and analyzed, seasonality of expected damages in agriculture is considered and most importantly, the maximums in different months are more predictable than seasonal and annual maximums. The prognostic models of monthly flows are developed for many rivers and work successfully. The performed calculations give a hope of designing a more efficient prognostic model of monthly maximum water discharges.