Home – Home – Jornals – Geography and Natural Resources 2020 number 4

The problem of estimating the probable maximum values of the inflow to the Zeya reservoir on the basis of determining maximum probable precipitation and results from simulating the flood runoff formation is considered. The maximum probable daily precipitation amounts were determined by the hydrometeorological method using the data of eight-term station-based me teorological observations of dew point temperature and precipitation amounts. Maximum daily precipitation values were con verted to those for the travel time of the flood wave via the channel system (seven days for the Zeya basin) using the transition coefficient obtained by a statistical processing of precipitation amounts of different durations. To calculate the possible maximum flood, a rain graph with 1-day sampling intervals was constructed according to the type of change in precipitation intensity dur ing the maximum flood observed in 2013. Precipitation was recalculated to the runoff in terms of the deterministic model devel oped by the Hydrologic Engineering Center (USA) with due regard for the formation characteristic of heavy floods in the settings of permafrost. The calculated limiting value of the inflow was refined using the Bayesian method of constructing a probability curve taking into account the upper limit of the distribution and the specified determination error of the desired characteristic. The values obtained for the maximum flow of the Zeya are compared with its estimates available to date.